diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
deleted file mode 100644
index a1d58a77c..000000000
--- a/.github/CODEOWNERS
+++ /dev/null
@@ -1,7 +0,0 @@
-# Code owners file.
-# This file controls who is tagged for review for any given pull request.
-#
-# For syntax help see:
-# https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners#codeowners-syntax
-
-*     @googleapis/actools-java @googleapis/yoshi-java @googleapis/cloud-java-team-teamsync
diff --git a/.github/snippet-bot.yml b/.github/snippet-bot.yml
deleted file mode 100644
index 1488c14ec..000000000
--- a/.github/snippet-bot.yml
+++ /dev/null
@@ -1,2 +0,0 @@
-aggregateChecks: false
-alwaysCreateStatusCheck: false
diff --git a/.github/sync-repo-settings.yaml b/.github/sync-repo-settings.yaml
deleted file mode 100644
index 4ff4f40b1..000000000
--- a/.github/sync-repo-settings.yaml
+++ /dev/null
@@ -1,45 +0,0 @@
-rebaseMergeAllowed: false
-squashMergeAllowed: true
-mergeCommitAllowed: false
-branchProtectionRules:
-  - pattern: main
-    isAdminEnforced: true
-    requiredApprovingReviewCount: 1
-    requiresCodeOwnerReviews: true
-    requiresStrictStatusChecks: false
-    requiredStatusCheckContexts:
-      - bazel
-      - units (8)
-      - units (11)
-      - cla/google
-  - pattern: 2.16.x
-    isAdminEnforced: true
-    requiredApprovingReviewCount: 1
-    requiresCodeOwnerReviews: true
-    requiresStrictStatusChecks: true
-    requiredStatusCheckContexts:
-      - bazel
-      - units (8)
-      - units (11)
-      - cla/google
-  - pattern: 2.19.x
-    isAdminEnforced: true
-    requiredApprovingReviewCount: 1
-    requiresCodeOwnerReviews: true
-    requiresStrictStatusChecks: false
-    requiredStatusCheckContexts:
-      - bazel
-      - units (8)
-      - units (11)
-      - cla/google
-permissionRules:
-  - team: yoshi-admins
-    permission: admin
-  - team: yoshi-java-admins
-    permission: admin
-  - team: yoshi-java
-    permission: push
-  - team: actools
-    permission: admin
-  - team: actools-java
-    permission: push
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
deleted file mode 100644
index b05c1da3d..000000000
--- a/.github/workflows/ci.yaml
+++ /dev/null
@@ -1,113 +0,0 @@
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-name: ci
-jobs:
-  clirr:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-java@v3
-        with:
-          distribution: temurin
-          java-version: 8
-      - run: echo "JAVA8_HOME=${JAVA_HOME}" >> $GITHUB_ENV
-      - uses: actions/setup-java@v3
-        with:
-          distribution: temurin
-          java-version: 11
-      - run: echo "JAVA11_HOME=${JAVA_HOME}" >> $GITHUB_ENV
-      - run: .kokoro/build.sh
-        env:
-          JOB_TYPE: clirr
-  units-java11:
-    name: "units (11)"
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-java@v3
-        with:
-          java-version: 11
-          distribution: zulu
-      - run: java -version
-      - run: .kokoro/build.sh
-        env:
-          JOB_TYPE: test
-  units-java8:
-    name: "units (8)"
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v3
-    # Java 8 tests uses JDK 11 to compile and JDK 8 to run tests. See .kokoro/
-    # build.sh for the setup.
-    - uses: actions/setup-java@v3
-      with:
-        java-version: 8
-        distribution: zulu
-    - run: echo "JAVA8_HOME=${JAVA_HOME}" >> $GITHUB_ENV
-    - uses: actions/setup-java@v3
-      with:
-        java-version: 11
-        distribution: zulu
-    - run: echo "JAVA11_HOME=${JAVA_HOME}" >> $GITHUB_ENV
-    - run: printenv
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: test
-  bazel:
-    runs-on: ubuntu-latest
-    # Not using a container. The ubuntu-latest has Bazel 4.2 installed as of
-    # November 2021. gRPC 1.42 requires Bazel 4.
-    # https://github.com/grpc/grpc-java/pull/7598
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-java@v1
-        with:
-          java-version: 8
-      - run: java -version
-
-      - name: Bazel File Cache Setup
-        id: cache-bazel
-        uses: actions/cache@v3
-        with:
-          path: ~/.cache/bazel
-          key: ${{ runner.os }}-bazel-20210105-${{ secrets.CACHE_VERSION }}
-
-      - name: Bazel Cache Not Found
-        if: steps.cache-bazel.outputs.cache-hit != 'true'
-        run: |
-          echo "No cache found."
-      - name: Bazel Cache Found
-        if: steps.cache-bazel.outputs.cache-hit == 'true'
-        run: |
-          echo -n "Cache found. Cache size: "
-          du -sh ~/.cache/bazel
-          echo "If the cache seems broken, update the CACHE_VERSION secret in"
-          echo "https://github.com/googleapis/googleapis-discovery/settings/secrets/actions"
-          echo "(use any random string, any GUID will work)"
-          echo "and it will start over with a clean cache."
-          echo "The old one will disappear after 7 days."
-
-      - name: Run bazel tests
-        run: |
-          which bazel
-          bazel --version
-          bazel --batch test //... --noshow_progress --test_output=errors
-
-      - uses: actions/upload-artifact@v3
-        if: ${{ failure() }}
-        with:
-          name: test-artifacts
-          path: ~/.cache/bazel/*/*/*/gax-java/bazel-out/*/testlogs/*
-          retention-days: 5
-  requirements:
-    name: "requirements"
-    runs-on: ubuntu-latest
-    container: gcr.io/cloud-devrel-public-resources/java8
-    steps:
-      - uses: actions/checkout@v2
-      - run: |
-          python3 --version
-          python3 -m pip install --require-hashes -r .kokoro/requirements.txt
diff --git a/.github/workflows/downstream-native-image.yaml b/.github/workflows/downstream-native-image.yaml
deleted file mode 100644
index 5e0b4431c..000000000
--- a/.github/workflows/downstream-native-image.yaml
+++ /dev/null
@@ -1,41 +0,0 @@
-on:
-  push:
-    branches:
-    - main
-  pull_request:
-
-# Keeping this file separate as the dependencies check would use more
-# repositories than needed this downstream check for GraalVM native image
-# compilation.
-name: downstream
-jobs:
-  # GraalVM job ensures the compatibility of GraaVM version
-  graalvm:
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        graalvm: [22.3.0]
-        java: [11, 17]
-        repo:
-        # GAPIC library that doesn't use a real GCP project in integration tests
-        - orgpolicy
-    steps:
-    - uses: actions/checkout@v2
-    - uses: stCarolas/setup-maven@v4
-      with:
-        maven-version: 3.8.1
-    - uses: ayltai/setup-graalvm@v1
-      with:
-        java-version: ${{matrix.java}}
-        # When a new version of native-maven-plugin fails to run in a downstream
-        # library, it's likely to be an incompatibility with the GraalVM version.
-        # In that case, you need to upgrade the Docker container used in the
-        # tests in the downstream repositories (not just this value below).
-        # Example: https://github.com/googleapis/testing-infra-docker/pull/195
-        graalvm-version: ${{matrix.graalvm}}
-        native-image: true
-    - run: java -version
-    - run: sudo apt-get update -y
-    - run: sudo apt-get install libxml2-utils
-    - run: .kokoro/downstream-client-library-check.sh ${{matrix.repo}} graalvm
diff --git a/.github/workflows/downstream.yaml b/.github/workflows/downstream.yaml
deleted file mode 100644
index 45e45fa25..000000000
--- a/.github/workflows/downstream.yaml
+++ /dev/null
@@ -1,144 +0,0 @@
-on:
-  pull_request:
-    types: [ labeled ]
-    branches:
-    - main
-name: downstream
-jobs:
-  dependencies:
-    if: ${{ github.event.label.name == 'downstream-check:run' }}
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        java: [11]
-        repo:
-        # This list needs to be updated manually until an automated solution is in place.
-        - accessapproval
-        - accesscontextmanager
-        - aiplatform
-        - analytics-admin
-        - analytics-data
-        - api-gateway
-        - apigee-connect
-        - appengine-admin
-        - area120-tables
-        - artifact-registry
-        - asset
-        - assured-workloads
-        - automl
-        - bigquery
-        - bigqueryconnection
-        - bigquerydatatransfer
-        - bigquerymigration
-        - bigqueryreservation
-        - bigtable
-        - billing
-        - billingbudgets
-        - binary-authorization
-        - channel
-        - cloudbuild
-        - compute
-        - contact-center-insights
-        - container
-        - containeranalysis
-        - data-fusion
-        - datacatalog
-        - dataflow
-        - datalabeling
-        - dataproc
-        - dataproc-metastore
-        - datastore
-        - datastream
-        - debugger-client
-        - deploy
-        - dialogflow
-        - dialogflow-cx
-        - dlp
-        - dms
-        - dns
-        - document-ai
-        - domains
-        - errorreporting
-        - essential-contacts
-        - eventarc
-        - filestore
-        - firestore
-        - functions
-        - game-servers
-        - gke-connect-gateway
-        - gkehub
-        - gsuite-addons
-        - iam-admin
-        - iamcredentials
-        - iot
-        - kms
-        - language
-        - life-sciences
-        - logging
-        - logging-logback
-        - managed-identities
-        - mediatranslation
-        - memcache
-        - monitoring
-        - monitoring-dashboards
-        - network-management
-        - network-security
-        - networkconnectivity
-        - notebooks
-        - orchestration-airflow
-        - orgpolicy
-        - os-config
-        - os-login
-        - phishingprotection
-        - policy-troubleshooter
-        - private-catalog
-        - profiler
-        - pubsublite
-        - recaptchaenterprise
-        - recommendations-ai
-        - recommender
-        - redis
-        - resource-settings
-        - resourcemanager
-        - retail
-        - scheduler
-        - secretmanager
-        - security-private-ca
-        - securitycenter
-        - securitycenter-settings
-        - service-control
-        - service-management
-        - service-usage
-        - servicedirectory
-        - shell
-        - spanner
-        - spanner-jdbc
-        - speech
-        - storage
-        - storage-nio
-        - storage-transfer
-        - talent
-        - tasks
-        - texttospeech
-        - tpu
-        - trace
-        - translate
-        - video-intelligence
-        - video-transcoder
-        - vision
-        - vpcaccess
-        - webrisk
-        - websecurityscanner
-        - workflow-executions
-        - workflows
-    steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-java@v3
-      with:
-        distribution: zulu
-        java-version: ${{matrix.java}}
-    - run: java -version
-    - run: sudo apt-get update -y
-    - run: sudo apt-get install libxml2-utils
-    - run: .kokoro/downstream-client-library-check.sh ${{matrix.repo}} test
diff --git a/.github/workflows/sonar.yaml b/.github/workflows/sonar.yaml
deleted file mode 100644
index 1eb2608b8..000000000
--- a/.github/workflows/sonar.yaml
+++ /dev/null
@@ -1,38 +0,0 @@
-name: Sonar
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-    types: [opened, synchronize, reopened]
-jobs:
-  sonar-maven:
-    name: Java 11 Maven Build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
-      - name: Set up JDK 11
-        uses: actions/setup-java@v3
-        with:
-          distribution: temurin
-          java-version: 11
-      - name: Cache SonarCloud packages
-        uses: actions/cache@v3
-        with:
-          path: ~/.sonar/cache
-          key: ${{ runner.os }}-sonar
-          restore-keys: ${{ runner.os }}-sonar
-      - name: Cache Maven packages
-        uses: actions/cache@v3
-        with:
-          path: ~/.m2/repository
-          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
-          restore-keys: ${{ runner.os }}-m2
-      - name: Build and analyze
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Needed to get PR information, if any
-          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
-        run: mvn -B verify sonar:sonar -Dsonar.projectKey=googleapis_gax-java -Dsonar.organization=googleapis -Dsonar.host.url=https://sonarcloud.io
-
diff --git a/.gitignore b/.gitignore
deleted file mode 100644
index e6010998c..000000000
--- a/.gitignore
+++ /dev/null
@@ -1,24 +0,0 @@
-# Build results
-bin
-build
-.gradle
-tmp_docs
-bazel-*
-target
-
-# Eclipse
-.apt_generated*
-.classpath
-.factorypath
-.project
-.settings
-
-# IntelliJ
-.idea
-*.iml
-out
-
-# Vim.
-*.sw*
-*.vim
-
diff --git a/.kokoro/build.sh b/.kokoro/build.sh
deleted file mode 100755
index a9e909f0d..000000000
--- a/.kokoro/build.sh
+++ /dev/null
@@ -1,60 +0,0 @@
-#!/bin/bash
-# Copyright 2018 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -eo pipefail
-
-scriptDir=$(realpath $(dirname "${BASH_SOURCE[0]}"))
-# cd to the parent directory, i.e. the root of the git repo
-cd ${scriptDir}/..
-
-echo $JOB_TYPE
-
-function setJava() {
-  export JAVA_HOME=$1
-  export PATH=${JAVA_HOME}/bin:$PATH
-}
-
-# This project requires compiling the classes in JDK 11 or higher for GraalVM
-# classes. Compiling this project with Java 8 or earlier would fail with "class
-# file has wrong version 55.0, should be 53.0" and "unrecognized --release 8
-# option" (set in build.gradle).
-if [ ! -z "${JAVA11_HOME}" ]; then
-  setJava "${JAVA11_HOME}"
-fi
-
-mvn -V -B -ntp clean install -DskipTests
-
-# We ensure the generated class files are compatible with Java 8
-if [ ! -z "${JAVA8_HOME}" ]; then
-  setJava "${JAVA8_HOME}"
-fi
-
-RETURN_CODE=0
-
-case "${JOB_TYPE}" in
-test)
-  # run tests in Java 8 with the source compiled in Java 11
-  mvn -V -B -ntp surefire:test
-  RETURN_CODE=$?
-  ;;
-clirr)
-  mvn -B -ntp clirr:check
-  RETURN_CODE=$?
-  ;;
-*) ;;
-esac
-
-echo "exiting with ${RETURN_CODE}"
-exit ${RETURN_CODE}
\ No newline at end of file
diff --git a/.kokoro/common.cfg b/.kokoro/common.cfg
deleted file mode 100644
index e97bed17f..000000000
--- a/.kokoro/common.cfg
+++ /dev/null
@@ -1,13 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-# Download trampoline resources. These will be in ${KOKORO_GFILE_DIR}
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
-
-# All builds use the trampoline script to run in docker.
-build_file: "gax-java/.kokoro/trampoline.sh"
-
-# Tell the trampoline which build file to use.
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/gax-java/.kokoro/build.sh"
-}
diff --git a/.kokoro/downstream-client-library-check.sh b/.kokoro/downstream-client-library-check.sh
deleted file mode 100755
index 612fd793b..000000000
--- a/.kokoro/downstream-client-library-check.sh
+++ /dev/null
@@ -1,99 +0,0 @@
-#!/bin/bash
-# Copyright 2022 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -eo pipefail
-# Display commands being run.
-set -x
-
-CLIENT_LIBRARY=$1
-
-# Example JOB_TYPE: "test" or "graalvm"
-export JOB_TYPE=$2
-## Get the directory of the build script
-scriptDir="$(realpath "$(dirname "${BASH_SOURCE[0]}")")"
-## cd to the parent directory, i.e. the root of the git repo
-cd "${scriptDir}"/..
-
-# Round 1
-# Publish gax to local maven to make it available for downstream libraries
-./gradlew publishToMavenLocal
-
-# Read current gax version
-GAX_VERSION=$( ./gradlew -q :gax:properties | grep '^version: ' | cut -d' ' -f2 )
-
-# Round 2
-# Run this gax-java against HEAD of java-shared dependencies
-
-git clone "https://github.com/googleapis/java-shared-dependencies.git" --depth=1
-pushd java-shared-dependencies/first-party-dependencies
-
-# replace version
-xmllint --shell pom.xml << EOF
-setns x=http://maven.apache.org/POM/4.0.0
-cd .//x:artifactId[text()="gax-bom"]
-cd ../x:version
-set ${GAX_VERSION}
-cd ../..
-cd .//x:artifactId[text()="gax-grpc"]
-cd ../x:version
-set ${GAX_VERSION}
-save pom.xml
-EOF
-
-cd ..
-mvn verify install -B -V -ntp -fae \
--DskipTests=true \
--Dmaven.javadoc.skip=true \
--Dgcloud.download.skip=true \
--Denforcer.skip=true
-
-# Namespace (xmlns) prevents xmllint from specifying tag names in XPath
-SHARED_DEPS_VERSION=$( sed -e 's/xmlns=".*"//' pom.xml | xmllint --xpath '/project/version/text()' - )
-
-if [ -z "${SHARED_DEPS_VERSION}" ]; then
-  echo "Version is not found in pom.xml"
-  exit 1
-fi
-
-# Round 3
-# Run this shared-dependencies BOM against java client libraries
-git clone "https://github.com/googleapis/java-${CLIENT_LIBRARY}.git" --depth=1
-pushd java-"${CLIENT_LIBRARY}"
-
-if [[ $CLIENT_LIBRARY == "bigtable" ]]; then
-  pushd google-cloud-bigtable-deps-bom
-fi
-
-# replace version
-xmllint --shell pom.xml << EOF
-setns x=http://maven.apache.org/POM/4.0.0
-cd .//x:artifactId[text()="google-cloud-shared-dependencies"]
-cd ../x:version
-set ${SHARED_DEPS_VERSION}
-save pom.xml
-EOF
-
-if [[ $CLIENT_LIBRARY == "bigtable" ]]; then
-  popd
-fi
-
-echo "Modification on the shared dependencies BOM:"
-git diff
-echo
-
-export INTEGRATION_TEST_ARGS="-Denforcer.skip=true"
-
-# This reads the JOB_TYPE environmental variable ("test" or "graalvm")
-.kokoro/build.sh
diff --git a/.kokoro/populate-secrets.sh b/.kokoro/populate-secrets.sh
deleted file mode 100755
index f52514257..000000000
--- a/.kokoro/populate-secrets.sh
+++ /dev/null
@@ -1,43 +0,0 @@
-#!/bin/bash
-# Copyright 2020 Google LLC.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -eo pipefail
-
-function now { date +"%Y-%m-%d %H:%M:%S" | tr -d '\n' ;}
-function msg { println "$*" >&2 ;}
-function println { printf '%s\n' "$(now) $*" ;}
-
-
-# Populates requested secrets set in SECRET_MANAGER_KEYS from service account:
-# kokoro-trampoline@cloud-devrel-kokoro-resources.iam.gserviceaccount.com
-SECRET_LOCATION="${KOKORO_GFILE_DIR}/secret_manager"
-msg "Creating folder on disk for secrets: ${SECRET_LOCATION}"
-mkdir -p ${SECRET_LOCATION}
-for key in $(echo ${SECRET_MANAGER_KEYS} | sed "s/,/ /g")
-do
-  msg "Retrieving secret ${key}"
-  docker run --entrypoint=gcloud \
-    --volume=${KOKORO_GFILE_DIR}:${KOKORO_GFILE_DIR} \
-    gcr.io/google.com/cloudsdktool/cloud-sdk \
-    secrets versions access latest \
-    --project cloud-devrel-kokoro-resources \
-    --secret ${key} > \
-    "${SECRET_LOCATION}/${key}"
-  if [[ $? == 0 ]]; then
-    msg "Secret written to ${SECRET_LOCATION}/${key}"
-  else
-    msg "Error retrieving secret ${key}"
-  fi
-done
diff --git a/BUILD.bazel b/BUILD.bazel
deleted file mode 100644
index 2f08384e0..000000000
--- a/BUILD.bazel
+++ /dev/null
@@ -1,28 +0,0 @@
-load("//:gax_java.bzl", "google_java_format", "google_java_format_verification")
-
-exports_files(["dependencies.properties"])
-
-JAVA_COPTS = [
-    "-source",
-    "1.7",
-    "-target",
-    "1.7",
-]
-
-java_plugin(
-    name = "auto_value_plugin",
-    processor_class = "com.google.auto.value.processor.AutoValueProcessor",
-    deps = ["@com_google_auto_value_auto_value//jar"],
-    visibility = ["//visibility:public"],
-)
-
-# google-java-format
-java_binary(
-    name = "google_java_format_binary",
-    # Not letting the formatter consume too much memory (essential for CI builds)
-    jvm_flags = ["-Xmx512m"],
-    main_class = "com.google.googlejavaformat.java.Main",
-    visibility = ["//visibility:public"],
-    runtime_deps = ["@google_java_format_all_deps//jar"],
-)
-
diff --git a/CHANGELOG.md b/CHANGELOG.md
deleted file mode 100644
index dc948dcd8..000000000
--- a/CHANGELOG.md
+++ /dev/null
@@ -1,812 +0,0 @@
-# Changelog
-
-## [2.20.1](https://github.com/googleapis/gax-java/compare/v2.20.0...v2.20.1) (2022-12-02)
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.api.grpc:grpc-google-common-protos to v2.11.0 ([#1906](https://github.com/googleapis/gax-java/issues/1906)) ([d27d848](https://github.com/googleapis/gax-java/commit/d27d8485d3da4de00253c1f5df435516d1af8d8e))
-* **deps:** Update dependency com.google.api.grpc:proto-google-common-protos to v2.11.0 ([#1907](https://github.com/googleapis/gax-java/issues/1907)) ([7504e37](https://github.com/googleapis/gax-java/commit/7504e37163d39d10bd8388101e9ce614e2839aca))
-* **deps:** Update dependency com.google.cloud:google-cloud-shared-config to v1.5.5 ([#1911](https://github.com/googleapis/gax-java/issues/1911)) ([772c221](https://github.com/googleapis/gax-java/commit/772c2213dfa10120b6efccf411550e77df3f9de7))
-* **deps:** Update dependency com.google.protobuf:protobuf-bom to v3.21.10 ([#1912](https://github.com/googleapis/gax-java/issues/1912)) ([f508f24](https://github.com/googleapis/gax-java/commit/f508f245a59b2086c4b56d55f0cb25e9e7c29136))
-* Watchdog controls lifecycle of the future, not executor ([#1890](https://github.com/googleapis/gax-java/issues/1890)) ([bd1714e](https://github.com/googleapis/gax-java/commit/bd1714e484eef8aa8f09632eee976c9da26da5f1))
-
-## [2.20.0](https://github.com/googleapis/gax-java/compare/v2.19.5...v2.20.0) (2022-11-30)
-
-
-### Features
-
-* De-experiment google-c2p resolver ([#1896](https://github.com/googleapis/gax-java/issues/1896)) ([66b348b](https://github.com/googleapis/gax-java/commit/66b348b9fd817e0986c67eb02e0609646fb822b3))
-* Next release from main branch is 2.20.0 ([#1867](https://github.com/googleapis/gax-java/issues/1867)) ([c7aeed3](https://github.com/googleapis/gax-java/commit/c7aeed3362352b77f86749e86ccebd1d1390de48))
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.auth:google-auth-library-credentials to v1.13.0 ([#1881](https://github.com/googleapis/gax-java/issues/1881)) ([d059db7](https://github.com/googleapis/gax-java/commit/d059db7131c6866c9782c0c3ac39b980b13911df))
-* **deps:** Update dependency com.google.auth:google-auth-library-oauth2-http to v1.13.0 ([#1882](https://github.com/googleapis/gax-java/issues/1882)) ([67af68a](https://github.com/googleapis/gax-java/commit/67af68a02198360dad2941eefa9897628342ee60))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.51.0 ([#1889](https://github.com/googleapis/gax-java/issues/1889)) ([85af72c](https://github.com/googleapis/gax-java/commit/85af72c4159a416e7026cf47a0d8e4fc5ef23be0))
-* **deps:** Update dependency org.mockito:mockito-core to v4.9.0 ([#1879](https://github.com/googleapis/gax-java/issues/1879)) ([9505cb1](https://github.com/googleapis/gax-java/commit/9505cb1d89de8f6fc47f5f4a7a083129b4ffc58d))
-
-## [2.19.5](https://github.com/googleapis/gax-java/compare/v2.19.4...v2.19.5) (2022-11-07)
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.cloud:google-cloud-shared-config to v1.5.4 ([#1840](https://github.com/googleapis/gax-java/issues/1840)) ([8f7a38c](https://github.com/googleapis/gax-java/commit/8f7a38ca0a9d187af49649adf7d96ef97c9e9915))
-* **deps:** Update dependency com.google.code.gson:gson to v2.10 ([#1845](https://github.com/googleapis/gax-java/issues/1845)) ([816e666](https://github.com/googleapis/gax-java/commit/816e6665e06bc65cbaf2703617342c8db9780115))
-* **deps:** Update dependency com.google.protobuf:protobuf-bom to v3.21.9 ([#1850](https://github.com/googleapis/gax-java/issues/1850)) ([f270ac4](https://github.com/googleapis/gax-java/commit/f270ac45b6a21d531eb8bd75157f2784fcad90fc))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.50.2 ([#1842](https://github.com/googleapis/gax-java/issues/1842)) ([11c4a7c](https://github.com/googleapis/gax-java/commit/11c4a7caf31de256f29678de829f11f9558adcfd))
-* **deps:** Update dependency org.mockito:mockito-core to v4.8.1 ([#1843](https://github.com/googleapis/gax-java/issues/1843)) ([bf67fc2](https://github.com/googleapis/gax-java/commit/bf67fc26236286d72b9ddcb2e66113fdac74b51a))
-* **deps:** Update dependency org.threeten:threetenbp to v1.6.4 ([#1857](https://github.com/googleapis/gax-java/issues/1857)) ([a9e2374](https://github.com/googleapis/gax-java/commit/a9e23744a40f6e5484f1834824515f8ae952873c))
-
-
-### Dependencies
-
-* update dependency com.google.api:api-common to 2.2.2 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* update dependency com.google.api.grpc:grpc-google-common-protos to 2.10.0 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* Update dependency com.google.api.grpc:proto-google-common-protos to 2.10.0 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* update dependency com.google.auth:google-auth-library-credentials to 1.12.1 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* update dependency com.google.auth:google-auth-library-oauth2-http to 1.12.1 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* update dependency com.google.http-client:google-http-client to 1.42.3 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-* update dependency com.google.http-client:google-http-client-gson to 1.42.3 ([ad7ad1c](https://github.com/googleapis/gax-java/commit/ad7ad1c5b450cd0569ff34d3b553dd1493fa462c))
-
-## [2.19.4](https://github.com/googleapis/gax-java/compare/v2.19.3...v2.19.4) (2022-10-19)
-
-
-### Bug Fixes
-
-* Scope the throttling metric to exclude element size calculation ([#1835](https://github.com/googleapis/gax-java/issues/1835)) ([0287f83](https://github.com/googleapis/gax-java/commit/0287f83f9cabbb9dff6cb7e8ea3068ccc1ab12d9))
-
-## [2.19.3](https://github.com/googleapis/gax-java/compare/v2.19.2...v2.19.3) (2022-10-19)
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.auth:google-auth-library-credentials to v1.12.0 ([#1822](https://github.com/googleapis/gax-java/issues/1822)) ([ad139e4](https://github.com/googleapis/gax-java/commit/ad139e45d29bd0fbf6b6f080b12ef9a987fa2e0d))
-* **deps:** Update dependency com.google.auth:google-auth-library-credentials to v1.12.1 ([#1830](https://github.com/googleapis/gax-java/issues/1830)) ([d726921](https://github.com/googleapis/gax-java/commit/d7269210767a92e94568712920b34064278dddbc))
-* **deps:** Update dependency com.google.auth:google-auth-library-oauth2-http to v1.12.0 ([#1823](https://github.com/googleapis/gax-java/issues/1823)) ([c6180ca](https://github.com/googleapis/gax-java/commit/c6180cacdaf4d191098e499eff0f6b014e730654))
-* **deps:** Update dependency com.google.auth:google-auth-library-oauth2-http to v1.12.1 ([#1831](https://github.com/googleapis/gax-java/issues/1831)) ([227c8af](https://github.com/googleapis/gax-java/commit/227c8af66c95e86e8d90e5de9dd3f429895b44cc))
-* **deps:** Update dependency com.google.protobuf:protobuf-bom to v3.21.8 ([#1828](https://github.com/googleapis/gax-java/issues/1828)) ([462a100](https://github.com/googleapis/gax-java/commit/462a1009a84a046da28298ad10f23cadfb7a61ea))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.50.1 ([#1819](https://github.com/googleapis/gax-java/issues/1819)) ([75600ea](https://github.com/googleapis/gax-java/commit/75600eab90ec2e33378c00824535763f5df87b24))
-* **deps:** Update dependency org.graalvm.sdk:graal-sdk to v22.2.0.1 ([#1817](https://github.com/googleapis/gax-java/issues/1817)) ([a8f8ae2](https://github.com/googleapis/gax-java/commit/a8f8ae2b5e035dc08ce161134ec2e441e6c2d4fc))
-* **deps:** Update dependency org.threeten:threetenbp to v1.6.3 ([#1821](https://github.com/googleapis/gax-java/issues/1821)) ([3bca572](https://github.com/googleapis/gax-java/commit/3bca572486e7780ff8fb8b581aa691738885401c))
-* **java:** Address ClassNotFoundException in GraalVM 22.2.0 ([#1816](https://github.com/googleapis/gax-java/issues/1816)) ([ae6e8be](https://github.com/googleapis/gax-java/commit/ae6e8beb6ed5525504df1a3bb7ce71bdf114a233))
-* **java:** Address reachability issues in native image compilation with version 22.2.0 ([#1815](https://github.com/googleapis/gax-java/issues/1815)) ([0f3215f](https://github.com/googleapis/gax-java/commit/0f3215f98bfc5def4e608c780d91953900e17946))
-
-## [2.19.2](https://github.com/googleapis/gax-java/compare/v2.19.1...v2.19.2) (2022-10-02)
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.3 ([#1797](https://github.com/googleapis/gax-java/issues/1797)) ([50c6a75](https://github.com/googleapis/gax-java/commit/50c6a75db05537b873d0d143fdccab82f46bc644))
-* **deps:** Update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.4 ([#1800](https://github.com/googleapis/gax-java/issues/1800)) ([6d4e62d](https://github.com/googleapis/gax-java/commit/6d4e62de5c2303d7c31faa046966b8842cbcfe53))
-* **deps:** Update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.5 ([#1805](https://github.com/googleapis/gax-java/issues/1805)) ([1f9fe38](https://github.com/googleapis/gax-java/commit/1f9fe38e3b152dad50a026adea8ea9b488acf786))
-* **deps:** Update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.6 ([#1810](https://github.com/googleapis/gax-java/issues/1810)) ([a206f46](https://github.com/googleapis/gax-java/commit/a206f46a095812c77cce1085a546692ba871deef))
-* **deps:** Update dependency com.google.api.grpc:proto-google-common-protos to v2.9.3 ([#1798](https://github.com/googleapis/gax-java/issues/1798)) ([8a1c732](https://github.com/googleapis/gax-java/commit/8a1c732bf938818a40c907b5656025cac52b9645))
-* **deps:** Update dependency com.google.api.grpc:proto-google-common-protos to v2.9.4 ([#1801](https://github.com/googleapis/gax-java/issues/1801)) ([0e2a405](https://github.com/googleapis/gax-java/commit/0e2a4053d945f4d4da55f8b5486df6dbcab66c2f))
-* **deps:** Update dependency com.google.api.grpc:proto-google-common-protos to v2.9.5 ([#1806](https://github.com/googleapis/gax-java/issues/1806)) ([da9dff8](https://github.com/googleapis/gax-java/commit/da9dff8a9cd2db63b396df42830c679b3555187d))
-* **deps:** Update dependency com.google.api.grpc:proto-google-common-protos to v2.9.6 ([#1811](https://github.com/googleapis/gax-java/issues/1811)) ([bb5dffa](https://github.com/googleapis/gax-java/commit/bb5dffa51de48a6f97304a50c4a596e21673bb6e))
-* **deps:** Update dependency com.google.protobuf:protobuf-bom to v3.21.6 ([#1792](https://github.com/googleapis/gax-java/issues/1792)) ([d94482e](https://github.com/googleapis/gax-java/commit/d94482ef19f45b6dfbe775d7facf3467b09cb194))
-* **deps:** Update dependency com.google.protobuf:protobuf-bom to v3.21.7 ([#1803](https://github.com/googleapis/gax-java/issues/1803)) ([534250b](https://github.com/googleapis/gax-java/commit/534250bdb165576bea7793a61b39c11312e4ec31))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.49.1 ([#1796](https://github.com/googleapis/gax-java/issues/1796)) ([9cb8d36](https://github.com/googleapis/gax-java/commit/9cb8d3640ff40f30f8dae2efd7341578fd449a7d))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.49.2 ([#1808](https://github.com/googleapis/gax-java/issues/1808)) ([b27f15d](https://github.com/googleapis/gax-java/commit/b27f15d277f74bc11e10e6e25b588b1767f8e5ee))
-* **deps:** Update dependency org.threeten:threetenbp to v1.6.2 ([#1799](https://github.com/googleapis/gax-java/issues/1799)) ([6a45067](https://github.com/googleapis/gax-java/commit/6a450679302c611960710f5a98e32d278bda2b60))
-* remove --allow-incomplete-classpath which has been deprecated as of Graalvm 22.1.0 ([e5c739c](https://github.com/googleapis/gax-java/commit/e5c739c093067f6f2340f873ed96dfea8ef9b7d6))
-* Remove --allow-incomplete-classpath which was deprecated as of Graalvm 22.1.0 ([#1794](https://github.com/googleapis/gax-java/issues/1794)) ([e5c739c](https://github.com/googleapis/gax-java/commit/e5c739c093067f6f2340f873ed96dfea8ef9b7d6))
-
-## [2.19.1](https://github.com/googleapis/gax-java/compare/v2.19.0...v2.19.1) (2022-09-13)
-
-
-### Bug Fixes
-
-* **deps:** Update dependency com.google.auth:google-auth-library-credentials to v1.11.0 ([#1786](https://github.com/googleapis/gax-java/issues/1786)) ([4889ff7](https://github.com/googleapis/gax-java/commit/4889ff7ccd3ae13052c4b7009ce81bcd88d650a9))
-* **deps:** Update dependency com.google.auth:google-auth-library-oauth2-http to v1.11.0 ([#1787](https://github.com/googleapis/gax-java/issues/1787)) ([4f5cd42](https://github.com/googleapis/gax-java/commit/4f5cd428f416e7d43f3268de32e5314ac3317460))
-* **deps:** Update dependency io.grpc:grpc-bom to v1.49.0 ([#1779](https://github.com/googleapis/gax-java/issues/1779)) ([037e131](https://github.com/googleapis/gax-java/commit/037e131ad46690f6d1badb45dc2f31ca981c1348))
-* **deps:** Update dependency org.mockito:mockito-core to v4.8.0 ([#1785](https://github.com/googleapis/gax-java/issues/1785)) ([f2989bd](https://github.com/googleapis/gax-java/commit/f2989bd706e7b3c524d2f0b8ceaa1d576dd7f751))
-* **httpjson:** Handle message derived query params ([#1784](https://github.com/googleapis/gax-java/issues/1784)) ([4524fad](https://github.com/googleapis/gax-java/commit/4524fadbe688d96a7c5e715ab88b542b4bb3891a))
-
-## [2.19.0](https://github.com/googleapis/gax-java/compare/v2.18.7...v2.19.0) (2022-08-22)
-
-
-### Features
-
-* Add numeric enum support. ([#1743](https://github.com/googleapis/gax-java/issues/1743)) ([3f7628e](https://github.com/googleapis/gax-java/commit/3f7628e27495806675ec8c8521e9c33725908936))
-
-
-### Bug Fixes
-
-* **deps:** update dependency com.google.auth:google-auth-library-credentials to v1.10.0 ([#1768](https://github.com/googleapis/gax-java/issues/1768)) ([3f2188d](https://github.com/googleapis/gax-java/commit/3f2188d83751272de1a4c3db85e95d79b690e3fc))
-* **deps:** update dependency com.google.auth:google-auth-library-credentials to v1.9.0 ([#1765](https://github.com/googleapis/gax-java/issues/1765)) ([103db3c](https://github.com/googleapis/gax-java/commit/103db3cc06cfaafeda1a043b6e19e668083ed782))
-* **deps:** update dependency com.google.auth:google-auth-library-oauth2-http to v1.10.0 ([#1769](https://github.com/googleapis/gax-java/issues/1769)) ([0b1eb92](https://github.com/googleapis/gax-java/commit/0b1eb924aefc79b6fc4757d253d4c8a93a094c84))
-* **deps:** update dependency com.google.auth:google-auth-library-oauth2-http to v1.9.0 ([#1766](https://github.com/googleapis/gax-java/issues/1766)) ([2677f07](https://github.com/googleapis/gax-java/commit/2677f07a8e20c82403f60c6aa1f9d46c1274b37f))
-* **deps:** update dependency com.google.code.gson:gson to v2.9.1 ([#1757](https://github.com/googleapis/gax-java/issues/1757)) ([ea2a075](https://github.com/googleapis/gax-java/commit/ea2a07504899703e4fcd428f31d615fb208a50aa))
-* **deps:** update dependency com.google.protobuf:protobuf-bom to v3.21.5 ([#1772](https://github.com/googleapis/gax-java/issues/1772)) ([d7a48d1](https://github.com/googleapis/gax-java/commit/d7a48d1886a3f39acb26580d1d35a288102af436))
-* **deps:** update dependency io.grpc:grpc-bom to v1.48.1 ([#1763](https://github.com/googleapis/gax-java/issues/1763)) ([e5e4232](https://github.com/googleapis/gax-java/commit/e5e423200260c210071ce626612d7e54af0695e4))
-* **deps:** update dependency org.graalvm.sdk:graal-sdk to v22.2.0 ([#1740](https://github.com/googleapis/gax-java/issues/1740)) ([ded44a6](https://github.com/googleapis/gax-java/commit/ded44a66d3de8a2678fa4c5efe8b3ded4484de2b))
-* **deps:** update dependency org.mockito:mockito-core to v4.7.0 ([#1774](https://github.com/googleapis/gax-java/issues/1774)) ([29678c8](https://github.com/googleapis/gax-java/commit/29678c805855c97b4c26f0156923a41820411a10))
-* **deps:** update dependency org.threeten:threetenbp to v1.6.1 ([#1773](https://github.com/googleapis/gax-java/issues/1773)) ([d2c84e6](https://github.com/googleapis/gax-java/commit/d2c84e6fb22a2752b68fecc9b6c9e480f398b87c))
-* **test:** testThrottlingBlocking flakyness fix ([#1775](https://github.com/googleapis/gax-java/issues/1775)) ([e69393c](https://github.com/googleapis/gax-java/commit/e69393c32ffe32306acc8f495b1f41198d86f507))
-
-
-### Documentation
-
-* explaining UNIX environment is required ([#1760](https://github.com/googleapis/gax-java/issues/1760)) ([1d31e90](https://github.com/googleapis/gax-java/commit/1d31e90e70867cb4b896d7a393f9271788b6371f))
-
-## [2.18.7](https://github.com/googleapis/gax-java/compare/v2.18.6...v2.18.7) (2022-08-01)
-
-
-### Bug Fixes
-
-* **java:** initialize netty class at run time ([#1758](https://github.com/googleapis/gax-java/issues/1758)) ([e1d6eb9](https://github.com/googleapis/gax-java/commit/e1d6eb979da21e9795b3c3d2fffb9200ee43ed15))
-
-## [2.18.6](https://github.com/googleapis/gax-java/compare/v2.18.5...v2.18.6) (2022-07-29)
-
-
-### Bug Fixes
-
-* **deps:** update dependency com.google.cloud:google-cloud-shared-config to v1.5.2 ([#1746](https://github.com/googleapis/gax-java/issues/1746)) ([8163f8a](https://github.com/googleapis/gax-java/commit/8163f8aa822881d8cd6f1f72aca66b50fbd2e66a))
-* **deps:** update dependency com.google.cloud:google-cloud-shared-config to v1.5.3 ([#1748](https://github.com/googleapis/gax-java/issues/1748)) ([f2b7cb2](https://github.com/googleapis/gax-java/commit/f2b7cb2b6b783095547b798da054b6879d3764f1))
-* **deps:** update dependency com.google.protobuf:protobuf-bom to v3.21.4 ([#1747](https://github.com/googleapis/gax-java/issues/1747)) ([0b2b1ef](https://github.com/googleapis/gax-java/commit/0b2b1efcf38ff9f253e426af8c21722d646c8627))
-* Exclude error_prone_annotations from guava. ([#1750](https://github.com/googleapis/gax-java/issues/1750)) ([e1c91a4](https://github.com/googleapis/gax-java/commit/e1c91a40bcf413af5210da1d43e409d44dcf13bd))
-
-## [2.18.5](https://github.com/googleapis/gax-java/compare/v2.18.4...v2.18.5) (2022-07-25)
-
-
-### Bug Fixes
-
-* **deps:** update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.2 ([#1735](https://github.com/googleapis/gax-java/issues/1735)) ([d7f00be](https://github.com/googleapis/gax-java/commit/d7f00beae84c093a732982aaeedd7d6a8752e52c))
-* **deps:** update dependency com.google.api.grpc:proto-google-common-protos to v2.9.2 ([#1736](https://github.com/googleapis/gax-java/issues/1736)) ([ee3d4ad](https://github.com/googleapis/gax-java/commit/ee3d4ad29a84da9113790dd03b8f0bbd89625a7c))
-* **deps:** update dependency com.google.auth:google-auth-library-credentials to v1.8.1 ([#1737](https://github.com/googleapis/gax-java/issues/1737)) ([24bc629](https://github.com/googleapis/gax-java/commit/24bc629aa1ffc0513ba766858935ead7ab18bf9e))
-* **deps:** update dependency com.google.auth:google-auth-library-oauth2-http to v1.8.1 ([#1738](https://github.com/googleapis/gax-java/issues/1738)) ([1030eb6](https://github.com/googleapis/gax-java/commit/1030eb6b1df5008f304d0989fd991f88f148cc2a))
-* **deps:** update dependency com.google.cloud:google-cloud-shared-config to v1.5.1 ([#1726](https://github.com/googleapis/gax-java/issues/1726)) ([bdffb86](https://github.com/googleapis/gax-java/commit/bdffb86c05235c4ad783ab7afd28724386465569))
-* **deps:** update dependency com.google.http-client:google-http-client-bom to v1.42.2 ([#1727](https://github.com/googleapis/gax-java/issues/1727)) ([030e9b3](https://github.com/googleapis/gax-java/commit/030e9b33ec6bd98122fba59a1bc39513444c3511))
-* **deps:** update dependency com.google.protobuf:protobuf-bom to v3.21.3 ([#1742](https://github.com/googleapis/gax-java/issues/1742)) ([9215e1f](https://github.com/googleapis/gax-java/commit/9215e1f58ebcc6eccef42c53981ab90865fe366a))
-* **deps:** update dependency io.grpc:grpc-bom to v1.48.0 ([#1741](https://github.com/googleapis/gax-java/issues/1741)) ([4735a4b](https://github.com/googleapis/gax-java/commit/4735a4b29b686ba510a25ad8458142870e50b1c5))
-* remove initialization of logger classes which is conflicting with slf4j ([#1733](https://github.com/googleapis/gax-java/issues/1733)) ([ccaf265](https://github.com/googleapis/gax-java/commit/ccaf26537a189dacb9b3bb58760a4c6f6cd48a87))
-
-## [2.18.4](https://github.com/googleapis/gax-java/compare/v2.18.3...v2.18.4) (2022-07-11)
-
-
-### Bug Fixes
-
-* Build routing header params map with the last entry if multiple entries have the same key. ([#1729](https://github.com/googleapis/gax-java/issues/1729)) ([878bcf2](https://github.com/googleapis/gax-java/commit/878bcf2da215e14d9e3bcb4717b85d867f149cee))
-* **deps:** update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.1 ([#1721](https://github.com/googleapis/gax-java/issues/1721)) ([bef0af7](https://github.com/googleapis/gax-java/commit/bef0af71b4d1923980fe7a64cf1ac4435463e2db))
-* **deps:** update dependency com.google.api.grpc:proto-google-common-protos to v2.9.1 ([#1722](https://github.com/googleapis/gax-java/issues/1722)) ([7034ead](https://github.com/googleapis/gax-java/commit/7034ead57d990b8e2382ff015ba47fc97cdf271b))
-* **deps:** update dependency com.google.auth:google-auth-library-credentials to v1.8.0 ([#1723](https://github.com/googleapis/gax-java/issues/1723)) ([b062d6d](https://github.com/googleapis/gax-java/commit/b062d6d861fa7162f0f9e8287c988802e4a194c5))
-* **deps:** update dependency com.google.auth:google-auth-library-oauth2-http to v1.8.0 ([#1724](https://github.com/googleapis/gax-java/issues/1724)) ([bd8ee04](https://github.com/googleapis/gax-java/commit/bd8ee04f202b7faa7f13ccb868e574055ffb3c88))
-
-## [2.18.3](https://github.com/googleapis/gax-java/compare/v2.18.2...v2.18.3) (2022-06-27)
-
-
-### Bug Fixes
-
-* **deps:** update dependency com.google.api.grpc:grpc-google-common-protos to v2.9.0 ([#1706](https://github.com/googleapis/gax-java/issues/1706)) ([eb195c0](https://github.com/googleapis/gax-java/commit/eb195c000b19472fc15a2586320f4421b6ee92a3))
-* **deps:** update dependency com.google.api.grpc:proto-google-common-protos to v2.9.0 ([#1708](https://github.com/googleapis/gax-java/issues/1708)) ([0a606f5](https://github.com/googleapis/gax-java/commit/0a606f5d6f40a44b153f186d824e3a731586bb49))
-* **deps:** update dependency com.google.cloud:google-cloud-shared-config to v1.5.0 ([#1711](https://github.com/googleapis/gax-java/issues/1711)) ([eb11bb0](https://github.com/googleapis/gax-java/commit/eb11bb027cde3e4abc8049a04056907de79386ab))
-* **deps:** update dependency com.google.protobuf:protobuf-bom to v3.21.2 ([#1720](https://github.com/googleapis/gax-java/issues/1720)) ([19a38cf](https://github.com/googleapis/gax-java/commit/19a38cffd13fbaa547a9992f61689d70239b6ee4))
-* **deps:** update dependency org.mockito:mockito-core to v4.6.1 ([#1705](https://github.com/googleapis/gax-java/issues/1705)) ([7befaa4](https://github.com/googleapis/gax-java/commit/7befaa4a2525f9b09091225b2f74a3e2fbfa3175))
-* **deps:** update dependency org.threeten:threetenbp to v1.6.0 ([#1709](https://github.com/googleapis/gax-java/issues/1709)) ([42cdcaa](https://github.com/googleapis/gax-java/commit/42cdcaa5a5d2362e86f94a13870f3c9c48f8b7f7))
-
-## [2.18.2](https://github.com/googleapis/gax-java/compare/v2.18.1...v2.18.2) (2022-06-16)
-
-
-### Bug Fixes
-
-* **deps:** update dependency com.google.api:api-common to v2.2.1 ([#1699](https://github.com/googleapis/gax-java/issues/1699)) ([be79d10](https://github.com/googleapis/gax-java/commit/be79d108601290d533126e996600a5864a7e810f))
-* **deps:** update dependency com.google.auth:google-auth-library-credentials to v1.7.0 ([#1700](https://github.com/googleapis/gax-java/issues/1700)) ([640525e](https://github.com/googleapis/gax-java/commit/640525ea4d2df46c187f867f7c13325aebd819c6))
-* **deps:** update dependency com.google.auth:google-auth-library-oauth2-http to v1.7.0 ([#1701](https://github.com/googleapis/gax-java/issues/1701)) ([0f27ef7](https://github.com/googleapis/gax-java/commit/0f27ef7b63aa37fd7797e43803802a519d710658))
-* **deps:** update dependency com.google.http-client:google-http-client-bom to v1.42.0 ([#1702](https://github.com/googleapis/gax-java/issues/1702)) ([96c4fa8](https://github.com/googleapis/gax-java/commit/96c4fa8b76e485fb6e19b183c11d660bd949c6c2))
-* **deps:** update dependency com.google.protobuf:protobuf-bom to v3.21.1 ([#1703](https://github.com/googleapis/gax-java/issues/1703)) ([3e07036](https://github.com/googleapis/gax-java/commit/3e07036bba7c6945c76a76cd623726c71d74ade2))
-* **deps:** update dependency io.grpc:grpc-bom to v1.47.0 ([#1704](https://github.com/googleapis/gax-java/issues/1704)) ([0317926](https://github.com/googleapis/gax-java/commit/0317926ea97940df73738d1617e0b154e70b7e32))
-* **deps:** update dependency io.opencensus:opencensus-api to v0.31.1 ([#1697](https://github.com/googleapis/gax-java/issues/1697)) ([f9f9e1e](https://github.com/googleapis/gax-java/commit/f9f9e1e2a16532c3051595138bc2e99c71268f3a))
-* **deps:** update dependency org.graalvm.sdk:graal-sdk to v22.1.0.1 ([#1698](https://github.com/googleapis/gax-java/issues/1698)) ([59fbff9](https://github.com/googleapis/gax-java/commit/59fbff938981be18134c1410c02d86dbf801f4a7))
-
-
-### Dependencies
-
-* update dependency com.google.api.grpc:proto-google-common-protos to v2.9.0 ([#1713](https://github.com/googleapis/gax-java/issues/1713)) ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update dependency io.grpc:grpc-bom to v1.47.0 ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update dependency io.opencensus:opencensus-api to v0.31.1 ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update dependency org.mockito:mockito-core to v4.6.1 ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update dependency org.threeten:threetenbp to v1.6.0 ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update io.netty dependencies to v4.1.72.Final ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-* update plugin org.sonarqube to v3.4.0.2513 ([c5eb06e](https://github.com/googleapis/gax-java/commit/c5eb06eec5d2cde85d37b096418e873c1bd83470))
-
-### [2.18.1](https://github.com/googleapis/gax-java/compare/v2.18.0...v2.18.1) (2022-05-19)
-
-
-### Dependencies
-
-* upgrade grpc to 1.46.0 ([#1688](https://github.com/googleapis/gax-java/issues/1688)) ([18147a4](https://github.com/googleapis/gax-java/commit/18147a4f558635b27d30eb05468321b52321db13))
-
-## [2.18.0](https://github.com/googleapis/gax-java/compare/v2.17.0...v2.18.0) (2022-05-18)
-
-
-### Features
-
-* [REGAPIC] Add support for additional bindings ([#1680](https://github.com/googleapis/gax-java/issues/1680)) ([59b3699](https://github.com/googleapis/gax-java/commit/59b3699b6acbc98c55dc043bf8665b457a0615a9))
-* upgrade graal-sdk to 22.1.0 ([#1683](https://github.com/googleapis/gax-java/issues/1683)) ([46f899d](https://github.com/googleapis/gax-java/commit/46f899de06e60a792f5a6c1dc617673f0f180c00))
-
-
-### Bug Fixes
-
-* **java:** remove conflicting reflection configuration to address UnsupportedFeatureException with GraalVM 22.1.0 ([#1682](https://github.com/googleapis/gax-java/issues/1682)) ([97c6c8b](https://github.com/googleapis/gax-java/commit/97c6c8bfa0d5397e30d3699e92f823e09ee283e6))
-* remove svm dependency ([#1679](https://github.com/googleapis/gax-java/issues/1679)) ([c1b88e3](https://github.com/googleapis/gax-java/commit/c1b88e3788ab866bcc1ba3db94c2998198a0b35e))
-
-
-### Dependencies
-
-* update dependency com.google.api:api-common to 2.2.0 ([#1685](https://github.com/googleapis/gax-java/issues/1685)) ([a5a316b](https://github.com/googleapis/gax-java/commit/a5a316bde322733eb5a80093206eb12b36945580))
-
-## [2.17.0](https://github.com/googleapis/gax-java/compare/v2.16.0...v2.17.0) (2022-05-10)
-
-
-### Features
-
-* next release from main branch is 2.17.0 ([#1659](https://github.com/googleapis/gax-java/issues/1659)) ([5a31361](https://github.com/googleapis/gax-java/commit/5a3136121bc8365a798aa2f5c363e86de6224391))
-
-
-### Bug Fixes
-
-* Fix handling of null responses in rest transport ([#1668](https://github.com/googleapis/gax-java/issues/1668)) ([8def947](https://github.com/googleapis/gax-java/commit/8def947620610b7aab526413a1ac14fd4f890dbf))
-* use graal-sdk 21.3.2 ([#1670](https://github.com/googleapis/gax-java/issues/1670)) ([92c2697](https://github.com/googleapis/gax-java/commit/92c2697b211b2aa9e5456dbb1078870a30f0703a))
-
-## [2.16.0](https://github.com/googleapis/gax-java/compare/v2.15.0...v2.16.0) (2022-04-14)
-
-
-### Features
-
-* relocate ApiClientSubstitutions from java-core to gax ([#1651](https://github.com/googleapis/gax-java/issues/1651)) ([321103f](https://github.com/googleapis/gax-java/commit/321103f129cb1ece3f3a4d62e3c050c975d33179))
-* relocate GoogleJsonClientFeature from java-core to gax ([#1655](https://github.com/googleapis/gax-java/issues/1655)) ([6e75ec7](https://github.com/googleapis/gax-java/commit/6e75ec76f2bf448eb56f644e61019efb3940a388))
-* relocate netty and gax substitutions from java-core ([#1650](https://github.com/googleapis/gax-java/issues/1650)) ([afd1917](https://github.com/googleapis/gax-java/commit/afd19177c44c9cd0a982e545e4b0e60c0313d6f4))
-* relocate Opencensus configurations from java-core to gax ([#1646](https://github.com/googleapis/gax-java/issues/1646)) ([b34ffb1](https://github.com/googleapis/gax-java/commit/b34ffb1fb2af6b18a4272dcc951b2f4294c75317))
-* relocate resource-config from java-core to gax ([#1656](https://github.com/googleapis/gax-java/issues/1656)) ([a9e5483](https://github.com/googleapis/gax-java/commit/a9e5483d5b67e080d1a8b012f0a3fb4ca8aadf18))
-
-
-### Dependencies
-
-* google-common-protos 2.8.3 ([#1657](https://github.com/googleapis/gax-java/issues/1657)) ([24b9138](https://github.com/googleapis/gax-java/commit/24b9138cc8088c2124f6d9e2ebc8ddc88a08fd9e))
-
-## [2.15.0](https://github.com/googleapis/gax-java/compare/v2.14.0...v2.15.0) (2022-04-06)
-
-
-### Features
-
-* Error Details Improvements - GRPC ([#1634](https://github.com/googleapis/gax-java/issues/1634)) ([00c3b9d](https://github.com/googleapis/gax-java/commit/00c3b9ddae11736e1231e4aa45965deff7689f2a))
-* relocate native image properties from java-core to gax ([#1648](https://github.com/googleapis/gax-java/issues/1648)) ([609c2aa](https://github.com/googleapis/gax-java/commit/609c2aab94ff215c879932e60ae041309f20c2c7))
-
-
-### Dependencies
-
-* upgrade grpc to 1.45.1 and auth to 1.6.0 ([#1652](https://github.com/googleapis/gax-java/issues/1652)) ([8f8f625](https://github.com/googleapis/gax-java/commit/8f8f62572795c83b4459f6d3a0f33f31a1ecfb71))
-
-## [2.14.0](https://github.com/googleapis/gax-java/compare/v2.13.0...v2.14.0) (2022-04-01)
-
-
-### Features
-
-* relocate Netty Native Image configurations from java-core to gax ([#1638](https://github.com/googleapis/gax-java/issues/1638)) ([aafded4](https://github.com/googleapis/gax-java/commit/aafded4a0b779c68d0d5702b722672a0f86ccdd1))
-* relocate protobuf configurations from java-core to gax-java ([#1641](https://github.com/googleapis/gax-java/issues/1641)) ([01d395f](https://github.com/googleapis/gax-java/commit/01d395f486ccd7c364c03ccdfcfbf83b900192c3))
-
-
-### Bug Fixes
-
-* update the runtime dependency grpc-java xds to googleapis ([#1643](https://github.com/googleapis/gax-java/issues/1643)) ([b8d9e30](https://github.com/googleapis/gax-java/commit/b8d9e30c3e2209bcd4cc0f808dfdf0a0608aa466))
-
-## [2.13.0](https://github.com/googleapis/gax-java/compare/v2.12.2...v2.13.0) (2022-03-25)
-
-
-### Features
-
-* dynamic channel pool scaled by number of outstanding request ([#1569](https://github.com/googleapis/gax-java/issues/1569)) ([fff2bab](https://github.com/googleapis/gax-java/commit/fff2babaf2620686c2e0be1b6d338ac088248cf6))
-
-
-### Dependencies
-
-* update dependency com_google_protobuf to 3.19.4 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.api:api-common to 2.1.5 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.api.grpc:grpc-google-common-protos to 2.8.0 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.api.grpc:proto-google-common-protos to 2.8.0 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.guava:guava to 31.1-jre ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.http-client:google-http-client to 1.41.5 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency com.google.http-client:google-http-client-gson to 1.41.5 ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-* update dependency io_grpc to 1.45.0. ([#1639](https://github.com/googleapis/gax-java/issues/1639)) ([5c01174](https://github.com/googleapis/gax-java/commit/5c0117408ecfaec4e445b4fd813da6478415ea8e))
-
-### [2.12.2](https://github.com/googleapis/gax-java/compare/v2.12.1...v2.12.2) (2022-02-09)
-
-
-### Bug Fixes
-
-* REST: Make make LRO stub accept APIs of different versions ([#1622](https://github.com/googleapis/gax-java/issues/1622)) ([3ae8d85](https://github.com/googleapis/gax-java/commit/3ae8d850c5599ce487778d98d562d5b9b9e85d25))
-
-### [2.12.1](https://github.com/googleapis/gax-java/compare/v2.12.0...v2.12.1) (2022-02-09)
-
-
-### Bug Fixes
-
-* revert "feat: add api key support ([#1436](https://github.com/googleapis/gax-java/issues/1436))" ([#1617](https://github.com/googleapis/gax-java/issues/1617)) ([47f98b8](https://github.com/googleapis/gax-java/commit/47f98b872c6896ad2af37e30db440321c2adb492))
-
-## [2.12.0](https://github.com/googleapis/gax-java/compare/v2.11.0...v2.12.0) (2022-01-28)
-
-
-### Features
-
-* add REST interceptors infrastructure ([#1607](https://github.com/googleapis/gax-java/issues/1607)) ([0572eed](https://github.com/googleapis/gax-java/commit/0572eed8aa29879c74794b22e8ae79e414dd5821))
-
-## [2.11.0](https://github.com/googleapis/gax-java/compare/v2.10.0...v2.11.0) (2022-01-27)
-
-
-### Features
-
-* Add a builder to handle the common logic of extracting routing header values from request ([#1598](https://github.com/googleapis/gax-java/issues/1598)) ([2836baa](https://github.com/googleapis/gax-java/commit/2836baafa1114761cffbfdd4aee2322a4a931f8f))
-
-
-### Dependencies
-
-* update dependency com_google_protobuf to 3.19.3 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.api:api-common to 2.1.3 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.api.grpc:grpc-google-common-protos to 2.7.2 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.api.grpc:proto-google-common-protos to 2.7.2 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.errorprone:error_prone_annotations to v2.11.0 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.http-client:google-http-client to 1.41.2 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency com.google.http-client:google-http-client-gson to 1.41.2 ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-* update dependency io_grpc to 1.44.0 ([#1610](https://github.com/googleapis/gax-java/issues/1610)) ([734906e](https://github.com/googleapis/gax-java/commit/734906efd15064ea0d36b308f217508c9bf5ed42))
-
-## [2.10.0](https://github.com/googleapis/gax-java/compare/v2.9.0...v2.10.0) (2022-01-21)
-
-
-### Features
-
-* add api key support ([#1436](https://github.com/googleapis/gax-java/issues/1436)) ([5081ec6](https://github.com/googleapis/gax-java/commit/5081ec6541da8ca3f5a4c0d20aa75bd20010a642))
-* introduce HttpJsonClientCall, Listeners infrastructure and ServerStreaming support in REST transport ([#1599](https://github.com/googleapis/gax-java/issues/1599)) ([3c97529](https://github.com/googleapis/gax-java/commit/3c97529b8bd0e8141c5d722f887cb7ae1ed30b69))
-
-## [2.9.0](https://github.com/googleapis/gax-java/compare/v2.8.1...v2.9.0) (2022-01-14)
-
-
-### Features
-
-* pass a CallCredentials to grpc-java for DirectPath ([#1488](https://github.com/googleapis/gax-java/issues/1488)) ([4a7713a](https://github.com/googleapis/gax-java/commit/4a7713ad683e70380087437d6b52cbe3e115d1fb))
-
-### [2.8.1](https://www.github.com/googleapis/gax-java/compare/v2.8.0...v2.8.1) (2022-01-06)
-
-
-### Dependencies
-
-* update dependency com.google.api:api-common to 2.1.2 ([#1590](https://www.github.com/googleapis/gax-java/issues/1590)) ([1b34870](https://www.github.com/googleapis/gax-java/commit/1b34870358a26bd4542594b6c746dca190f65d24))
-* update dependency com.google.auto.value:auto-value to v1.9 ([1b34870](https://www.github.com/googleapis/gax-java/commit/1b34870358a26bd4542594b6c746dca190f65d24))
-
-## [2.8.0](https://www.github.com/googleapis/gax-java/compare/v2.7.1...v2.8.0) (2022-01-06)
-
-
-### Features
-
-* update DirectPath xds scheme ([#1585](https://www.github.com/googleapis/gax-java/issues/1585)) ([7915f85](https://www.github.com/googleapis/gax-java/commit/7915f850313ddfdf35332d976d2567f31c2aa8a7))
-
-
-### Dependencies
-
-* update dependency com.google.api.grpc:proto-google-common-protos to v2.7.1 ([#1587](https://www.github.com/googleapis/gax-java/issues/1587)) ([eb0e9d1](https://www.github.com/googleapis/gax-java/commit/eb0e9d106a64af5f583d75d7291cdc17652fd5e7))
-* update dependency com.google.http-client:google-http-client-bom to v1.41.0 ([eb0e9d1](https://www.github.com/googleapis/gax-java/commit/eb0e9d106a64af5f583d75d7291cdc17652fd5e7))
-* update dependency com.google.protobuf:protobuf-bom to v3.19.2 ([eb0e9d1](https://www.github.com/googleapis/gax-java/commit/eb0e9d106a64af5f583d75d7291cdc17652fd5e7))
-* upgrade common-protos to 2.7.0 ([#1579](https://www.github.com/googleapis/gax-java/issues/1579)) ([0a10f5f](https://www.github.com/googleapis/gax-java/commit/0a10f5fe77ab26b3ac7d4c590360945ead72eca1))
-
-### [2.7.1](https://www.github.com/googleapis/gax-java/compare/v2.7.0...v2.7.1) (2021-12-02)
-
-
-### Bug Fixes
-
-* fix gRPC code conversion ([#1555](https://www.github.com/googleapis/gax-java/issues/1555)) ([09b99d5](https://www.github.com/googleapis/gax-java/commit/09b99d591497b44c3c25b1a54abb0f1cb69d7376))
-* pass error message when creating ApiException ([#1556](https://www.github.com/googleapis/gax-java/issues/1556)) ([918ae41](https://www.github.com/googleapis/gax-java/commit/918ae419f84ad5721638ca10eca992333e9f7c3d))
-* revert generics syntax change in MockHttpService test utility ([#1574](https://www.github.com/googleapis/gax-java/issues/1574)) ([b629488](https://www.github.com/googleapis/gax-java/commit/b629488ffc7d68158158d9197695158f97229c7b))
-* update exception mapping on HTTP error responses ([#1570](https://www.github.com/googleapis/gax-java/issues/1570)) ([8a170d1](https://www.github.com/googleapis/gax-java/commit/8a170d19b42e9b13d4c69dcfbe531d4d4ca69c90))
-
-
-### Dependencies
-
-* update grpc to 1.42.1 ([#1559](https://www.github.com/googleapis/gax-java/issues/1559)) ([92b7632](https://www.github.com/googleapis/gax-java/commit/92b76325d54604c98c798c489b3a963fdf21a75c))
-* upgrade protobuf to 3.19.1 ([#1571](https://www.github.com/googleapis/gax-java/issues/1571)) ([7b354e7](https://www.github.com/googleapis/gax-java/commit/7b354e73b8ce49008bed51076afb255ca5dc68e4))
-
-## [2.7.0](https://www.github.com/googleapis/gax-java/compare/v2.6.0...v2.7.0) (2021-11-03)
-
-
-### Features
-
-* add batch throttled time to tracer ([#1463](https://www.github.com/googleapis/gax-java/issues/1463)) ([14c25cd](https://www.github.com/googleapis/gax-java/commit/14c25cdfae2c0602d99fcd07c9067138fc172a7f))
-* add google-c2p dependence to DirectPath ([#1521](https://www.github.com/googleapis/gax-java/issues/1521)) ([d4222e7](https://www.github.com/googleapis/gax-java/commit/d4222e757d35e874a57d030f2f964e8d61c71d6d))
-* next release from main branch is 2.7.0 ([#1530](https://www.github.com/googleapis/gax-java/issues/1530)) ([a96953e](https://www.github.com/googleapis/gax-java/commit/a96953e2c889ad9195b420ce5ae49b20258fb6ea))
-* pass request in ApiTracer ([#1491](https://www.github.com/googleapis/gax-java/issues/1491)) ([27bf265](https://www.github.com/googleapis/gax-java/commit/27bf2655120972d929e6118b73d8d556b0440fcf))
-
-
-### Bug Fixes
-
-* call ResponseMetadataHanlder#onTrailers before calling onClose ([#1549](https://www.github.com/googleapis/gax-java/issues/1549)) ([19a77a4](https://www.github.com/googleapis/gax-java/commit/19a77a4f6c62e84bba4879690992bbc494730d23))
-* declare depenencies of API surfaces as api ([#1535](https://www.github.com/googleapis/gax-java/issues/1535)) ([725414f](https://www.github.com/googleapis/gax-java/commit/725414f4ccb1e5ac4625790ea990c6c8dfa4fdff))
-
-## [2.6.0](https://www.github.com/googleapis/gax-java/compare/v2.5.3...v2.6.0) (2021-10-15)
-
-
-### Features
-
-* remove deprecated Generated annotation ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-
-
-### Bug Fixes
-
-* Fix com.google.rpc.Code to StatusCode.Code conversion logic ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-
-
-### Dependencies
-
-* update api-common to 2.0.5 ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-* update auto-value to 1.8.2 ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-* update com_google_protobuf to 3.18.1 ([#1519](https://www.github.com/googleapis/gax-java/issues/1519)) ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-* update google-http-client to 1.40.1 ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-* update grpc to 1.41.0 ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-* update guava to v31 ([2d76bff](https://www.github.com/googleapis/gax-java/commit/2d76bff6d64da818a3aff7ea0bdf5a36b82c3464))
-
-### [2.5.3](https://www.github.com/googleapis/gax-java/compare/v2.5.2...v2.5.3) (2021-10-13)
-
-
-### Bug Fixes
-
-* Fix `com.google.rpc.Code` to `StatusCode.Code` conversion  logic ([#1508](https://www.github.com/googleapis/gax-java/issues/1508)) ([61b1617](https://www.github.com/googleapis/gax-java/commit/61b161799faf292be1394111381f8a35e757b85a))
-
-### [2.5.2](https://www.github.com/googleapis/gax-java/compare/v2.5.1...v2.5.2) (2021-10-13)
-
-
-### Dependencies
-
-* release multiple artifacts at once ([#1506](https://www.github.com/googleapis/gax-java/issues/1506)) ([8c022f6](https://www.github.com/googleapis/gax-java/commit/8c022f69f7878280e00f200f65a931ff0f8cfe45))
-
-### [2.5.1](https://www.github.com/googleapis/gax-java/compare/v2.5.0...v2.5.1) (2021-10-08)
-
-
-### Dependencies
-
-* fix release pipeline ([#1500](https://www.github.com/googleapis/gax-java/issues/1500)) ([f8ae03b](https://www.github.com/googleapis/gax-java/commit/f8ae03bbf0389d5fd943d214c1058ee012be757b))
-
-## [2.5.0](https://www.github.com/googleapis/gax-java/compare/v2.4.1...v2.5.0) (2021-09-21)
-
-
-### Features
-
-* Add REST AIP-151 LRO support ([#1484](https://www.github.com/googleapis/gax-java/issues/1484)) ([95ca348](https://www.github.com/googleapis/gax-java/commit/95ca3482d272b5c5c5ac2c85ba007f0ba9f7b5cf))
-
-### [2.4.1](https://www.github.com/googleapis/gax-java/compare/v2.4.0...v2.4.1) (2021-09-08)
-
-
-### Bug Fixes
-
-* REGAPIC fix socket timeout for wait calls ([#1476](https://www.github.com/googleapis/gax-java/issues/1476)) ([86c68b3](https://www.github.com/googleapis/gax-java/commit/86c68b3ffd241f6932516d0e7b5d9ae5714b89e0))
-
-## [2.4.0](https://www.github.com/googleapis/gax-java/compare/v2.3.0...v2.4.0) (2021-08-27)
-
-
-### Bug Fixes
-
-* Fix PATCH being unsupported ([#1465](https://www.github.com/googleapis/gax-java/issues/1465)) ([2c6ac24](https://www.github.com/googleapis/gax-java/commit/2c6ac24b1fce1de356e69370bbe6a4348825e3f9))
-
-
-### Dependencies
-
-* update google-common-prots and google-http-client ([#1471](https://www.github.com/googleapis/gax-java/issues/1471)) ([80e17a3](https://www.github.com/googleapis/gax-java/commit/80e17a35feb00aff0af3a65876625c705eb6ca46))
-
-## [2.3.0](https://www.github.com/googleapis/gax-java/compare/v2.2.0...v2.3.0) (2021-08-16)
-
-
-### Features
-
-* add custom options to ApiCallContext ([#1435](https://www.github.com/googleapis/gax-java/issues/1435)) ([0fe20f3](https://www.github.com/googleapis/gax-java/commit/0fe20f379feba1570e562e60e3f0bf7cc4e485bd))
-* add UseJwtAccessWithScope to GoogleCredentialsProvider ([#1420](https://www.github.com/googleapis/gax-java/issues/1420)) ([ed39c34](https://www.github.com/googleapis/gax-java/commit/ed39c34693783460fc03effb47e7027914cfb5bc))
-
-## [2.2.0](https://www.github.com/googleapis/gax-java/compare/v2.1.0...v2.2.0) (2021-08-13)
-
-
-### Features
-
-* Add AIP-151 LRO OperationsClient to gax-httpjson ([#1458](https://www.github.com/googleapis/gax-java/issues/1458)) ([314acb6](https://www.github.com/googleapis/gax-java/commit/314acb6a5c335732e8406bec86f6c37296ebf3f3))
-
-## [2.1.0](https://www.github.com/googleapis/gax-java/compare/v2.0.0...v2.1.0) (2021-08-11)
-
-
-### Features
-
-* add allowNonDefaultServiceAccount option for DirectPath ([#1433](https://www.github.com/googleapis/gax-java/issues/1433)) ([209b494](https://www.github.com/googleapis/gax-java/commit/209b4944feba1c62be2c9de4545e3b01a806b738))
-
-
-### Bug Fixes
-
-* fix httpjson executor ([#1448](https://www.github.com/googleapis/gax-java/issues/1448)) ([8f48b70](https://www.github.com/googleapis/gax-java/commit/8f48b7027b95e8e75872d1f9dac537ea697d0acc))
-* make closeAsync don't interrupt running thread ([#1446](https://www.github.com/googleapis/gax-java/issues/1446)) ([7c6c298](https://www.github.com/googleapis/gax-java/commit/7c6c29824487346d444730388ea6967408692696))
-
-
-### Dependencies
-
-* update dependency com.google.api:api-common to v2.0.1 ([#1452](https://www.github.com/googleapis/gax-java/issues/1452)) ([a52f16f](https://www.github.com/googleapis/gax-java/commit/a52f16f6cef8340357acb374ff31c8a6f248403c))
-
-## [2.0.0](https://www.github.com/googleapis/gax-java/compare/v1.67.0...v2.0.0) (2021-07-30)
-
-
-### Features
-
-* promote to 2.0.0 ([#1444](https://www.github.com/googleapis/gax-java/issues/1444)) ([776b1aa](https://www.github.com/googleapis/gax-java/commit/776b1aa73022bedec55e69732245b73cd04608f8))
-
-
-### Bug Fixes
-
-* stop overriding default grpc executor ([#1355](https://www.github.com/googleapis/gax-java/issues/1355)) ([b1f8c43](https://www.github.com/googleapis/gax-java/commit/b1f8c43cc90eb8e5ef78d142878841689356738c))
-
-
-### Dependencies
-
-* update api-common, guava, google-auth-library-credentials ([#1442](https://www.github.com/googleapis/gax-java/issues/1442)) ([2925ed7](https://www.github.com/googleapis/gax-java/commit/2925ed78cfb74db07a87da28839aeebc9027ac72))
-
-## [1.67.0](https://www.github.com/googleapis/gax-java/compare/v1.66.0...v1.67.0) (2021-07-19)
-
-
-### Features
-
-* introduce closeAsync to Batcher ([#1423](https://www.github.com/googleapis/gax-java/issues/1423)) ([aab5288](https://www.github.com/googleapis/gax-java/commit/aab528803405c2b5f9fc89641f47abff948a876d))
-* optimize unary callables to not wait for trailers ([#1356](https://www.github.com/googleapis/gax-java/issues/1356)) ([dd5f955](https://www.github.com/googleapis/gax-java/commit/dd5f955a3ab740c677fbc6f1247094798eb814a3))
-* update DirectPath environment variables ([#1412](https://www.github.com/googleapis/gax-java/issues/1412)) ([4f63b61](https://www.github.com/googleapis/gax-java/commit/4f63b61f1259936aa4a1eaf9162218c787b92f2a))
-
-
-### Bug Fixes
-
-* remove `extends ApiMessage` from `HttpJsonStubCallableFactory` definition ([#1426](https://www.github.com/googleapis/gax-java/issues/1426)) ([87636a5](https://www.github.com/googleapis/gax-java/commit/87636a5812874a77e9004aab07607121efa43736))
-
-## [1.66.0](https://www.github.com/googleapis/gax-java/compare/v1.65.1...v1.66.0) (2021-06-24)
-
-
-### Features
-
-* make ApiTracer internal API ([#1414](https://www.github.com/googleapis/gax-java/issues/1414)) ([e3e8462](https://www.github.com/googleapis/gax-java/commit/e3e8462a2f9e866480ec2106dc59555d41ea4bb5))
-
-### [1.65.1](https://www.github.com/googleapis/gax-java/compare/v1.65.0...v1.65.1) (2021-06-08)
-
-
-### Bug Fixes
-
-* fix grammar in StubSetting comment ([#1397](https://www.github.com/googleapis/gax-java/issues/1397)) ([b015910](https://www.github.com/googleapis/gax-java/commit/b0159102b52fd4b778a9bde15b1acd2e9fa6958e))
-
-## [1.65.0](https://www.github.com/googleapis/gax-java/compare/v1.64.0...v1.65.0) (2021-06-02)
-
-
-### Features
-
-* add mtls feature to http and grpc transport provider ([#1249](https://www.github.com/googleapis/gax-java/issues/1249)) ([b863041](https://www.github.com/googleapis/gax-java/commit/b863041bc4c03c8766e0feca8cb10f531373dc44))
-
-## [1.64.0](https://www.github.com/googleapis/gax-java/compare/v1.63.4...v1.64.0) (2021-05-10)
-
-
-### Features
-
-* release 1.64.0 ([#1375](https://www.github.com/googleapis/gax-java/issues/1375)) ([499682e](https://www.github.com/googleapis/gax-java/commit/499682ec3b96ddeaac75f6e71cc3bc85a854da97))
-
-### [1.63.4](https://www.github.com/googleapis/gax-java/compare/v1.63.3...v1.63.4) (2021-05-07)
-
-
-### Bug Fixes
-
-* Make x-goog-api-client header report rest-based transport clients with `rest/` token instead of `httpson/`. ([#1370](https://www.github.com/googleapis/gax-java/issues/1370)) ([b1b0b49](https://www.github.com/googleapis/gax-java/commit/b1b0b498ba188a51b17d179988074bcf34fb7590))
-
-### [1.63.3](https://www.github.com/googleapis/gax-java/compare/v1.63.2...v1.63.3) (2021-05-04)
-
-
-### Bug Fixes
-
-* fix flaky tests and non blocking semaphore ([#1365](https://www.github.com/googleapis/gax-java/issues/1365)) ([fc8e520](https://www.github.com/googleapis/gax-java/commit/fc8e520acfaf843ac61e806bdb4b5fe393d0b447))
-* Remove a flacky test in FlowControllerTest ([#1360](https://www.github.com/googleapis/gax-java/issues/1360)) ([2cca0bf](https://www.github.com/googleapis/gax-java/commit/2cca0bf9e96271dd52e8bffa00b8f2d45d358d35))
-
-### [1.63.2](https://www.github.com/googleapis/gax-java/compare/v1.63.1...v1.63.2) (2021-04-30)
-
-
-### Bug Fixes
-
-* Remove default value handling ([#1353](https://www.github.com/googleapis/gax-java/issues/1353)) ([ed0fc79](https://www.github.com/googleapis/gax-java/commit/ed0fc791b22db45bd20de890b0abecd1839d2d86))
-
-
-### Dependencies
-
-* remove codecov.io ([#1354](https://www.github.com/googleapis/gax-java/issues/1354)) ([06a53ac](https://www.github.com/googleapis/gax-java/commit/06a53aca36ed0825122be160479b1ea0ba8635a0))
-
-### [1.63.1](https://www.github.com/googleapis/gax-java/compare/v1.63.0...v1.63.1) (2021-04-26)
-
-
-### Bug Fixes
-
-* fix dynamic flow control setting checks ([#1347](https://www.github.com/googleapis/gax-java/issues/1347)) ([69458b4](https://www.github.com/googleapis/gax-java/commit/69458b4deefe5b9c2c33a3b51389face968ff52f))
-* fix watchdog NPE red herring ([#1344](https://www.github.com/googleapis/gax-java/issues/1344)) ([06dbf12](https://www.github.com/googleapis/gax-java/commit/06dbf129ce63d28430e1022137679c9cfdf433ee))
-
-## [1.63.0](https://www.github.com/googleapis/gax-java/compare/v1.62.0...v1.63.0) (2021-04-05)
-
-
-### Features
-
-* add setLogicalTimeout helper to RetrySettings ([#1334](https://www.github.com/googleapis/gax-java/issues/1334)) ([97d3214](https://www.github.com/googleapis/gax-java/commit/97d32144e9de38a9e351dc34270aa41aef351151))
-* dynamic flow control for batcher part 2 ([#1310](https://www.github.com/googleapis/gax-java/issues/1310)) ([20f6ecf](https://www.github.com/googleapis/gax-java/commit/20f6ecf4807bb4dffd0fa80717302c1f46b1d789))
-* dynamic flow control p3: add FlowControllerEventStats ([#1332](https://www.github.com/googleapis/gax-java/issues/1332)) ([5329ea4](https://www.github.com/googleapis/gax-java/commit/5329ea43c024ca14cea1012c5ab46e694e199492))
-* support retry settings and retryable codes in call context ([#1238](https://www.github.com/googleapis/gax-java/issues/1238)) ([7f7aa25](https://www.github.com/googleapis/gax-java/commit/7f7aa252ce96413cb09e01cc2e76672b167b1baf))
-* wrap non-retryable RPCs in retry machinery ([#1328](https://www.github.com/googleapis/gax-java/issues/1328)) ([51c40ab](https://www.github.com/googleapis/gax-java/commit/51c40abd408ab0637f3b65cf5697a4ee85a544a4))
-
-
-### Bug Fixes
-
-* add BetaApi tag to setLogicalTimeout ([#1335](https://www.github.com/googleapis/gax-java/issues/1335)) ([fc7169d](https://www.github.com/googleapis/gax-java/commit/fc7169d431baf2db90992241a0ef3d40c72567a5))
-* retain user RPC timeout if set via withTimeout ([#1324](https://www.github.com/googleapis/gax-java/issues/1324)) ([3fe1db9](https://www.github.com/googleapis/gax-java/commit/3fe1db913b134e4fddee4c769ee4497847d8e01f))
-
-
-### Documentation
-
-* cloud rad java doc generation ([#1336](https://www.github.com/googleapis/gax-java/issues/1336)) ([751ccf3](https://www.github.com/googleapis/gax-java/commit/751ccf3cb351cd5a037104242cdb763a104d6bc3))
-
-## [1.62.0](https://www.github.com/googleapis/gax-java/compare/v1.61.0...v1.62.0) (2021-02-25)
-
-
-### ⚠ BREAKING CHANGES
-
-* deprecate RetrySettings.isJittered [gax-java] (#1308)
-
-### Features
-
-* deprecate RetrySettings.isJittered [gax-java] ([#1308](https://www.github.com/googleapis/gax-java/issues/1308)) ([68644a4](https://www.github.com/googleapis/gax-java/commit/68644a4e24f29223f8f533a3d353dff7457d9737))
-* dynamic flow control part 1 - add FlowController to Batcher ([#1289](https://www.github.com/googleapis/gax-java/issues/1289)) ([bae5eb6](https://www.github.com/googleapis/gax-java/commit/bae5eb6070e690c26b95e7b908d15300aa54ef1c))
-
-
-### Bug Fixes
-
-* prevent unchecked warnings in gax-httpjson ([#1306](https://www.github.com/googleapis/gax-java/issues/1306)) ([ee370f6](https://www.github.com/googleapis/gax-java/commit/ee370f62c5d411738a9b25cf4cfc095aa06d9e07))
-* remove unused @InternalExtensionOnly from CallContext classes ([#1304](https://www.github.com/googleapis/gax-java/issues/1304)) ([a8d3a2d](https://www.github.com/googleapis/gax-java/commit/a8d3a2dca96efdb1ce154a976c3e0844e3f501d6))
-
-
-### Dependencies
-
-* update google-auth-library to 0.24.0 ([#1315](https://www.github.com/googleapis/gax-java/issues/1315)) ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-* update google-common-protos to 2.0.1 ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-* update google-http-client to 1.39.0 ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-* update google-iam ([#1313](https://www.github.com/googleapis/gax-java/issues/1313)) ([327b53c](https://www.github.com/googleapis/gax-java/commit/327b53ca7739d9be6e24305b23af2c7a35cb6f4d))
-* update gRPC to 1.36.0 ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-* update opencensus to 0.28.0 ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-* update protobuf to 3.15.2 ([772331e](https://www.github.com/googleapis/gax-java/commit/772331eda5c47e9de376e505e7d8ee502b01ec72))
-
-## [1.61.0](https://www.github.com/googleapis/gax-java/compare/v1.60.1...v1.61.0) (2021-02-17)
-
-
-### Features
-
-* **operations:** Add WaitOperation API surface [gax-java] ([#1284](https://www.github.com/googleapis/gax-java/issues/1284)) ([68761a7](https://www.github.com/googleapis/gax-java/commit/68761a7de17489c02362e079ca766ee06da5e247))
-
-
-### Bug Fixes
-
-* InstantiatingGrpcChannelProvider.toBuilder() should carry over all config data ([#1298](https://www.github.com/googleapis/gax-java/issues/1298)) ([0bc5dc5](https://www.github.com/googleapis/gax-java/commit/0bc5dc54c8eea00f2dc0e1d6a4a42e3417c64fc7))
-* **lro:** Add Operation name to headers in {Get,List}Operation requests [gax-java] ([#1281](https://www.github.com/googleapis/gax-java/issues/1281)) ([721617b](https://www.github.com/googleapis/gax-java/commit/721617b0cb80ebcd40c3aa2f6c5b86f679dad811))
-* **operations:** Make Operations a manual client [gax-java] ([#1282](https://www.github.com/googleapis/gax-java/issues/1282)) ([5be66cd](https://www.github.com/googleapis/gax-java/commit/5be66cd3ebf2ccf34f21db40463a2d9115a77798))
-
-
-### Dependencies
-
-* update com.google.http-client:google-http-client to 1.38.1 ([#1265](https://www.github.com/googleapis/gax-java/issues/1265)) ([5815a7c](https://www.github.com/googleapis/gax-java/commit/5815a7ce815cc2fc47b39b928010de0c2cea8716))
-* update common protos ([#1258](https://www.github.com/googleapis/gax-java/issues/1258)) ([7287e84](https://www.github.com/googleapis/gax-java/commit/7287e84979ba9076e4888ec3678995c08f1ea690))
-* update gRPC ([#1263](https://www.github.com/googleapis/gax-java/issues/1263)) ([95a7dab](https://www.github.com/googleapis/gax-java/commit/95a7dab77800dffaf551018c85e1d78596411e8f))
-* update Guava ([#1262](https://www.github.com/googleapis/gax-java/issues/1262)) ([cdc0366](https://www.github.com/googleapis/gax-java/commit/cdc0366d23317d6fddd3dc86592664449aaa8a6f))
-* update iam protos to v1.0.7 ([#1266](https://www.github.com/googleapis/gax-java/issues/1266)) ([69b6dc4](https://www.github.com/googleapis/gax-java/commit/69b6dc44f5e81d5919553b9de6248346d172adcd))
-* update protobuf ([#1256](https://www.github.com/googleapis/gax-java/issues/1256)) ([ef9b3aa](https://www.github.com/googleapis/gax-java/commit/ef9b3aaac30406b0b17a985ab959530c1254b145))
-
-### [1.60.1](https://www.github.com/googleapis/gax-java/compare/v1.60.0...v1.60.1) (2020-11-19)
-
-
-### Bug Fixes
-
-* check Compute Engine environment for DirectPath ([#1250](https://www.github.com/googleapis/gax-java/issues/1250)) ([656b613](https://www.github.com/googleapis/gax-java/commit/656b613d2fe73e5bd19d43d4a2d8d0c6bb9ad5f2))
-
-
-### Dependencies
-
-* update api-common to 1.10.1 ([#1240](https://www.github.com/googleapis/gax-java/issues/1240)) ([d8b2bf7](https://www.github.com/googleapis/gax-java/commit/d8b2bf7b59d83a11e2e0eba703ed758fd1adb0ce))
-* update auth libaries ([#1251](https://www.github.com/googleapis/gax-java/issues/1251)) ([d455da2](https://www.github.com/googleapis/gax-java/commit/d455da2cd73f1e015d7570e8d634864a38bdb042))
-* update autovalue annotations ([#1246](https://www.github.com/googleapis/gax-java/issues/1246)) ([60bb103](https://www.github.com/googleapis/gax-java/commit/60bb10326cd3a0092d69e8388eb5f7fed55a715c))
-* update dependency com.google.auto.value:auto-value to v1.7.4 ([#1031](https://www.github.com/googleapis/gax-java/issues/1031)) ([1e7e13c](https://www.github.com/googleapis/gax-java/commit/1e7e13c07bf4c79d0b3cbfd0f15a4908278c1ffa))
-* update google-http-client to 1.38.0 ([#1244](https://www.github.com/googleapis/gax-java/issues/1244)) ([6b53f0f](https://www.github.com/googleapis/gax-java/commit/6b53f0fe3a95346596c670f62d34267483a12c68))
-* update Guava to 30.0-android ([#1237](https://www.github.com/googleapis/gax-java/issues/1237)) ([64806c4](https://www.github.com/googleapis/gax-java/commit/64806c474f1aab87ed62f59e9746aa22c5982e96))
-* update threetenbp to 1.5.0 ([#1243](https://www.github.com/googleapis/gax-java/issues/1243)) ([6232599](https://www.github.com/googleapis/gax-java/commit/6232599506fda164e5675162e71809a78258efbd))
-
-## [1.60.0](https://www.github.com/googleapis/gax-java/compare/v1.59.1...v1.60.0) (2020-10-19)
-
-
-### Features
-
-* REST Gapic (REGAPIC) Support  ([#1177](https://www.github.com/googleapis/gax-java/issues/1177)) ([12b18ee](https://www.github.com/googleapis/gax-java/commit/12b18ee255d3fabe13bb3969df40753b29f830d5))
-
-
-### Bug Fixes
-
-* prevent npe caused by missing parentheses ([#1198](https://www.github.com/googleapis/gax-java/issues/1198)) ([b856351](https://www.github.com/googleapis/gax-java/commit/b85635123f987f9808086f14a58dd8c7418a3bd8))
-
-
-### Dependencies
-
-* upgrade grpc to 1.32.2 ([#1212](https://www.github.com/googleapis/gax-java/issues/1212)) ([03c4c0f](https://www.github.com/googleapis/gax-java/commit/03c4c0f621f439c30752122568d2a9a7703e5e16))
-
-### [1.59.1](https://www.github.com/googleapis/gax-java/compare/v1.59.0...v1.59.1) (2020-10-05)
-
-
-### Bug Fixes
-
-* Fix race condition in BatcherImpl flush ([#1200](https://www.github.com/googleapis/gax-java/issues/1200)) ([c6308c9](https://www.github.com/googleapis/gax-java/commit/c6308c906171ce05765ccacb716aa7162d95d9a2))
-* update owners file with actools-java ([#1194](https://www.github.com/googleapis/gax-java/issues/1194)) ([9977dd2](https://www.github.com/googleapis/gax-java/commit/9977dd2564ff6919fc6a6b658eb69b5ea8a66520))
-
-## [1.59.0](https://www.github.com/googleapis/gax-java/compare/v1.58.3...v1.59.0) (2020-09-28)
-
-
-### Features
-
-* Allow user-agents to be specified by both internal headers and user headers ([#1190](https://www.github.com/googleapis/gax-java/issues/1190)) ([266329e](https://www.github.com/googleapis/gax-java/commit/266329e89642bfc6be579e600d3f995f4416ae4e)), closes [/github.com/googleapis/java-bigtable/pull/404#pullrequestreview-480972135](https://www.github.com/googleapis//github.com/googleapis/java-bigtable/pull/404/issues/pullrequestreview-480972135)
-
-
-### Bug Fixes
-
-* truncate RPC timeouts to time remaining in totalTimeout ([#1191](https://www.github.com/googleapis/gax-java/issues/1191)) ([1d0c940](https://www.github.com/googleapis/gax-java/commit/1d0c94061bab124be81a649ac3fa1ce5d9a2df23))
-
-
-### Dependencies
-
-* update guava to 29.0-android ([#1174](https://www.github.com/googleapis/gax-java/issues/1174)) ([287cada](https://www.github.com/googleapis/gax-java/commit/287cadae528549545da9e7e9d63fd70c1268e3c1)), closes [#1151](https://www.github.com/googleapis/gax-java/issues/1151)
-
-### [1.58.3](https://www.github.com/googleapis/gax-java/compare/v1.58.2...v1.58.3) (2020-09-15)
-
-
-### Bug Fixes
-
-* [gax-java] Add speedy Bazel builds to Travis ([#1181](https://www.github.com/googleapis/gax-java/issues/1181)) ([2fb85fe](https://www.github.com/googleapis/gax-java/commit/2fb85fed095c6043ee39b63a0f7dff3fd93cbd7b))
-* [gax-java] add Vim files to .gitignore ([#1179](https://www.github.com/googleapis/gax-java/issues/1179)) ([2de22b6](https://www.github.com/googleapis/gax-java/commit/2de22b6645fbfd7ada7d0067e5cdd3c2039ec190))
-* [gax-java] Fix broken Bazel build ([#1180](https://www.github.com/googleapis/gax-java/issues/1180)) ([834c05e](https://www.github.com/googleapis/gax-java/commit/834c05e1d35a17f90bf8cd1b2cdce40bea451c95))
-
-### [1.58.2](https://www.github.com/googleapis/gax-java/compare/v1.58.1...v1.58.2) (2020-08-07)
-
-
-### Bug Fixes
-
-* Settings objects should not try to read quotaProjectId from credentials ([#1162](https://www.github.com/googleapis/gax-java/issues/1162)) ([1b09bcf](https://www.github.com/googleapis/gax-java/commit/1b09bcff1ddfaed8cfa58b92c787f8fc9b08abef))
-
-### [1.58.1](https://www.github.com/googleapis/gax-java/compare/v1.58.0...v1.58.1) (2020-08-06)
-
-
-### Bug Fixes
-
-* fix dependencies.properties resource file creation during deployment ([#1163](https://www.github.com/googleapis/gax-java/issues/1163)) ([3e7e1f1](https://www.github.com/googleapis/gax-java/commit/3e7e1f1e64bdeb23a51b5155faea975beec0bc84))
-* Watchdog.shutdownNow() does not shutdown executor ([#1158](https://www.github.com/googleapis/gax-java/issues/1158)) ([6241a21](https://www.github.com/googleapis/gax-java/commit/6241a2118690d07dd28ffb9447423363f3f914e4))
-
-## [1.58.0](https://www.github.com/googleapis/gax-java/compare/v1.57.2...v1.58.0) (2020-07-31)
-
-
-### Features
-
-* add retry logging ([#1160](https://www.github.com/googleapis/gax-java/issues/1160)) ([1575715](https://www.github.com/googleapis/gax-java/commit/15757151d4965276bd01e6772c10288959bb17ec))
-* enable setting quota_project_id ([#1128](https://www.github.com/googleapis/gax-java/issues/1128)) ([20bb200](https://www.github.com/googleapis/gax-java/commit/20bb200c8019ad1df8acbfe210cea7d5e9a9a57c))
-* non-retryable RPCs use totalTimeout ([#1149](https://www.github.com/googleapis/gax-java/issues/1149)) ([b7646a3](https://www.github.com/googleapis/gax-java/commit/b7646a3a959b7e5ef40158851f26ce6701da8ca4))
-
-
-### Bug Fixes
-
-* retain context timeouts in ServerStreamingAttemptCallable ([#1155](https://www.github.com/googleapis/gax-java/issues/1155)) ([461ff84](https://www.github.com/googleapis/gax-java/commit/461ff846ca551c2242bf6c60e61234997d0ba58e))
-
-### [1.57.2](https://www.github.com/googleapis/gax-java/compare/v1.57.1...v1.57.2) (2020-07-21)
-
-
-### Bug Fixes
-
-* Fix javadoc generation on Java11 ([#1145](https://www.github.com/googleapis/gax-java/issues/1145)) ([c7a039e](https://www.github.com/googleapis/gax-java/commit/c7a039e07be02298d9dd906b08e1e1bb995e85e2))
-* Preconditions only supports %s format ([#1153](https://www.github.com/googleapis/gax-java/issues/1153)) ([8145311](https://www.github.com/googleapis/gax-java/commit/8145311b38fdd3bf82a4958f8aef5313857b70c0))
-
-### [1.57.1](https://www.github.com/googleapis/gax-java/compare/v1.57.0...v1.57.1) (2020-07-07)
-
-
-### Bug Fixes
-
-* add back javax.annotation dependency ([#1129](https://www.github.com/googleapis/gax-java/issues/1129)) ([77a4cc3](https://www.github.com/googleapis/gax-java/commit/77a4cc373914396dd343891e38cf743166668c96))
-
-
-### Dependencies
-
-* update google-auth-library to 0.21.0 ([#1134](https://www.github.com/googleapis/gax-java/issues/1134)) ([6528e5c](https://www.github.com/googleapis/gax-java/commit/6528e5cb9cec50ef01c0d2601c6db518df825747))
diff --git a/RELEASING.md b/RELEASING.md
deleted file mode 100644
index 37e4b2044..000000000
--- a/RELEASING.md
+++ /dev/null
@@ -1,72 +0,0 @@
-One-time setup
-==============
-
-Set up Sonatype Account
------------------------
-* Sign up for a Sonatype JIRA account [here](https://issues.sonatype.org)
-* Click *Sign Up* in the login box, follow instructions
-
-Get access to repository
-------------------------
-* Go to [community support](https://issues.sonatype.org/browse/OSSRH)
-* Ask for publish rights by creating an issue similar to [this one](https://issues.sonatype.org/browse/OSSRH-32031)
-  * You must be logged in to create a new issue
-  * Use the *Create* button at the top tab
-
-* Generate the key `gpg --gen-key`
-  * Keep the defaults, but specify a passphrase
-
-* Determine your `gpg` version: `gpg --version`
-
-* Find the ID of your public key
-  * If you're using GPG version 1.y.z, `gpg --list-secret-keys`
-    * Look for the line with format `sec   2048R/ABCDEFGH 2015-11-17`
-    * The `ABCDEFGH` is the ID for your public key
-  * If you're using GPG version 2.y.z `gpg --list-secret-keys --keyid-format LONG`
-    * Look for line with format `sec   rsa2048/ABCDEFGHIJKLMNOP`
-    * The `ABCDEFGHIJKLMNOP` is the ID. It is 16-byte long, but Gradle
-      only support 8-byte keys. Use the *last* 8 bytes of the key when
-      following the rest of this document.
-    * `gpg --export-secret-keys > $HOME/.gnupg/secring.gpg`
-
-* Upload your public key to a public server: `gpg --send-keys --keyserver hkp://pgp.mit.edu <YOUR-KEY-ID-HERE>`
-
-Add deploy credential settings
-------------------------
-* Create a settings file at `$HOME/.gradle/gradle.properties` with your key information and your sonatype username/password
-
-```
-signing.keyId=<YOUR-KEY-ID-HERE>
-signing.password=<YOUR-PASSWORD-HERE>
-signing.secretKeyRingFile=/usr/local/google/home/<YOUR-USER-NAME>/.gnupg/secring.gpg
-
-ossrhUsername=<YOUR-NEXUS-USERNAME>
-ossrhPassword=<YOUR-NEXUS-PASSWORD>
-```
-
-Install releasetool
--------------------
-See [releasetool](https://github.com/googleapis/releasetool) for installation instructions. You will
-need python 3.6+ to run this tool.
-
-To prepare a release
-====================
-
-Update version and deploy to Sonatype
--------------------------------------
-1. Run `releasetool start`. Select "minor" or "patch" for the release type. This will bump the
-   artifact versions, ask you to edit release notes, and create the release pull request. When
-   prompted, choose to autorelease.
-  * Note: be sure to make these notes nice as they will be used for the release notes as well.
-2. Request a review on the PR.
-3. Submit the PR.
-4. Automation will run in the background to handle the release.
-5. It will take some time (~10 min to ~8 hours) for the package to transition
-6. Automation will publish a new release on Github using releasetool and publish javadocs to
-   https://googleapis.dev/java/gax/latest.
-
-Bump development version
-------------------------
-1. Run `releasetool start` again, but specify "snapshot" when prompted for the type of release.
-   This will bump the artifact versions and create a new snapshot pull request.
-2. Review and submit the PR.
diff --git a/WORKSPACE b/WORKSPACE
deleted file mode 100644
index 9c65d85e8..000000000
--- a/WORKSPACE
+++ /dev/null
@@ -1,45 +0,0 @@
-workspace(name = "com_google_api_gax_java")
-
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-load("//:repository_rules.bzl", "com_google_api_gax_java_properties")
-
-com_google_api_gax_java_properties(
-    name = "com_google_api_gax_java_properties",
-    file = "//:dependencies.properties",
-)
-
-load("//:repositories.bzl", "com_google_api_gax_java_repositories")
-
-com_google_api_gax_java_repositories()
-
-load("@com_google_protobuf//:protobuf_deps.bzl",
-    "PROTOBUF_MAVEN_ARTIFACTS", "protobuf_deps")
-
-# From protobuf 3.19, protobuf project started to provide
-# PROTOBUF_MAVEN_ARTIFACTS variable so that the Bazel users can resolve their
-# dependencies through maven_install.
-# https://github.com/protocolbuffers/protobuf/issues/9132
-RULES_JVM_EXTERNAL_TAG = "4.2"
-RULES_JVM_EXTERNAL_SHA = "cd1a77b7b02e8e008439ca76fd34f5b07aecb8c752961f9640dea15e9e5ba1ca"
-http_archive(
-    name = "rules_jvm_external",
-    strip_prefix = "rules_jvm_external-%s" % RULES_JVM_EXTERNAL_TAG,
-    sha256 = RULES_JVM_EXTERNAL_SHA,
-    url = "https://github.com/bazelbuild/rules_jvm_external/archive/%s.zip" % RULES_JVM_EXTERNAL_TAG,
-)
-
-load("@rules_jvm_external//:defs.bzl", "maven_install")
-
-maven_install(
-    artifacts = PROTOBUF_MAVEN_ARTIFACTS,
-    generate_compat_repositories = True,
-    repositories = [
-        "https://repo.maven.apache.org/maven2/",
-    ],
-)
-
-protobuf_deps()
-
-load("@io_grpc_grpc_java//:repositories.bzl", "grpc_java_repositories")
-
-grpc_java_repositories()
diff --git a/build.gradle b/build.gradle
deleted file mode 100644
index d6a194c00..000000000
--- a/build.gradle
+++ /dev/null
@@ -1,329 +0,0 @@
-import groovy.io.FileType
-
-plugins {
-  id 'java'
-  id 'io.github.gradle-nexus.publish-plugin' version '1.1.0'
-
-  id 'com.diffplug.eclipse.apt' version '3.40.0' apply false
-  id 'com.dorongold.task-tree' version '2.1.1' apply false
-  id 'com.github.johnrengelman.shadow' version '7.1.2' apply false
-  id 'com.github.sherter.google-java-format' version '0.9' apply false
-
-  id 'org.sonarqube' version '3.5.0.2730'
-}
-
-// TODO: Populate this from dependencies.properties version property (for proper Gradle-Bazel sync)
-project.version = "2.20.1" // {x-version-update:gax:current}
-
-allprojects {
-  group = 'com.google.api'
-}
-
-// Project names not using the default publication configuration
-def nonJavaProjects = ['gax-bom']
-
-ext {
-  libraryVendor = 'Google'
-
-  // Load Dependencies shared between Bazel and Gradle build scripts
-  libraries = new Properties()
-  file('dependencies.properties').withReader { libraries.load(it) }
-  // Gradle-specific build script dependencies
-  libraries.putAll(
-    'maven.io_grpc_grpc_bom': "io.grpc:grpc-bom:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_core': "io.grpc:grpc-core:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_context': "io.grpc:grpc-context:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_stub': "io.grpc:grpc-stub:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_api': "io.grpc:grpc-api:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_auth': "io.grpc:grpc-auth:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_protobuf': "io.grpc:grpc-protobuf:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_netty_shaded': "io.grpc:grpc-netty-shaded:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_alts': "io.grpc:grpc-alts:${libraries['version.io_grpc']}",
-    'maven.io_grpc_grpc_googleapis': "io.grpc:grpc-googleapis:${libraries['version.io_grpc']}",
-    'maven.com_google_protobuf': "com.google.protobuf:protobuf-java:${libraries['version.com_google_protobuf']}",
-    'maven.com_google_protobuf_java_util': "com.google.protobuf:protobuf-java-util:${libraries['version.com_google_protobuf']}")
-}
-
-nexusPublishing {
-  packageGroup = 'com.google.api'
-  repositories {
-    sonatype {
-      nexusUrl = uri('https://google.oss.sonatype.org/service/local/')
-      snapshotRepositoryUrl = uri('https://google.oss.sonatype.org/content/repositories/snapshots/')
-      username = findProperty('ossrhUsername')
-      password = findProperty('ossrhPassword')
-    }
-  }
-}
-
-def javaProjects = subprojects.findAll { !nonJavaProjects.contains(it.name) }
-configure(javaProjects) {
-  apply plugin: 'java-library'
-  apply plugin: 'eclipse'
-  apply plugin: 'idea'
-  apply plugin: 'jacoco'
-
-  apply plugin: 'com.diffplug.eclipse.apt'
-  apply plugin: 'com.dorongold.task-tree'
-  apply plugin: 'com.github.johnrengelman.shadow'
-  apply plugin: 'com.github.sherter.google-java-format'
-
-  sourceCompatibility = 1.8
-  targetCompatibility = 1.8
-
-  // Formatting tasks
-  // ================
-  googleJavaFormat {
-    toolVersion '1.7'
-    exclude '.apt_generated*/**'
-    exclude 'bin/**'
-    exclude 'build/**'
-    exclude 'bazel*/**'
-  }
-  test.dependsOn verifyGoogleJavaFormat
-
-  task verifyLicense {
-    doLast {
-      def licenseText = new File('license-header-javadoc.txt').text
-      def srcFiles = []
-      sourceSets
-          .collectMany{it.allJava.getSrcDirs()}
-          .grep{it.exists()}
-          .each{it.eachFileRecurse(FileType.FILES, {srcFiles << new Tuple(it, it.text)})}
-      srcFiles = srcFiles
-          .findAll{it.get(0).path.endsWith('.java')}
-          .collect{new Tuple(it.get(0), it.get(1).replaceAll('Copyright 20[0-9]{2}', 'Copyright 20xx'))}
-          .findAll{!it.get(1).startsWith(licenseText)}
-      if (srcFiles.asList().size() > 0) {
-        srcFiles.each({println 'missing license: ' + it.get(0)})
-        throw new IllegalStateException('Above files do not have licenses')
-      }
-    }
-  }
-  test.dependsOn verifyLicense
-
-  tasks.withType(JavaCompile) {
-    options.compilerArgs << '-Xlint:unchecked' << '-Xlint:deprecation'
-    // This flag is only available in JDK 9+. This flag ensures the generated
-    // bytecode is compatible with Java 8. (targetCompatibility = 1.8 is not
-    // sufficient)
-    options.compilerArgs.addAll(['--release', '8'])
-  }
-
-  // Dependencies
-  // ------------
-
-  repositories {
-    mavenLocal()
-    mavenCentral()
-  }
-
-  configurations {
-    shadowNoGuava
-    implementation.exclude group: 'com.google.guava', module: 'guava-jdk5'
-  }
-
-  jacoco.toolVersion = '0.8.5'
-  jacocoTestReport {
-    reports {
-      xml.required = true
-      html.required = true
-    }
-    afterEvaluate {
-      getClassDirectories().setFrom files(classDirectories.files.collect {
-        fileTree(dir: it, exclude: ['**/AutoValue_*'])
-      })
-    }
-  }
-  check.dependsOn jacocoTestReport
-
-
-  // Source jar
-  // ----------
-
-  task sourcesJar(type: Jar, dependsOn: classes) {
-    archiveClassifier = 'sources'
-
-    from sourceSets.main.allSource, sourceSets.test.allSource
-    exclude('**/*Test.java')
-  }
-
-  javadoc.options {
-    encoding = 'UTF-8'
-    links 'https://docs.oracle.com/javase/8/docs/api/'
-
-    if (JavaVersion.current().isJava8Compatible()) {
-      addStringOption('Xdoclint:all,-missing', '-quiet')
-    }
-    if (JavaVersion.current().isJava11Compatible()) {
-      addStringOption('-release', '8')
-    }
-  }
-
-  // JavaDocV1 html
-  // -------
-  task javadocJar(type: Jar) {
-    archiveClassifier = 'javadoc'
-    from javadoc
-  }
-
-  // JavaDocV3 - docFX
-  // -------
-  task javadocJarV3(type: Jar) {
-    archiveClassifier = 'javadoc'
-    from javadoc
-  }
-
-  // Test jar
-  // --------
-
-  task testlibJar(type: Jar, dependsOn: test) {
-    archiveClassifier = 'testlib'
-    from sourceSets.test.output
-
-    include('com/google/api/gax/rpc/testing/**')
-    include('com/google/api/gax/grpc/testing/**')
-    include('com/google/api/gax/httpjson/testing/**')
-  }
-
-  // ShadowJar
-  // ---------
-
-  shadowJar {
-    archiveClassifier = 'guavashaded'
-    relocate 'com.google.common', 'com.google.api.gax.repackaged.com.google.common'
-    relocate 'io.grpc.stub', 'com.google.api.gax.repackaged.io.grpc.stub'
-    relocate 'io.grpc.protobuf', 'com.google.api.gax.repackaged.io.grpc.protobuf'
-    configurations = [project.configurations.shadowNoGuava]
-    exclude('io/grpc/*')
-    exclude('io/grpc/internal/**')
-    exclude('io/grpc/inprocess/**')
-    exclude('io/grpc/util/**')
-  }
-
-  // Test Logging
-  // ------------
-
-  test {
-    testLogging {
-      events 'passed', 'skipped', 'failed', 'standardOut', 'standardError'
-      exceptionFormat = 'full'
-    }
-  }
-
-  // Eclipse annotation processing auto-setup
-  eclipse.synchronizationTasks eclipseJdtApt, eclipseJdt, eclipseFactorypath
-}
-
-def normalReleasableProjects = subprojects.findAll {
-  !nonJavaProjects.contains(it.name)
-}
-configure(normalReleasableProjects) {
-  apply plugin: 'maven-publish'
-  apply plugin: 'signing'
-
-  afterEvaluate {
-    publishing {
-      publications {
-        mavenJava(MavenPublication) {
-          version = project.version
-
-          from components.java
-
-          artifact javadocJar
-          artifact sourcesJar
-          artifact testlibJar
-
-          pom {
-            name = 'GAX (Google Api eXtensions) for Java'
-            packaging = 'jar'
-            artifactId = project.name
-            description = 'Google Api eXtensions for Java'
-            url = 'https://github.com/googleapis/gax-java'
-
-            scm {
-              url = 'https://github.com/googleapis/gax-java'
-              connection = 'scm:git:https://github.com/googleapis/gax-java.git'
-            }
-
-            licenses {
-              license {
-                name = 'BSD'
-                url = 'https://github.com/googleapis/gax-java/blob/master/LICENSE'
-              }
-            }
-
-            developers {
-              developer {
-                id = 'GoogleAPIs'
-                name = 'GoogleAPIs'
-                email = 'googleapis@googlegroups.com'
-                url = 'https://github.com/googleapis/gax-java'
-                organization = 'Google LLC'
-                organizationUrl = 'https://www.google.com'
-              }
-            }
-          }
-        }
-      }
-      repositories {
-        maven {
-          url 'https://google.oss.sonatype.org/service/local/staging/deploy/maven2/'
-          credentials {
-            username = findProperty('ossrhUsername')
-            password = findProperty('ossrhPassword')
-          }
-        }
-      }
-    }
-  }
-
-  signing {
-    required { gradle.taskGraph.hasTask ":${name}:publishToSonatype" }
-    if (project.hasProperty('signing.gnupg.executable')) {
-      useGpgCmd()
-    }
-    sign publishing.publications
-  }
-}
-
-javadoc.options {
-  encoding = 'UTF-8'
-  links 'https://docs.oracle.com/javase/7/docs/api/'
-}
-
-// JavaDocV1 html
-// -------
-task javadocCombined(type: Javadoc) {
-  source subprojects.collect {project -> project.sourceSets.main.allJava }
-  classpath = files(subprojects.collect {project -> project.sourceSets.main.compileClasspath})
-  destinationDir = file('tmp_docs')
-}
-
-// JavaDocV3 docFX
-// -------
-task javadocCombinedV3(type: Javadoc) {
-  source subprojects.collect {project -> project.sourceSets.main.allJava }
-  classpath = files(subprojects.collect {project -> project.sourceSets.main.compileClasspath})
-  destinationDir = file('tmp_docs/docfx-yml')
-
-  options.addStringOption('encoding', 'UTF-8')
-  options.addStringOption('doclet', 'com.microsoft.doclet.DocFxDoclet')
-  options.addStringOption('projectname', 'gax')
-  options.docletpath = [file(System.getenv('KOKORO_GFILE_DIR') + '/java-docfx-doclet-1.5.0.jar')]
-  // Newer Gradle 6 passes -notimestamp by default, which the doclet above doesn't understand:
-  // https://github.com/gradle/gradle/issues/11898
-  options.noTimestamp false
-}
-
-clean {
-  delete 'tmp_docs/'
-}
-
-sonarqube {
-  properties {
-    property 'sonar.projectKey', 'googleapis_gax-java'
-    property 'sonar.organization', 'googleapis'
-    property 'sonar.host.url', 'https://sonarcloud.io'
-  }
-}
diff --git a/dependabot.yml b/dependabot.yml
deleted file mode 100644
index bd36675ae..000000000
--- a/dependabot.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "maven"
-    directory: "/"
-    schedule:
-      interval: "daily"
-    # Disable version updates for Maven dependencies
-    open-pull-requests-limit: 0
-  - package-ecosystem: "pip"
-    directory: "/"
-    schedule:
-      interval: "daily"
-    # Disable version updates for pip dependencies
-    open-pull-requests-limit: 0
diff --git a/dependencies.properties b/dependencies.properties
deleted file mode 100644
index 46ff94871..000000000
--- a/dependencies.properties
+++ /dev/null
@@ -1,83 +0,0 @@
-# This file is shared between gradle and bazel build scripts and exists to keep the dependencies
-# configuration between the two build systems in sync.
-
-# The properties format is the following:
-#   <dependency_type>.<artifact_name>=<value>
-
-# Target workspace name: com_google_api_gax_java
-
-# Versions of oneself
-# {x-version-update-start:gax:current}
-version.gax=2.20.1
-# {x-version-update-end}
-# {x-version-update-start:gax:current}
-version.gax_grpc=2.20.1
-# {x-version-update-end}
-# {x-version-update-start:gax:current}
-version.gax_bom=2.20.1
-# {x-version-update-end}
-# {x-version-update-start:gax-httpjson:current}
-version.gax_httpjson=0.105.1
-# {x-version-update-end}
-
-# Versions for dependencies which actual artifacts differ between Bazel and Gradle.
-# Gradle build depends on prebuilt maven artifacts, while Bazel build depends on Bazel workspaces
-# with the sources.
-version.com_google_protobuf=3.21.12
-version.google_java_format=1.15.0
-version.io_grpc=1.51.1
-
-# Maven artifacts.
-# Note, the actual name of each property matters (bazel build scripts depend on it).
-# It should be constructed the following way:
-#   1) Take full artifact id (including the group and classifier (if any) portions) and remove version portion.
-#   2) Replace all characters which are neither alphabetic nor digits with the underscore ('_') character
-maven.com_google_api_grpc_proto_google_common_protos=com.google.api.grpc:proto-google-common-protos:2.11.0
-maven.com_google_api_grpc_grpc_google_common_protos=com.google.api.grpc:grpc-google-common-protos:2.11.0
-maven.com_google_auth_google_auth_library_oauth2_http=com.google.auth:google-auth-library-oauth2-http:1.13.0
-maven.com_google_auth_google_auth_library_credentials=com.google.auth:google-auth-library-credentials:1.13.0
-maven.io_opencensus_opencensus_api=io.opencensus:opencensus-api:0.31.1
-maven.io_opencensus_opencensus_contrib_grpc_metrics=io.opencensus:opencensus-contrib-grpc-metrics:0.31.1
-maven.io_opencensus_opencensus_contrib_http_util=io.opencensus:opencensus-contrib-http-util:0.31.1
-maven.io_netty_netty_tcnative_boringssl_static=io.netty:netty-tcnative-boringssl-static:2.0.46.Final
-maven.io_netty_netty_handler=io.netty:netty-handler:4.1.72.Final
-maven.io_netty_netty_common=io.netty:netty-common:4.1.72.Final
-maven.io_netty_netty_codec_socks=io.netty:netty-codec-socks:4.1.72.Final
-maven.io_netty_netty_codec_http2=io.netty:netty-codec-http2:4.1.72.Final
-maven.io_netty_netty_codec_http=io.netty:netty-codec-http:4.1.72.Final
-maven.io_netty_netty_codec=io.netty:netty-codec:4.1.72.Final
-maven.io_netty_netty_buffer=io.netty:netty-buffer:4.1.72.Final
-maven.io_netty_netty_resolver=io.netty:netty-resolver:4.1.72.Final
-maven.io_netty_netty_transport=io.netty:netty-transport:4.1.72.Final
-maven.io_netty_netty_handler_proxy=io.netty:netty-handler-proxy:4.1.72.Final
-maven.io_netty_netty_transport_native_unix_common=io.netty:netty-transport-native-unix-common:4.1.72.Final
-maven.io_perfmark_perfmark_api=io.perfmark:perfmark-api:0.25.0
-maven.org_apache_tomcat_annotations_api=org.apache.tomcat:annotations-api:6.0.53
-maven.com_google_code_gson_gson=com.google.code.gson:gson:2.10
-maven.com_google_guava_guava=com.google.guava:guava:31.1-jre
-maven.com_google_guava_failureaccess=com.google.guava:failureaccess:1.0.1
-maven.org_apache_commons_commons_lang3=org.apache.commons:commons-lang3:3.8.1
-maven.com_google_android_annotations=com.google.android:annotations:4.1.1.4
-maven.com_google_code_findbugs_jsr305=com.google.code.findbugs:jsr305:3.0.2
-maven.com_google_errorprone_error_prone_annotations=com.google.errorprone:error_prone_annotations:2.11.0
-maven.com_google_j2objc_j2objc_annotations=com.google.j2objc:j2objc-annotations:1.3
-maven.com_google_auto_value_auto_value=com.google.auto.value:auto-value:1.10.1
-maven.com_google_auto_value_auto_value_annotations=com.google.auto.value:auto-value-annotations:1.10.1
-maven.com_google_api_api_common=com.google.api:api-common:2.3.1
-maven.org_threeten_threetenbp=org.threeten:threetenbp:1.6.4
-maven.com_google_api_grpc_grpc_google_iam_v1=com.google.api.grpc:grpc-google-iam-v1:1.4.0
-maven.com_google_api_grpc_proto_google_iam_v1=com.google.api.grpc:proto-google-iam-v1:1.4.0
-maven.com_google_http_client_google_http_client=com.google.http-client:google-http-client:1.42.3
-maven.com_google_http_client_google_http_client_gson=com.google.http-client:google-http-client-gson:1.42.3
-maven.org_codehaus_mojo_animal_sniffer_annotations=org.codehaus.mojo:animal-sniffer-annotations:1.18
-maven.javax_annotation_javax_annotation_api=javax.annotation:javax.annotation-api:1.3.2
-maven.org_graalvm_sdk=org.graalvm.sdk:graal-sdk:22.3.0
-
-# Testing maven artifacts
-maven.junit_junit=junit:junit:4.13.2
-maven.org_mockito_mockito_core=org.mockito:mockito-core:2.28.2
-maven.org_hamcrest_hamcrest_core=org.hamcrest:hamcrest-core:1.3
-maven.com_google_truth_truth=com.google.truth:truth:1.1.2
-maven.com_googlecode_java_diff_utils_diffutils=com.googlecode.java-diff-utils:diffutils:1.3.0
-maven.net_bytebuddy_byte_buddy=net.bytebuddy:byte-buddy:1.9.7
-maven.org_objenesis_objenesis=org.objenesis:objenesis:2.6
diff --git a/gax-bom/BUILD.bazel b/gax-bom/BUILD.bazel
deleted file mode 100644
index e69de29bb..000000000
diff --git a/gax-bom/build.gradle b/gax-bom/build.gradle
deleted file mode 100644
index 6dfd30ff5..000000000
--- a/gax-bom/build.gradle
+++ /dev/null
@@ -1,81 +0,0 @@
-plugins {
-  id 'maven-publish'
-  id 'signing'
-}
-
-archivesBaseName = 'gax-bom'
-
-project.version = "2.20.1" // {x-version-update:gax-bom:current}
-
-def mavenJavaDir = "$buildDir/publications/mavenJava"
-def mavenJavaBomOutputFile = file(mavenJavaDir + '/pom-default.xml')
-def mavenJavaBomAscOutputFile = file(mavenJavaDir + '/pom-default.xml.asc')
-
-// Copy our pom.xml to the location where a generated POM would go
-task copyPom() {
-  doLast {
-    new File(mavenJavaDir).mkdirs()
-    copy {
-      from 'pom.xml'
-      into mavenJavaDir
-      rename 'pom.xml', 'pom-default.xml'
-    }
-  }
-}
-
-// We want to use our own pom.xml instead of the generated one, so we disable
-// the pom.xml generation and have the publish tasks depend on `copyPom` instead.
-tasks.whenTaskAdded { task ->
-  if (task.name == 'generatePomFileForMavenJavaPublication') {
-    task.enabled = false
-  } else if (task.name == 'publishMavenJavaPublicationToMavenLocal') {
-    task.dependsOn copyPom
-  } else if (task.name == 'publishMavenJavaPublicationToMavenRepository') {
-    task.dependsOn copyPom
-  } else if (task.name == 'publishMavenJavaPublicationToSonatypeRepository') {
-    task.dependsOn copyPom
-  }
-}
-
-// We can't use the `publishing` section from the main build.gradle because
-// we don't want all the Java artifacts, and we want to use our own pom.xml
-// instead of the generated one.
-publishing {
-  publications {
-    mavenJava(MavenPublication) {
-      version = project.version
-      artifact mavenJavaBomOutputFile
-    }
-  }
-  repositories {
-    maven {
-      url 'https://google.oss.sonatype.org/service/local/staging/deploy/maven2/'
-      credentials {
-        username = findProperty('ossrhUsername')
-        password = findProperty('ossrhPassword')
-      }
-    }
-  }
-}
-
-signing {
-  required { gradle.taskGraph.hasTask ":${name}:publishToSonatype" }
-  if (project.hasProperty('signing.gnupg.executable')) {
-    useGpgCmd()
-  }
-  sign publishing.publications
-}
-
-// Unlike other regular subprojects, pom.asc (signature file) generated by
-// signing is not automatically picked up. It may be because gax-bom uses a
-// pre-written pom.xml instead of using an auto-generated one.
-// https://discuss.gradle.org/t/how-to-publish-artifacts-signatures-asc-files-using-maven-publish-plugin/7422
-task addPomAscFileToPublication {
-  onlyIf { mavenJavaBomAscOutputFile.exists() }
-  doLast {
-    publishing.publications.mavenJava(MavenPublication) {
-      artifact(mavenJavaBomAscOutputFile) { extension 'pom.asc' }
-    }
-  }
-}
-signMavenJavaPublication.finalizedBy addPomAscFileToPublication
diff --git a/gax-bom/pom.xml b/gax-bom/pom.xml
deleted file mode 100644
index 1681cf4f9..000000000
--- a/gax-bom/pom.xml
+++ /dev/null
@@ -1,103 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <groupId>com.google.api</groupId>
-  <artifactId>gax-bom</artifactId>
-  <version>2.20.1</version><!-- {x-version-update:gax-bom:current} -->
-  <packaging>pom</packaging>
-  <name>GAX (Google Api eXtensions) for Java (BOM)</name>
-  <description>Google Api eXtensions for Java (BOM)</description>
-
-  <parent>
-    <groupId>com.google.cloud</groupId>
-    <artifactId>google-cloud-shared-config</artifactId>
-    <version>1.5.5</version>
-  </parent>
-
-  <developers>
-    <developer>
-      <id>GoogleAPIs</id>
-      <name>GoogleAPIs</name>
-      <email>googleapis@googlegroups.com</email>
-      <url>https://github.com/googleapis/gax-java</url>
-      <organization>Google, LLC</organization>
-      <organizationUrl>https://www.google.com</organizationUrl>
-    </developer>
-  </developers>
-
-  <scm>
-    <connection>scm:git:https://github.com/googleapis/gax-java.git</connection>
-    <url>https://github.com/googleapis/gax-java</url>
-  </scm>
-
-  <licenses>
-    <license>
-      <name>BSD</name>
-      <url>https://github.com/googleapis/gax-java/blob/master/LICENSE</url>
-    </license>
-  </licenses>
-
-  <dependencyManagement>
-    <dependencies>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax</artifactId>
-        <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax</artifactId>
-        <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-        <classifier>testlib</classifier>
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax-grpc</artifactId>
-        <version>2.20.1</version><!-- {x-version-update:gax-grpc:current} -->
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax-grpc</artifactId>
-        <version>2.20.1</version><!-- {x-version-update:gax-grpc:current} -->
-        <classifier>testlib</classifier>
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax-httpjson</artifactId>
-        <version>0.105.1</version><!-- {x-version-update:gax-httpjson:current} -->
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax-httpjson</artifactId>
-        <version>0.105.1</version><!-- {x-version-update:gax-httpjson:current} -->
-        <classifier>testlib</classifier>
-      </dependency>
-    </dependencies>
-  </dependencyManagement>
-
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-checkstyle-plugin</artifactId>
-        <configuration>
-          <skip>true</skip>
-        </configuration>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <executions>
-          <execution>
-            <goals>
-              <goal>test-jar</goal>
-            </goals>
-            <configuration>
-              <skip>true</skip>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
-</project>
diff --git a/gax-grpc/BUILD.bazel b/gax-grpc/BUILD.bazel
deleted file mode 100644
index f1dfe02fc..000000000
--- a/gax-grpc/BUILD.bazel
+++ /dev/null
@@ -1,89 +0,0 @@
-load("//:gax_java.bzl", "google_java_format", "google_java_format_verification", "java_tests")
-
-_JAVA_COPTS = [
-    "-source",
-    "1.8",
-    "-target",
-    "1.8",
-]
-
-_COMPILE_DEPS = [
-    "@io_grpc_grpc_java//core:core",
-    "@io_grpc_grpc_java//stub:stub",
-    "@io_grpc_grpc_java//auth:auth",
-    "@io_grpc_grpc_java//protobuf:protobuf",
-    "@com_google_protobuf//:protobuf_java",
-    "@com_google_guava_guava//jar",
-    "@com_google_code_findbugs_jsr305//jar",
-    "@com_google_code_gson_gson//jar",
-    "@org_threeten_threetenbp//jar",
-    "@com_google_auth_google_auth_library_oauth2_http//jar",
-    "@com_google_auth_google_auth_library_credentials//jar",
-    "@com_google_api_grpc_proto_google_common_protos//jar",
-    "@com_google_api_api_common//jar",
-    "@com_google_auto_value_auto_value//jar",
-    "@com_google_auto_value_auto_value_annotations//jar",
-    "@com_google_http_client_google_http_client//jar",
-    "@io_grpc_grpc_java//context:context",
-    "@io_grpc_grpc_netty_shaded//jar",
-    "@io_grpc_grpc_grpclb//jar",
-    "@io_grpc_grpc_java//alts:alts",
-    "@io_netty_netty_tcnative_boringssl_static//jar",
-    "@javax_annotation_javax_annotation_api//jar",
-    "//gax:gax",
-    "@org_graalvm_sdk//jar"
-]
-
-_TEST_COMPILE_DEPS = [
-    "@junit_junit//jar",
-    "@org_mockito_mockito_core//jar",
-    "@com_google_truth_truth//jar",
-    "@io_grpc_grpc_java//core:inprocess",
-    "@com_google_api_grpc_grpc_google_common_protos//jar",
-    "//gax:gax_testlib",
-    "@com_googlecode_java_diff_utils_diffutils//jar",
-]
-
-java_library(
-    name = "gax_grpc",
-    srcs = glob(["src/main/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    resources = ["//:dependencies.properties"],
-    visibility = ["//visibility:public"],
-    deps = _COMPILE_DEPS,
-)
-
-java_library(
-    name = "gax_grpc_testlib",
-    srcs = glob(["src/test/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    visibility = ["//visibility:public"],
-    deps = [":gax_grpc"] + _COMPILE_DEPS + _TEST_COMPILE_DEPS,
-)
-
-java_tests(
-    name = "gax_grpc_tests",
-    size = "small",
-    srcs = glob(
-        include = ["src/test/java/**/*Test.java"],
-        exclude = [
-            "src/test/java/**/Abstract*Test.java",
-        ],
-    ),
-    runtime_deps = [":gax_grpc_testlib"],
-)
-
-google_java_format(
-    name = "google_java_format",
-    srcs = glob(["src/**/*.java"]),
-    formatter = "//:google_java_format_binary",
-)
-
-#Uncomment once java formatter is upgraded to 1.6+
-#google_java_format_verification(
-#    name = "google_java_format_verification",
-#    srcs = glob(["src/**/*.java"]),
-#    formatter = "//:google_java_format_binary",
-#)
diff --git a/gax-grpc/build.gradle b/gax-grpc/build.gradle
deleted file mode 100644
index 5c5c86807..000000000
--- a/gax-grpc/build.gradle
+++ /dev/null
@@ -1,50 +0,0 @@
-archivesBaseName = 'gax-grpc'
-
-// TODO: Populate this from dependencies.properties version property (for proper Gradle-Bazel sync)
-project.version = "2.20.1" // {x-version-update:gax-grpc:current}
-
-dependencies {
-  api(project(':gax'),
-    libraries['maven.com_google_api_api_common'],
-    libraries['maven.com_google_api_grpc_proto_google_common_protos'],
-    libraries['maven.com_google_auth_google_auth_library_credentials'],
-    libraries['maven.com_google_guava_guava'],
-    libraries['maven.io_grpc_grpc_api'],
-    libraries['maven.org_threeten_threetenbp'])
-
-  implementation(libraries['maven.com_google_auth_google_auth_library_oauth2_http'],
-    libraries['maven.com_google_code_findbugs_jsr305'],
-    libraries['maven.io_grpc_grpc_alts'],
-    libraries['maven.io_grpc_grpc_auth'],
-    libraries['maven.io_grpc_grpc_netty_shaded'],
-    libraries['maven.io_grpc_grpc_protobuf'],
-    libraries['maven.io_grpc_grpc_stub'])
-
-  runtimeOnly libraries['maven.io_grpc_grpc_googleapis']
-
-  compileOnly(libraries['maven.com_google_auto_value_auto_value'],
-          libraries['maven.org_graalvm_sdk'])
-
-  testImplementation( project(':gax').sourceSets.test.output,
-    libraries['maven.junit_junit'],
-    libraries['maven.org_mockito_mockito_core'],
-    libraries['maven.com_google_truth_truth'],
-    libraries['maven.com_google_api_grpc_grpc_google_common_protos'])
-
-  annotationProcessor libraries['maven.com_google_auto_value_auto_value']
-
-  shadowNoGuava libraries['maven.com_google_guava_guava'],
-    libraries['maven.io_grpc_grpc_stub'],
-    libraries['maven.io_grpc_grpc_protobuf']
-}
-
-jar {
-  manifest {
-    attributes 'Specification-Title': project.name,
-      'Specification-Version': project.version,
-      'Specification-Vendor': libraryVendor,
-      'Implementation-Title': project.name,
-      'Implementation-Version': project.version,
-      'Implementation-Vendor': libraryVendor
-  }
-}
diff --git a/gax-grpc/pom.xml b/gax-grpc/pom.xml
deleted file mode 100644
index ad7addccd..000000000
--- a/gax-grpc/pom.xml
+++ /dev/null
@@ -1,129 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <artifactId>gax-grpc</artifactId>
-  <version>2.20.1</version><!-- {x-version-update:gax-grpc:current} -->
-  <packaging>jar</packaging>
-  <name>GAX (Google Api eXtensions) for Java (gRPC)</name>
-  <description>Google Api eXtensions for Java (gRPC)</description>
-
-  <parent>
-    <groupId>com.google.api</groupId>
-    <artifactId>gax-parent</artifactId>
-    <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-  </parent>
-
-  <dependencies>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>gax</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>api-common</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api.grpc</groupId>
-      <artifactId>proto-google-common-protos</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-credentials</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.guava</groupId>
-      <artifactId>guava</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-api</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>org.threeten</groupId>
-      <artifactId>threetenbp</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-oauth2-http</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-alts</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-auth</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-protobuf</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-stub</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-netty-shaded</artifactId>
-      <scope>runtime</scope>
-    </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-googleapis</artifactId>
-      <scope>runtime</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.google.code.findbugs</groupId>
-      <artifactId>jsr305</artifactId>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.graalvm.sdk</groupId>
-      <artifactId>graal-sdk</artifactId>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auto.value</groupId>
-      <artifactId>auto-value-annotations</artifactId>
-      <scope>provided</scope>
-    </dependency>
-
-    <!-- test dependencies -->
-    <dependency>
-      <groupId>com.google.api.grpc</groupId>
-      <artifactId>grpc-google-common-protos</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>gax</artifactId>
-      <type>test-jar</type>
-      <scope>test</scope>
-      <classifier>testlib</classifier>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <executions>
-          <execution>
-            <goals>
-              <goal>test-jar</goal>
-            </goals>
-            <configuration>
-              <skip>false</skip>
-              <classifier>testlib</classifier>
-              <includes>
-                <include>com/google/api/gax/grpc/testing/**</include>
-              </includes>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
-</project>
\ No newline at end of file
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ApiStreamObserverDelegate.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ApiStreamObserverDelegate.java
deleted file mode 100644
index c19818751..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ApiStreamObserverDelegate.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiStreamObserver;
-import io.grpc.stub.StreamObserver;
-
-/**
- * A delegate class that transfers calls to the ApiStreamObserver object.
- *
- * <p>Package-private for internal use.
- */
-class ApiStreamObserverDelegate<V> implements StreamObserver<V> {
-
-  private final ApiStreamObserver<V> delegate;
-
-  public ApiStreamObserverDelegate(ApiStreamObserver<V> delegate) {
-    this.delegate = delegate;
-  }
-
-  @Override
-  public void onNext(V v) {
-    delegate.onNext(v);
-  }
-
-  @Override
-  public void onError(Throwable throwable) {
-    delegate.onError(throwable);
-  }
-
-  @Override
-  public void onCompleted() {
-    delegate.onCompleted();
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/CallOptionsUtil.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/CallOptionsUtil.java
deleted file mode 100644
index f36da0d4d..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/CallOptionsUtil.java
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import io.grpc.CallOptions;
-import io.grpc.Metadata;
-import io.grpc.Metadata.Key;
-import java.util.Collections;
-import java.util.Map;
-
-/** A utility class that provides helper functions to work with custom call options. */
-class CallOptionsUtil {
-  // this is a call option name, not a header name, it is not transferred over the wire
-  private static final CallOptions.Key<Map<Key<String>, String>> DYNAMIC_HEADERS_CALL_OPTION_KEY =
-      CallOptions.Key.createWithDefault(
-          "gax_dynamic_headers", Collections.<Key<String>, String>emptyMap());
-  // this is the header name, it is transferred over the wire
-  static Metadata.Key<String> REQUEST_PARAMS_HEADER_KEY =
-      Metadata.Key.of("x-goog-request-params", Metadata.ASCII_STRING_MARSHALLER);
-  private static final CallOptions.Key<ResponseMetadataHandler> METADATA_HANDLER_CALL_OPTION_KEY =
-      CallOptions.Key.createWithDefault("gax_metadata_handler", null);
-
-  private CallOptionsUtil() {}
-
-  static CallOptions putRequestParamsDynamicHeaderOption(
-      CallOptions callOptions, String requestParams) {
-    if (callOptions == null || requestParams.isEmpty()) {
-      return callOptions;
-    }
-
-    Map<Key<String>, String> dynamicHeadersOption =
-        callOptions.getOption(DYNAMIC_HEADERS_CALL_OPTION_KEY);
-
-    // This will fail, if REQUEST_PARAMS_HEADER_KEY is already there
-    dynamicHeadersOption =
-        ImmutableMap.<Key<String>, String>builder()
-            .putAll(dynamicHeadersOption)
-            .put(REQUEST_PARAMS_HEADER_KEY, requestParams)
-            .build();
-
-    return callOptions.withOption(DYNAMIC_HEADERS_CALL_OPTION_KEY, dynamicHeadersOption);
-  }
-
-  static Map<Key<String>, String> getDynamicHeadersOption(CallOptions callOptions) {
-    return callOptions.getOption(DYNAMIC_HEADERS_CALL_OPTION_KEY);
-  }
-
-  static CallOptions putMetadataHandlerOption(
-      CallOptions callOptions, ResponseMetadataHandler handler) {
-    Preconditions.checkNotNull(callOptions);
-    Preconditions.checkNotNull(handler);
-    return callOptions.withOption(METADATA_HANDLER_CALL_OPTION_KEY, handler);
-  }
-
-  public static ResponseMetadataHandler getMetadataHandlerOption(CallOptions callOptions) {
-    return callOptions.getOption(METADATA_HANDLER_CALL_OPTION_KEY);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelFactory.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelFactory.java
deleted file mode 100644
index 416ce4469..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelFactory.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import io.grpc.ManagedChannel;
-import java.io.IOException;
-
-/**
- * This interface represents a factory for creating one ManagedChannel
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi("For internal use by google-cloud-java clients only")
-public interface ChannelFactory {
-  ManagedChannel createSingleChannel() throws IOException;
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPool.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPool.java
deleted file mode 100644
index 5215b4d9b..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPool.java
+++ /dev/null
@@ -1,548 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ForwardingClientCall.SimpleForwardingClientCall;
-import io.grpc.ForwardingClientCallListener.SimpleForwardingClientCallListener;
-import io.grpc.ManagedChannel;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicReference;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import org.threeten.bp.Duration;
-
-/**
- * A {@link ManagedChannel} that will send requests round-robin via a set of channels.
- *
- * <p>In addition to spreading requests over a set of child connections, the pool will also actively
- * manage the lifecycle of the channels. Currently lifecycle management is limited to pre-emptively
- * replacing channels every hour. In the future it will dynamically size the pool based on number of
- * outstanding requests.
- *
- * <p>Package-private for internal use.
- */
-class ChannelPool extends ManagedChannel {
-  private static final Logger LOG = Logger.getLogger(ChannelPool.class.getName());
-  private static final Duration REFRESH_PERIOD = Duration.ofMinutes(50);
-
-  private final ChannelPoolSettings settings;
-  private final ChannelFactory channelFactory;
-  private final ScheduledExecutorService executor;
-
-  private final Object entryWriteLock = new Object();
-  @VisibleForTesting final AtomicReference<ImmutableList<Entry>> entries = new AtomicReference<>();
-  private final AtomicInteger indexTicker = new AtomicInteger();
-  private final String authority;
-
-  static ChannelPool create(ChannelPoolSettings settings, ChannelFactory channelFactory)
-      throws IOException {
-    return new ChannelPool(settings, channelFactory, Executors.newSingleThreadScheduledExecutor());
-  }
-
-  /**
-   * Initializes the channel pool. Assumes that all channels have the same authority.
-   *
-   * @param settings options for controling the ChannelPool sizing behavior
-   * @param channelFactory method to create the channels
-   * @param executor periodically refreshes the channels
-   */
-  @VisibleForTesting
-  ChannelPool(
-      ChannelPoolSettings settings,
-      ChannelFactory channelFactory,
-      ScheduledExecutorService executor)
-      throws IOException {
-    this.settings = settings;
-    this.channelFactory = channelFactory;
-
-    ImmutableList.Builder<Entry> initialListBuilder = ImmutableList.builder();
-
-    for (int i = 0; i < settings.getInitialChannelCount(); i++) {
-      initialListBuilder.add(new Entry(channelFactory.createSingleChannel()));
-    }
-
-    entries.set(initialListBuilder.build());
-    authority = entries.get().get(0).channel.authority();
-    this.executor = executor;
-
-    if (!settings.isStaticSize()) {
-      executor.scheduleAtFixedRate(
-          this::resizeSafely,
-          ChannelPoolSettings.RESIZE_INTERVAL.getSeconds(),
-          ChannelPoolSettings.RESIZE_INTERVAL.getSeconds(),
-          TimeUnit.SECONDS);
-    }
-    if (settings.isPreemptiveRefreshEnabled()) {
-      executor.scheduleAtFixedRate(
-          this::refreshSafely,
-          REFRESH_PERIOD.getSeconds(),
-          REFRESH_PERIOD.getSeconds(),
-          TimeUnit.SECONDS);
-    }
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public String authority() {
-    return authority;
-  }
-
-  /**
-   * Create a {@link ClientCall} on a Channel from the pool chosen in a round-robin fashion to the
-   * remote operation specified by the given {@link MethodDescriptor}. The returned {@link
-   * ClientCall} does not trigger any remote behavior until {@link
-   * ClientCall#start(ClientCall.Listener, io.grpc.Metadata)} is invoked.
-   */
-  @Override
-  public <ReqT, RespT> ClientCall<ReqT, RespT> newCall(
-      MethodDescriptor<ReqT, RespT> methodDescriptor, CallOptions callOptions) {
-    return getChannel(indexTicker.getAndIncrement()).newCall(methodDescriptor, callOptions);
-  }
-
-  Channel getChannel(int affinity) {
-    return new AffinityChannel(affinity);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public ManagedChannel shutdown() {
-    List<Entry> localEntries = entries.get();
-    for (Entry entry : localEntries) {
-      entry.channel.shutdown();
-    }
-    if (executor != null) {
-      // shutdownNow will cancel scheduled tasks
-      executor.shutdownNow();
-    }
-    return this;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public boolean isShutdown() {
-    List<Entry> localEntries = entries.get();
-    for (Entry entry : localEntries) {
-      if (!entry.channel.isShutdown()) {
-        return false;
-      }
-    }
-    return executor == null || executor.isShutdown();
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public boolean isTerminated() {
-    List<Entry> localEntries = entries.get();
-    for (Entry entry : localEntries) {
-      if (!entry.channel.isTerminated()) {
-        return false;
-      }
-    }
-
-    return executor == null || executor.isTerminated();
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public ManagedChannel shutdownNow() {
-    List<Entry> localEntries = entries.get();
-    for (Entry entry : localEntries) {
-      entry.channel.shutdownNow();
-    }
-    if (executor != null) {
-      executor.shutdownNow();
-    }
-    return this;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
-    long endTimeNanos = System.nanoTime() + unit.toNanos(timeout);
-    List<Entry> localEntries = entries.get();
-    for (Entry entry : localEntries) {
-      long awaitTimeNanos = endTimeNanos - System.nanoTime();
-      if (awaitTimeNanos <= 0) {
-        break;
-      }
-      entry.channel.awaitTermination(awaitTimeNanos, TimeUnit.NANOSECONDS);
-    }
-    if (executor != null) {
-      long awaitTimeNanos = endTimeNanos - System.nanoTime();
-      executor.awaitTermination(awaitTimeNanos, TimeUnit.NANOSECONDS);
-    }
-    return isTerminated();
-  }
-
-  private void resizeSafely() {
-    try {
-      synchronized (entryWriteLock) {
-        resize();
-      }
-    } catch (Exception e) {
-      LOG.log(Level.WARNING, "Failed to resize channel pool", e);
-    }
-  }
-
-  /**
-   * Resize the number of channels based on the number of outstanding RPCs.
-   *
-   * <p>This method is expected to be called on a fixed interval. On every invocation it will:
-   *
-   * <ul>
-   *   <li>Get the maximum number of outstanding RPCs since last invocation
-   *   <li>Determine a valid range of number of channels to handle that many outstanding RPCs
-   *   <li>If the current number of channel falls outside of that range, add or remove at most
-   *       {@link ChannelPoolSettings#MAX_RESIZE_DELTA} to get closer to middle of that range.
-   * </ul>
-   *
-   * <p>Not threadsafe, must be called under the entryWriteLock monitor
-   */
-  @VisibleForTesting
-  void resize() {
-    List<Entry> localEntries = entries.get();
-    // Estimate the peak of RPCs in the last interval by summing the peak of RPCs per channel
-    int actualOutstandingRpcs =
-        localEntries.stream().mapToInt(Entry::getAndResetMaxOutstanding).sum();
-
-    // Number of channels if each channel operated at max capacity
-    int minChannels =
-        (int) Math.ceil(actualOutstandingRpcs / (double) settings.getMaxRpcsPerChannel());
-    // Limit the threshold to absolute range
-    if (minChannels < settings.getMinChannelCount()) {
-      minChannels = settings.getMinChannelCount();
-    }
-
-    // Number of channels if each channel operated at minimum capacity
-    // Note: getMinRpcsPerChannel() can return 0, but division by 0 shouldn't cause a problem.
-    int maxChannels =
-        (int) Math.ceil(actualOutstandingRpcs / (double) settings.getMinRpcsPerChannel());
-    // Limit the threshold to absolute range
-    if (maxChannels > settings.getMaxChannelCount()) {
-      maxChannels = settings.getMaxChannelCount();
-    }
-    if (maxChannels < minChannels) {
-      maxChannels = minChannels;
-    }
-
-    // If the pool were to be resized, try to aim for the middle of the bound, but limit rate of
-    // change.
-    int tentativeTarget = (maxChannels + minChannels) / 2;
-    int currentSize = localEntries.size();
-    int delta = tentativeTarget - currentSize;
-    int dampenedTarget = tentativeTarget;
-    if (Math.abs(delta) > ChannelPoolSettings.MAX_RESIZE_DELTA) {
-      dampenedTarget =
-          currentSize + (int) Math.copySign(ChannelPoolSettings.MAX_RESIZE_DELTA, delta);
-    }
-
-    // Only resize the pool when thresholds are crossed
-    if (localEntries.size() < minChannels) {
-      LOG.fine(
-          String.format(
-              "Detected throughput peak of %d, expanding channel pool size: %d -> %d.",
-              actualOutstandingRpcs, currentSize, dampenedTarget));
-
-      expand(dampenedTarget);
-    } else if (localEntries.size() > maxChannels) {
-      LOG.fine(
-          String.format(
-              "Detected throughput drop to %d, shrinking channel pool size: %d -> %d.",
-              actualOutstandingRpcs, currentSize, dampenedTarget));
-
-      shrink(dampenedTarget);
-    }
-  }
-
-  /** Not threadsafe, must be called under the entryWriteLock monitor */
-  private void shrink(int desiredSize) {
-    ImmutableList<Entry> localEntries = entries.get();
-    Preconditions.checkState(
-        localEntries.size() >= desiredSize, "current size is already smaller than the desired");
-
-    // Set the new list
-    entries.set(localEntries.subList(0, desiredSize));
-    // clean up removed entries
-    List<Entry> removed = localEntries.subList(desiredSize, localEntries.size());
-    removed.forEach(Entry::requestShutdown);
-  }
-
-  /** Not threadsafe, must be called under the entryWriteLock monitor */
-  private void expand(int desiredSize) {
-    List<Entry> localEntries = entries.get();
-    Preconditions.checkState(
-        localEntries.size() <= desiredSize, "current size is already bigger than the desired");
-
-    ImmutableList.Builder<Entry> newEntries = ImmutableList.<Entry>builder().addAll(localEntries);
-
-    for (int i = 0; i < desiredSize - localEntries.size(); i++) {
-      try {
-        newEntries.add(new Entry(channelFactory.createSingleChannel()));
-      } catch (IOException e) {
-        LOG.log(Level.WARNING, "Failed to add channel", e);
-      }
-    }
-
-    entries.set(newEntries.build());
-  }
-
-  private void refreshSafely() {
-    try {
-      refresh();
-    } catch (Exception e) {
-      LOG.log(Level.WARNING, "Failed to pre-emptively refresh channnels", e);
-    }
-  }
-
-  /**
-   * Replace all of the channels in the channel pool with fresh ones. This is meant to mitigate the
-   * hourly GFE disconnects by giving clients the ability to prime the channel on reconnect.
-   *
-   * <p>This is done on a best effort basis. If the replacement channel fails to construct, the old
-   * channel will continue to be used.
-   */
-  @InternalApi("Visible for testing")
-  void refresh() {
-    // Note: synchronization is necessary in case refresh is called concurrently:
-    // - thread1 fails to replace a single entry
-    // - thread2 succeeds replacing an entry
-    // - thread1 loses the race to replace the list
-    // - then thread2 will shut down channel that thread1 will put back into circulation (after it
-    //   replaces the list)
-    synchronized (entryWriteLock) {
-      ArrayList<Entry> newEntries = new ArrayList<>(entries.get());
-
-      for (int i = 0; i < newEntries.size(); i++) {
-        try {
-          newEntries.set(i, new Entry(channelFactory.createSingleChannel()));
-        } catch (IOException e) {
-          LOG.log(Level.WARNING, "Failed to refresh channel, leaving old channel", e);
-        }
-      }
-
-      ImmutableList<Entry> replacedEntries = entries.getAndSet(ImmutableList.copyOf(newEntries));
-
-      // Shutdown the channels that were cycled out.
-      for (Entry e : replacedEntries) {
-        if (!newEntries.contains(e)) {
-          e.requestShutdown();
-        }
-      }
-    }
-  }
-
-  /**
-   * Get and retain a Channel Entry. The returned Entry will have its rpc count incremented,
-   * preventing it from getting recycled.
-   */
-  Entry getRetainedEntry(int affinity) {
-    // The maximum number of concurrent calls to this method for any given time span is at most 2,
-    // so the loop can actually be 2 times. But going for 5 times for a safety margin for potential
-    // code evolving
-    for (int i = 0; i < 5; i++) {
-      Entry entry = getEntry(affinity);
-      if (entry.retain()) {
-        return entry;
-      }
-    }
-    // It is unlikely to reach here unless the pool code evolves to increase the maximum possible
-    // concurrent calls to this method. If it does, this is a bug in the channel pool implementation
-    // the number of retries above should be greater than the number of contending maintenance
-    // tasks.
-    throw new IllegalStateException("Bug: failed to retain a channel");
-  }
-
-  /**
-   * Returns one of the channels managed by this pool. The pool continues to "own" the channel, and
-   * the caller should not shut it down.
-   *
-   * @param affinity Two calls to this method with the same affinity returns the same channel most
-   *     of the time, if the channel pool was refreshed since the last call, a new channel will be
-   *     returned. The reverse is not true: Two calls with different affinities might return the
-   *     same channel. However, the implementation should attempt to spread load evenly.
-   */
-  private Entry getEntry(int affinity) {
-    List<Entry> localEntries = entries.get();
-
-    int index = Math.abs(affinity % localEntries.size());
-
-    return localEntries.get(index);
-  }
-
-  /** Bundles a gRPC {@link ManagedChannel} with some usage accounting. */
-  private static class Entry {
-    private final ManagedChannel channel;
-    private final AtomicInteger outstandingRpcs = new AtomicInteger(0);
-    private final AtomicInteger maxOutstanding = new AtomicInteger();
-
-    // Flag that the channel should be closed once all of the outstanding RPC complete.
-    private final AtomicBoolean shutdownRequested = new AtomicBoolean();
-    // Flag that the channel has been closed.
-    private final AtomicBoolean shutdownInitiated = new AtomicBoolean();
-
-    private Entry(ManagedChannel channel) {
-      this.channel = channel;
-    }
-
-    int getAndResetMaxOutstanding() {
-      return maxOutstanding.getAndSet(outstandingRpcs.get());
-    }
-
-    /**
-     * Try to increment the outstanding RPC count. The method will return false if the channel is
-     * closing and the caller should pick a different channel. If the method returned true, the
-     * channel has been successfully retained and it is the responsibility of the caller to release
-     * it.
-     */
-    private boolean retain() {
-      // register desire to start RPC
-      int currentOutstanding = outstandingRpcs.incrementAndGet();
-
-      // Rough book keeping
-      int prevMax = maxOutstanding.get();
-      if (currentOutstanding > prevMax) {
-        maxOutstanding.incrementAndGet();
-      }
-
-      // abort if the channel is closing
-      if (shutdownRequested.get()) {
-        release();
-        return false;
-      }
-      return true;
-    }
-
-    /**
-     * Notify the channel that the number of outstanding RPCs has decreased. If shutdown has been
-     * previously requested, this method will shutdown the channel if its the last outstanding RPC.
-     */
-    private void release() {
-      int newCount = outstandingRpcs.decrementAndGet();
-      if (newCount < 0) {
-        throw new IllegalStateException("Bug: reference count is negative!: " + newCount);
-      }
-
-      // Must check outstandingRpcs after shutdownRequested (in reverse order of retain()) to ensure
-      // mutual exclusion.
-      if (shutdownRequested.get() && outstandingRpcs.get() == 0) {
-        shutdown();
-      }
-    }
-
-    /**
-     * Request a shutdown. The actual shutdown will be delayed until there are no more outstanding
-     * RPCs.
-     */
-    private void requestShutdown() {
-      shutdownRequested.set(true);
-      if (outstandingRpcs.get() == 0) {
-        shutdown();
-      }
-    }
-
-    /** Ensure that shutdown is only called once. */
-    private void shutdown() {
-      if (shutdownInitiated.compareAndSet(false, true)) {
-        channel.shutdown();
-      }
-    }
-  }
-
-  /** Thin wrapper to ensure that new calls are properly reference counted. */
-  private class AffinityChannel extends Channel {
-    private final int affinity;
-
-    public AffinityChannel(int affinity) {
-      this.affinity = affinity;
-    }
-
-    @Override
-    public String authority() {
-      return authority;
-    }
-
-    @Override
-    public <RequestT, ResponseT> ClientCall<RequestT, ResponseT> newCall(
-        MethodDescriptor<RequestT, ResponseT> methodDescriptor, CallOptions callOptions) {
-
-      Entry entry = getRetainedEntry(affinity);
-
-      return new ReleasingClientCall<>(entry.channel.newCall(methodDescriptor, callOptions), entry);
-    }
-  }
-
-  /** ClientCall wrapper that makes sure to decrement the outstanding RPC count on completion. */
-  static class ReleasingClientCall<ReqT, RespT> extends SimpleForwardingClientCall<ReqT, RespT> {
-    final Entry entry;
-
-    public ReleasingClientCall(ClientCall<ReqT, RespT> delegate, Entry entry) {
-      super(delegate);
-      this.entry = entry;
-    }
-
-    @Override
-    public void start(Listener<RespT> responseListener, Metadata headers) {
-      try {
-        super.start(
-            new SimpleForwardingClientCallListener<RespT>(responseListener) {
-              @Override
-              public void onClose(Status status, Metadata trailers) {
-                try {
-                  super.onClose(status, trailers);
-                } finally {
-                  entry.release();
-                }
-              }
-            },
-            headers);
-      } catch (Exception e) {
-        // In case start failed, make sure to release
-        entry.release();
-      }
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPoolSettings.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPoolSettings.java
deleted file mode 100644
index 19e62782a..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPoolSettings.java
+++ /dev/null
@@ -1,183 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.grpc;
-
-import com.google.api.core.BetaApi;
-import com.google.auto.value.AutoValue;
-import com.google.common.base.Preconditions;
-import java.time.Duration;
-
-/**
- * Settings to control {@link ChannelPool} behavior.
- *
- * <p>To facilitate low latency/high throughout applications, gax provides a {@link ChannelPool}.
- * The pool is meant to facilitate high throughput/low latency clients. By splitting load across
- * multiple gRPC channels the client can spread load across multiple frontends and overcome gRPC's
- * limit of 100 concurrent RPCs per channel. However oversizing the {@link ChannelPool} can lead to
- * underutilized channels which will lead to high tail latency due to GFEs disconnecting idle
- * channels.
- *
- * <p>The {@link ChannelPool} is designed to adapt to varying traffic patterns by tracking
- * outstanding RPCs and resizing the pool size. This class configures the behavior. In general
- * clients should aim to have less than 50 concurrent RPCs per channel and at least 1 outstanding
- * per channel per minute.
- *
- * <p>The settings in this class will be applied every minute.
- */
-@BetaApi("surface for channel pool sizing is not yet stable")
-@AutoValue
-public abstract class ChannelPoolSettings {
-  /** How often to check and possibly resize the {@link ChannelPool}. */
-  static final Duration RESIZE_INTERVAL = Duration.ofMinutes(1);
-  /** The maximum number of channels that can be added or removed at a time. */
-  static final int MAX_RESIZE_DELTA = 2;
-
-  /**
-   * Threshold to start scaling down the channel pool.
-   *
-   * <p>When the average of the maximum number of outstanding RPCs in a single minute drop below
-   * this threshold, channels will be removed from the pool.
-   */
-  public abstract int getMinRpcsPerChannel();
-
-  /**
-   * Threshold to start scaling up the channel pool.
-   *
-   * <p>When the average of the maximum number of outstanding RPCs in a single minute surpass this
-   * threshold, channels will be added to the pool. For google services, gRPC channels will start
-   * locally queuing RPC when there are 100 concurrent RPCs.
-   */
-  public abstract int getMaxRpcsPerChannel();
-
-  /**
-   * The absolute minimum size of the channel pool.
-   *
-   * <p>Regardless of the current throughput, the number of channels will not drop below this limit
-   */
-  public abstract int getMinChannelCount();
-
-  /**
-   * The absolute maximum size of the channel pool.
-   *
-   * <p>Regardless of the current throughput, the number of channels will not exceed this limit
-   */
-  public abstract int getMaxChannelCount();
-
-  /**
-   * The initial size of the channel pool.
-   *
-   * <p>During client construction the client open this many connections. This will be scaled up or
-   * down in the next period.
-   */
-  public abstract int getInitialChannelCount();
-
-  /**
-   * If all of the channels should be replaced on an hourly basis.
-   *
-   * <p>The GFE will forcibly disconnect active channels after an hour. To minimize the cost of
-   * reconnects, this will create a new channel asynchronuously, prime it and then swap it with an
-   * old channel.
-   */
-  public abstract boolean isPreemptiveRefreshEnabled();
-
-  /** Helper to check if the {@link ChannelPool} implementation can skip dynamic size logic */
-  boolean isStaticSize() {
-    // When range is restricted to a single size
-    if (getMinChannelCount() == getMaxChannelCount()) {
-      return true;
-    }
-    // When the scaling threshold are not set
-    if (getMinRpcsPerChannel() == 0 && getMaxRpcsPerChannel() == Integer.MAX_VALUE) {
-      return true;
-    }
-
-    return false;
-  }
-
-  public abstract Builder toBuilder();
-
-  public static ChannelPoolSettings staticallySized(int size) {
-    return builder()
-        .setInitialChannelCount(size)
-        .setMinRpcsPerChannel(0)
-        .setMaxRpcsPerChannel(Integer.MAX_VALUE)
-        .setMinChannelCount(size)
-        .setMaxChannelCount(size)
-        .build();
-  }
-
-  public static Builder builder() {
-    return new AutoValue_ChannelPoolSettings.Builder()
-        .setInitialChannelCount(1)
-        .setMinChannelCount(1)
-        .setMaxChannelCount(200)
-        .setMinRpcsPerChannel(0)
-        .setMaxRpcsPerChannel(Integer.MAX_VALUE)
-        .setPreemptiveRefreshEnabled(false);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setMinRpcsPerChannel(int count);
-
-    public abstract Builder setMaxRpcsPerChannel(int count);
-
-    public abstract Builder setMinChannelCount(int count);
-
-    public abstract Builder setMaxChannelCount(int count);
-
-    public abstract Builder setInitialChannelCount(int count);
-
-    public abstract Builder setPreemptiveRefreshEnabled(boolean enabled);
-
-    abstract ChannelPoolSettings autoBuild();
-
-    public ChannelPoolSettings build() {
-      ChannelPoolSettings s = autoBuild();
-
-      Preconditions.checkState(
-          s.getMinRpcsPerChannel() <= s.getMaxRpcsPerChannel(), "rpcsPerChannel range is invalid");
-      Preconditions.checkState(
-          s.getMinChannelCount() > 0, "Minimum channel count must be at least 1");
-      Preconditions.checkState(
-          s.getMinChannelCount() <= s.getMaxRpcsPerChannel(), "absolute channel range is invalid");
-      Preconditions.checkState(
-          s.getMinChannelCount() <= s.getInitialChannelCount(),
-          "initial channel count be at least minChannelCount");
-      Preconditions.checkState(
-          s.getInitialChannelCount() <= s.getMaxChannelCount(),
-          "initial channel count must be less than maxChannelCount");
-      Preconditions.checkState(
-          s.getInitialChannelCount() > 0, "Initial channel count must be greater than 0");
-      return s;
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPrimer.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPrimer.java
deleted file mode 100644
index 5964de957..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPrimer.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import io.grpc.ManagedChannel;
-
-/**
- * An interface to prepare a ManagedChannel for normal requests by priming the channel
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi("For internal use by google-cloud-java clients only")
-public interface ChannelPrimer {
-  void primeChannel(ManagedChannel managedChannel);
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ExceptionResponseObserver.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ExceptionResponseObserver.java
deleted file mode 100644
index f9357f9d5..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ExceptionResponseObserver.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StateCheckingResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import java.util.concurrent.CancellationException;
-
-/** Package-private for internal use. */
-class ExceptionResponseObserver<RequestT, ResponseT>
-    extends StateCheckingResponseObserver<ResponseT> {
-  private ResponseObserver<ResponseT> innerObserver;
-  private volatile CancellationException cancellationException;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  public ExceptionResponseObserver(
-      ResponseObserver<ResponseT> innerObserver, GrpcApiExceptionFactory exceptionFactory) {
-    this.innerObserver = innerObserver;
-    this.exceptionFactory = exceptionFactory;
-  }
-
-  @Override
-  protected void onStartImpl(final StreamController controller) {
-    innerObserver.onStart(
-        new StreamController() {
-          @Override
-          public void cancel() {
-            cancellationException = new CancellationException("User cancelled stream");
-            controller.cancel();
-          }
-
-          @Override
-          public void disableAutoInboundFlowControl() {
-            controller.disableAutoInboundFlowControl();
-          }
-
-          @Override
-          public void request(int count) {
-            controller.request(count);
-          }
-        });
-  }
-
-  @Override
-  protected void onResponseImpl(ResponseT response) {
-    innerObserver.onResponse(response);
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    if (cancellationException != null) {
-      t = cancellationException;
-    } else {
-      t = exceptionFactory.create(t);
-    }
-    innerObserver.onError(t);
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    innerObserver.onComplete();
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GaxGrpcProperties.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GaxGrpcProperties.java
deleted file mode 100644
index e36665501..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GaxGrpcProperties.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.core.GaxProperties;
-import io.grpc.Channel;
-import java.util.regex.Pattern;
-
-/** Provides properties of the GAX-GRPC library. */
-@InternalApi
-public class GaxGrpcProperties {
-  private static final String GAX_GRPC_VERSION =
-      GaxProperties.getLibraryVersion(GaxGrpcProperties.class, "version.gax_grpc");
-  private static final String GRPC_VERSION =
-      GaxProperties.getLibraryVersion(Channel.class, "version.io_grpc");
-  private static final Pattern DEFAULT_API_CLIENT_HEADER_PATTERN =
-      Pattern.compile("gl-java/.+ gapic/.* gax/.+ grpc/.+");
-
-  private GaxGrpcProperties() {}
-
-  /** Returns the current version of gRPC */
-  public static String getGrpcVersion() {
-    return GRPC_VERSION;
-  }
-
-  public static String getGrpcTokenName() {
-    return "grpc";
-  }
-
-  public static String getGaxGrpcVersion() {
-    return GAX_GRPC_VERSION;
-  }
-
-  /** Returns default api client header pattern (to facilitate testing) */
-  public static Pattern getDefaultApiClientHeaderPattern() {
-    return DEFAULT_API_CLIENT_HEADER_PATTERN;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcApiExceptionFactory.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcApiExceptionFactory.java
deleted file mode 100644
index 9c3dd0a84..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcApiExceptionFactory.java
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.ErrorDetails;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.ImmutableSet;
-import com.google.protobuf.InvalidProtocolBufferException;
-import io.grpc.Metadata;
-import io.grpc.Status;
-import io.grpc.StatusException;
-import io.grpc.StatusRuntimeException;
-import java.util.Set;
-
-/**
- * Core logic for transforming GRPC exceptions into {@link ApiException}s. This logic is shared
- * amongst all the call types.
- *
- * <p>Package-private for internal use.
- */
-class GrpcApiExceptionFactory {
-
-  @VisibleForTesting static final String ERROR_DETAIL_KEY = "grpc-status-details-bin";
-  private final ImmutableSet<Code> retryableCodes;
-
-  GrpcApiExceptionFactory(Set<Code> retryCodes) {
-    this.retryableCodes = ImmutableSet.copyOf(retryCodes);
-  }
-
-  ApiException create(Throwable throwable) {
-    if (throwable instanceof StatusException) {
-      StatusException e = (StatusException) throwable;
-      return create(throwable, e.getStatus().getCode(), e.getTrailers());
-    } else if (throwable instanceof StatusRuntimeException) {
-      StatusRuntimeException e = (StatusRuntimeException) throwable;
-      return create(throwable, e.getStatus().getCode(), e.getTrailers());
-    } else if (throwable instanceof ApiException) {
-      return (ApiException) throwable;
-    } else {
-      // Do not retry on unknown throwable, even when UNKNOWN is in retryableCodes
-      return ApiExceptionFactory.createException(
-          throwable, GrpcStatusCode.of(Status.Code.UNKNOWN), false);
-    }
-  }
-
-  private ApiException create(Throwable throwable, Status.Code statusCode, Metadata metadata) {
-    boolean canRetry = retryableCodes.contains(GrpcStatusCode.grpcCodeToStatusCode(statusCode));
-    GrpcStatusCode grpcStatusCode = GrpcStatusCode.of(statusCode);
-
-    if (metadata == null) {
-      return ApiExceptionFactory.createException(throwable, grpcStatusCode, canRetry);
-    }
-
-    byte[] bytes = metadata.get(Metadata.Key.of(ERROR_DETAIL_KEY, Metadata.BINARY_BYTE_MARSHALLER));
-    if (bytes == null) {
-      return ApiExceptionFactory.createException(throwable, grpcStatusCode, canRetry);
-    }
-
-    com.google.rpc.Status status;
-    try {
-      status = com.google.rpc.Status.parseFrom(bytes);
-    } catch (InvalidProtocolBufferException e) {
-      return ApiExceptionFactory.createException(throwable, grpcStatusCode, canRetry);
-    }
-
-    ErrorDetails.Builder errorDetailsBuilder = ErrorDetails.builder();
-    errorDetailsBuilder.setRawErrorMessages(status.getDetailsList());
-    return ApiExceptionFactory.createException(
-        throwable, grpcStatusCode, canRetry, errorDetailsBuilder.build());
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallContext.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallContext.java
deleted file mode 100644
index 5f33c3644..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallContext.java
+++ /dev/null
@@ -1,580 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.internal.ApiCallContextOptions;
-import com.google.api.gax.rpc.internal.Headers;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.api.gax.tracing.BaseApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import io.grpc.CallCredentials;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.Deadline;
-import io.grpc.Metadata;
-import io.grpc.auth.MoreCallCredentials;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * GrpcCallContext encapsulates context data used to make a grpc call.
- *
- * <p>GrpcCallContext is immutable in the sense that none of its methods modifies the
- * GrpcCallContext itself or the underlying data. Methods of the form {@code withX}, such as {@link
- * #withTransportChannel}, return copies of the object, but with one field changed. The immutability
- * and thread safety of the arguments solely depends on the arguments themselves.
- */
-@BetaApi("Reference ApiCallContext instead - this class is likely to experience breaking changes")
-public final class GrpcCallContext implements ApiCallContext {
-  static final CallOptions.Key<ApiTracer> TRACER_KEY = CallOptions.Key.create("gax.tracer");
-
-  private final Channel channel;
-  private final CallOptions callOptions;
-  @Nullable private final Duration timeout;
-  @Nullable private final Duration streamWaitTimeout;
-  @Nullable private final Duration streamIdleTimeout;
-  @Nullable private final Integer channelAffinity;
-  @Nullable private final RetrySettings retrySettings;
-  @Nullable private final ImmutableSet<StatusCode.Code> retryableCodes;
-  private final ImmutableMap<String, List<String>> extraHeaders;
-  private final ApiCallContextOptions options;
-
-  /** Returns an empty instance with a null channel and default {@link CallOptions}. */
-  public static GrpcCallContext createDefault() {
-    return new GrpcCallContext(
-        null,
-        CallOptions.DEFAULT,
-        null,
-        null,
-        null,
-        null,
-        ImmutableMap.<String, List<String>>of(),
-        ApiCallContextOptions.getDefaultOptions(),
-        null,
-        null);
-  }
-
-  /** Returns an instance with the given channel and {@link CallOptions}. */
-  public static GrpcCallContext of(Channel channel, CallOptions callOptions) {
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        null,
-        null,
-        null,
-        null,
-        ImmutableMap.<String, List<String>>of(),
-        ApiCallContextOptions.getDefaultOptions(),
-        null,
-        null);
-  }
-
-  private GrpcCallContext(
-      Channel channel,
-      CallOptions callOptions,
-      @Nullable Duration timeout,
-      @Nullable Duration streamWaitTimeout,
-      @Nullable Duration streamIdleTimeout,
-      @Nullable Integer channelAffinity,
-      ImmutableMap<String, List<String>> extraHeaders,
-      ApiCallContextOptions options,
-      @Nullable RetrySettings retrySettings,
-      @Nullable Set<StatusCode.Code> retryableCodes) {
-    this.channel = channel;
-    this.callOptions = Preconditions.checkNotNull(callOptions);
-    this.timeout = timeout;
-    this.streamWaitTimeout = streamWaitTimeout;
-    this.streamIdleTimeout = streamIdleTimeout;
-    this.channelAffinity = channelAffinity;
-    this.extraHeaders = Preconditions.checkNotNull(extraHeaders);
-    this.options = Preconditions.checkNotNull(options);
-    this.retrySettings = retrySettings;
-    this.retryableCodes = retryableCodes == null ? null : ImmutableSet.copyOf(retryableCodes);
-  }
-
-  /**
-   * Returns inputContext cast to {@link GrpcCallContext}, or an empty {@link GrpcCallContext} if
-   * inputContext is null.
-   *
-   * @param inputContext the {@link ApiCallContext} to cast if it is not null
-   */
-  @Override
-  public GrpcCallContext nullToSelf(ApiCallContext inputContext) {
-    GrpcCallContext grpcCallContext;
-    if (inputContext == null) {
-      grpcCallContext = this;
-    } else {
-      if (!(inputContext instanceof GrpcCallContext)) {
-        throw new IllegalArgumentException(
-            "context must be an instance of GrpcCallContext, but found "
-                + inputContext.getClass().getName());
-      }
-      grpcCallContext = (GrpcCallContext) inputContext;
-    }
-    return grpcCallContext;
-  }
-
-  @Override
-  public GrpcCallContext withCredentials(Credentials newCredentials) {
-    Preconditions.checkNotNull(newCredentials);
-    CallCredentials callCredentials = MoreCallCredentials.from(newCredentials);
-    return withCallOptions(callOptions.withCallCredentials(callCredentials));
-  }
-
-  @Override
-  public GrpcCallContext withTransportChannel(TransportChannel inputChannel) {
-    Preconditions.checkNotNull(inputChannel);
-    if (!(inputChannel instanceof GrpcTransportChannel)) {
-      throw new IllegalArgumentException(
-          "Expected GrpcTransportChannel, got " + inputChannel.getClass().getName());
-    }
-    GrpcTransportChannel transportChannel = (GrpcTransportChannel) inputChannel;
-    return withChannel(transportChannel.getChannel());
-  }
-
-  @Override
-  public GrpcCallContext withTimeout(@Nullable Duration timeout) {
-    // Default RetrySettings use 0 for RPC timeout. Treat that as disabled timeouts.
-    if (timeout != null && (timeout.isZero() || timeout.isNegative())) {
-      timeout = null;
-    }
-
-    // Prevent expanding timeouts
-    if (timeout != null && this.timeout != null && this.timeout.compareTo(timeout) <= 0) {
-      return this;
-    }
-
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Nullable
-  @Override
-  public Duration getTimeout() {
-    return timeout;
-  }
-
-  @Override
-  public GrpcCallContext withStreamWaitTimeout(@Nullable Duration streamWaitTimeout) {
-    if (streamWaitTimeout != null) {
-      Preconditions.checkArgument(
-          streamWaitTimeout.compareTo(Duration.ZERO) >= 0, "Invalid timeout: < 0 s");
-    }
-
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public GrpcCallContext withStreamIdleTimeout(@Nullable Duration streamIdleTimeout) {
-    if (streamIdleTimeout != null) {
-      Preconditions.checkArgument(
-          streamIdleTimeout.compareTo(Duration.ZERO) >= 0, "Invalid timeout: < 0 s");
-    }
-
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @BetaApi("The surface for channel affinity is not stable yet and may change in the future.")
-  public GrpcCallContext withChannelAffinity(@Nullable Integer affinity) {
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        affinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  @Override
-  public GrpcCallContext withExtraHeaders(Map<String, List<String>> extraHeaders) {
-    Preconditions.checkNotNull(extraHeaders);
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(this.extraHeaders, extraHeaders);
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        newExtraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public RetrySettings getRetrySettings() {
-    return retrySettings;
-  }
-
-  @Override
-  public GrpcCallContext withRetrySettings(RetrySettings retrySettings) {
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public Set<StatusCode.Code> getRetryableCodes() {
-    return retryableCodes;
-  }
-
-  @Override
-  public GrpcCallContext withRetryableCodes(Set<StatusCode.Code> retryableCodes) {
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public ApiCallContext merge(ApiCallContext inputCallContext) {
-    if (inputCallContext == null) {
-      return this;
-    }
-    if (!(inputCallContext instanceof GrpcCallContext)) {
-      throw new IllegalArgumentException(
-          "context must be an instance of GrpcCallContext, but found "
-              + inputCallContext.getClass().getName());
-    }
-    GrpcCallContext grpcCallContext = (GrpcCallContext) inputCallContext;
-
-    Channel newChannel = grpcCallContext.channel;
-    if (newChannel == null) {
-      newChannel = channel;
-    }
-
-    Deadline newDeadline = grpcCallContext.callOptions.getDeadline();
-    if (newDeadline == null) {
-      newDeadline = callOptions.getDeadline();
-    }
-
-    CallCredentials newCallCredentials = grpcCallContext.callOptions.getCredentials();
-    if (newCallCredentials == null) {
-      newCallCredentials = callOptions.getCredentials();
-    }
-
-    ApiTracer newTracer = grpcCallContext.callOptions.getOption(TRACER_KEY);
-    if (newTracer == null) {
-      newTracer = callOptions.getOption(TRACER_KEY);
-    }
-
-    Duration newTimeout = grpcCallContext.timeout;
-    if (newTimeout == null) {
-      newTimeout = timeout;
-    }
-
-    Duration newStreamWaitTimeout = grpcCallContext.streamWaitTimeout;
-    if (newStreamWaitTimeout == null) {
-      newStreamWaitTimeout = streamWaitTimeout;
-    }
-
-    Duration newStreamIdleTimeout = grpcCallContext.streamIdleTimeout;
-    if (newStreamIdleTimeout == null) {
-      newStreamIdleTimeout = streamIdleTimeout;
-    }
-
-    Integer newChannelAffinity = grpcCallContext.channelAffinity;
-    if (newChannelAffinity == null) {
-      newChannelAffinity = channelAffinity;
-    }
-
-    RetrySettings newRetrySettings = grpcCallContext.retrySettings;
-    if (newRetrySettings == null) {
-      newRetrySettings = retrySettings;
-    }
-
-    Set<StatusCode.Code> newRetryableCodes = grpcCallContext.retryableCodes;
-    if (newRetryableCodes == null) {
-      newRetryableCodes = retryableCodes;
-    }
-
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(extraHeaders, grpcCallContext.extraHeaders);
-
-    ApiCallContextOptions newOptions = options.merge(grpcCallContext.options);
-
-    CallOptions newCallOptions =
-        grpcCallContext
-            .callOptions
-            .withCallCredentials(newCallCredentials)
-            .withDeadline(newDeadline);
-
-    if (newTracer != null) {
-      newCallOptions = newCallOptions.withOption(TRACER_KEY, newTracer);
-    }
-
-    return new GrpcCallContext(
-        newChannel,
-        newCallOptions,
-        newTimeout,
-        newStreamWaitTimeout,
-        newStreamIdleTimeout,
-        newChannelAffinity,
-        newExtraHeaders,
-        newOptions,
-        newRetrySettings,
-        newRetryableCodes);
-  }
-
-  /** The {@link Channel} set on this context. */
-  public Channel getChannel() {
-    return channel;
-  }
-
-  /** The {@link CallOptions} set on this context. */
-  public CallOptions getCallOptions() {
-    return callOptions;
-  }
-
-  /**
-   * The stream wait timeout set for this context.
-   *
-   * @see ApiCallContext#withStreamWaitTimeout(Duration)
-   */
-  @Override
-  @Nullable
-  public Duration getStreamWaitTimeout() {
-    return streamWaitTimeout;
-  }
-
-  /**
-   * The stream idle timeout set for this context.
-   *
-   * @see ApiCallContext#withStreamIdleTimeout(Duration)
-   */
-  @Override
-  @Nullable
-  public Duration getStreamIdleTimeout() {
-    return streamIdleTimeout;
-  }
-
-  /** The channel affinity for this context. */
-  @Nullable
-  public Integer getChannelAffinity() {
-    return channelAffinity;
-  }
-
-  /** The extra header for this context. */
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  @Override
-  public Map<String, List<String>> getExtraHeaders() {
-    return extraHeaders;
-  }
-
-  /** Returns a new instance with the channel set to the given channel. */
-  public GrpcCallContext withChannel(Channel newChannel) {
-    return new GrpcCallContext(
-        newChannel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  /** Returns a new instance with the call options set to the given call options. */
-  public GrpcCallContext withCallOptions(CallOptions newCallOptions) {
-    return new GrpcCallContext(
-        channel,
-        newCallOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  public GrpcCallContext withRequestParamsDynamicHeaderOption(String requestParams) {
-    CallOptions newCallOptions =
-        CallOptionsUtil.putRequestParamsDynamicHeaderOption(callOptions, requestParams);
-
-    return withCallOptions(newCallOptions);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  @Nonnull
-  public ApiTracer getTracer() {
-    ApiTracer tracer = callOptions.getOption(TRACER_KEY);
-    if (tracer == null) {
-      tracer = BaseApiTracer.getInstance();
-    }
-    return tracer;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public GrpcCallContext withTracer(@Nonnull ApiTracer tracer) {
-    Preconditions.checkNotNull(tracer);
-    return withCallOptions(callOptions.withOption(TRACER_KEY, tracer));
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public <T> GrpcCallContext withOption(Key<T> key, T value) {
-    ApiCallContextOptions newOptions = options.withOption(key, value);
-    return new GrpcCallContext(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        newOptions,
-        retrySettings,
-        retryableCodes);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public <T> T getOption(Key<T> key) {
-    return options.getOption(key);
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(
-        channel,
-        callOptions,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        channelAffinity,
-        extraHeaders,
-        options,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-
-    GrpcCallContext that = (GrpcCallContext) o;
-    return Objects.equals(channel, that.channel)
-        && Objects.equals(callOptions, that.callOptions)
-        && Objects.equals(timeout, that.timeout)
-        && Objects.equals(streamWaitTimeout, that.streamWaitTimeout)
-        && Objects.equals(streamIdleTimeout, that.streamIdleTimeout)
-        && Objects.equals(channelAffinity, that.channelAffinity)
-        && Objects.equals(extraHeaders, that.extraHeaders)
-        && Objects.equals(options, that.options)
-        && Objects.equals(retrySettings, that.retrySettings)
-        && Objects.equals(retryableCodes, that.retryableCodes);
-  }
-
-  Metadata getMetadata() {
-    Metadata metadata = new Metadata();
-    for (Map.Entry<String, List<String>> header : extraHeaders.entrySet()) {
-      String headerKey = header.getKey();
-      for (String headerValue : header.getValue()) {
-        metadata.put(Metadata.Key.of(headerKey, Metadata.ASCII_STRING_MARSHALLER), headerValue);
-      }
-    }
-    return metadata;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallSettings.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallSettings.java
deleted file mode 100644
index a5aef3d69..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallSettings.java
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import io.grpc.MethodDescriptor;
-
-/** Grpc-specific settings for creating callables. */
-public class GrpcCallSettings<RequestT, ResponseT> {
-  private final MethodDescriptor<RequestT, ResponseT> methodDescriptor;
-  private final RequestParamsExtractor<RequestT> paramsExtractor;
-  private final boolean alwaysAwaitTrailers;
-
-  private GrpcCallSettings(Builder<RequestT, ResponseT> builder) {
-    this.methodDescriptor = builder.methodDescriptor;
-    this.paramsExtractor = builder.paramsExtractor;
-    this.alwaysAwaitTrailers = builder.shouldAwaitTrailers;
-  }
-
-  public MethodDescriptor<RequestT, ResponseT> getMethodDescriptor() {
-    return methodDescriptor;
-  }
-
-  public RequestParamsExtractor<RequestT> getParamsExtractor() {
-    return paramsExtractor;
-  }
-
-  @BetaApi
-  public boolean shouldAwaitTrailers() {
-    return alwaysAwaitTrailers;
-  }
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new Builder<RequestT, ResponseT>().setShouldAwaitTrailers(true);
-  }
-
-  public static <RequestT, ResponseT> GrpcCallSettings<RequestT, ResponseT> create(
-      MethodDescriptor<RequestT, ResponseT> methodDescriptor) {
-    return GrpcCallSettings.<RequestT, ResponseT>newBuilder()
-        .setMethodDescriptor(methodDescriptor)
-        .build();
-  }
-
-  public Builder toBuilder() {
-    return new Builder<>(this);
-  }
-
-  public static class Builder<RequestT, ResponseT> {
-    private MethodDescriptor<RequestT, ResponseT> methodDescriptor;
-    private RequestParamsExtractor<RequestT> paramsExtractor;
-    private boolean shouldAwaitTrailers;
-
-    private Builder() {}
-
-    private Builder(GrpcCallSettings<RequestT, ResponseT> settings) {
-      this.methodDescriptor = settings.methodDescriptor;
-      this.paramsExtractor = settings.paramsExtractor;
-      this.shouldAwaitTrailers = settings.alwaysAwaitTrailers;
-    }
-
-    public Builder<RequestT, ResponseT> setMethodDescriptor(
-        MethodDescriptor<RequestT, ResponseT> methodDescriptor) {
-      this.methodDescriptor = methodDescriptor;
-      return this;
-    }
-
-    public Builder<RequestT, ResponseT> setParamsExtractor(
-        RequestParamsExtractor<RequestT> paramsExtractor) {
-      this.paramsExtractor = paramsExtractor;
-      return this;
-    }
-
-    @BetaApi
-    public Builder<RequestT, ResponseT> setShouldAwaitTrailers(boolean b) {
-      this.shouldAwaitTrailers = b;
-      return this;
-    }
-
-    public GrpcCallSettings<RequestT, ResponseT> build() {
-      return new GrpcCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallableFactory.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallableFactory.java
deleted file mode 100644
index 8a0c4e0b3..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallableFactory.java
+++ /dev/null
@@ -1,332 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.Callables;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.tracing.SpanName;
-import com.google.api.gax.tracing.TracedBatchingCallable;
-import com.google.api.gax.tracing.TracedBidiCallable;
-import com.google.api.gax.tracing.TracedClientStreamingCallable;
-import com.google.api.gax.tracing.TracedOperationCallable;
-import com.google.api.gax.tracing.TracedOperationInitialCallable;
-import com.google.api.gax.tracing.TracedServerStreamingCallable;
-import com.google.api.gax.tracing.TracedUnaryCallable;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableSet;
-import com.google.longrunning.Operation;
-import com.google.longrunning.stub.OperationsStub;
-import io.grpc.MethodDescriptor;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-import javax.annotation.Nonnull;
-
-/** Class with utility methods to create grpc-based direct callables. */
-public class GrpcCallableFactory {
-  // Used to extract service and method name from a grpc MethodDescriptor.
-  private static final Pattern FULL_METHOD_NAME_REGEX = Pattern.compile("^.*?([^./]+)/([^./]+)$");
-
-  private GrpcCallableFactory() {}
-
-  /**
-   * Create a Unary callable object with minimal grpc-specific functionality.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param callSettings the Unary call settings
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBaseUnaryCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      UnaryCallSettings<?, ?> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        GrpcRawCallableFactory.createUnaryCallable(
-            grpcCallSettings, callSettings.getRetryableCodes());
-
-    callable = Callables.retrying(callable, callSettings, clientContext);
-
-    return callable;
-  }
-
-  /**
-   * Create a callable object with grpc-specific functionality. Designed for use by generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        createBaseUnaryCallable(grpcCallSettings, callSettings, clientContext);
-
-    callable =
-        new TracedUnaryCallable<>(
-            callable,
-            clientContext.getTracerFactory(),
-            getSpanName(grpcCallSettings.getMethodDescriptor()));
-
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> innerCallable =
-        createBaseUnaryCallable(grpcCallSettings, pagedCallSettings, clientContext);
-    UnaryCallable<RequestT, PagedListResponseT> pagedCallable =
-        Callables.paged(innerCallable, pagedCallSettings);
-    return pagedCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> baseCallable =
-        createBaseUnaryCallable(grpcCallSettings, batchingCallSettings, clientContext);
-
-    // NOTE: Since batching happens asynchronously and the outermost callable simply buffers the
-    // request. Tracing will only start on the inner callable that accepts the batch.
-    UnaryCallable<RequestT, ResponseT> tracedCallable =
-        new TracedBatchingCallable<>(
-            baseCallable,
-            clientContext.getTracerFactory(),
-            getSpanName(grpcCallSettings.getMethodDescriptor()),
-            batchingCallSettings.getBatchingDescriptor());
-
-    UnaryCallable<RequestT, ResponseT> batchingCallable =
-        Callables.batching(tracedCallable, batchingCallSettings, clientContext);
-    return batchingCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Creates a callable object that represents a long-running operation. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param operationCallSettings {@link OperationCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @param operationsStub {@link OperationsStub} to use to poll for updates on the Operation.
-   * @return {@link com.google.api.gax.rpc.OperationCallable} callable object.
-   */
-  public static <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          GrpcCallSettings<RequestT, Operation> grpcCallSettings,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          OperationsStub operationsStub) {
-
-    SpanName initialSpanName = getSpanName(grpcCallSettings.getMethodDescriptor());
-    SpanName operationSpanName =
-        SpanName.of(initialSpanName.getClientName(), initialSpanName.getMethodName() + "Operation");
-
-    UnaryCallable<RequestT, Operation> initialGrpcCallable =
-        createBaseUnaryCallable(
-            grpcCallSettings, operationCallSettings.getInitialCallSettings(), clientContext);
-    UnaryCallable<RequestT, OperationSnapshot> initialCallable =
-        new GrpcOperationSnapshotCallable<>(initialGrpcCallable);
-
-    // Create a sub-trace for the initial RPC that starts the operation.
-    UnaryCallable<RequestT, OperationSnapshot> tracedInitialCallable =
-        new TracedOperationInitialCallable<>(
-            initialCallable, clientContext.getTracerFactory(), initialSpanName);
-
-    LongRunningClient longRunningClient = new GrpcLongRunningClient(operationsStub);
-    OperationCallable<RequestT, ResponseT, MetadataT> operationCallable =
-        Callables.longRunningOperation(
-            tracedInitialCallable, operationCallSettings, clientContext, longRunningClient);
-
-    OperationCallable<RequestT, ResponseT, MetadataT> tracedOperationCallable =
-        new TracedOperationCallable<>(
-            operationCallable, clientContext.getTracerFactory(), operationSpanName);
-
-    return tracedOperationCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a bidirectional streaming callable object with grpc-specific functionality. Designed for
-   * use by generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link BidiStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    BidiStreamingCallable<RequestT, ResponseT> callable =
-        GrpcRawCallableFactory.createBidiStreamingCallable(
-            grpcCallSettings, ImmutableSet.<StatusCode.Code>of());
-
-    callable =
-        new TracedBidiCallable<>(
-            callable,
-            clientContext.getTracerFactory(),
-            getSpanName(grpcCallSettings.getMethodDescriptor()));
-
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a server-streaming callable with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @deprecated Please use ServerStreamingCallSettings
-   */
-  @Deprecated
-  public static <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-
-    // up convert to new settings
-    ServerStreamingCallSettings<RequestT, ResponseT> serverStreamingCallSettings =
-        ServerStreamingCallSettings.<RequestT, ResponseT>newBuilder().build();
-
-    return createServerStreamingCallable(
-        grpcCallSettings, serverStreamingCallSettings, clientContext);
-  }
-
-  /**
-   * Create a server-streaming callable with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   */
-  public static <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          ServerStreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    ServerStreamingCallable<RequestT, ResponseT> callable =
-        GrpcRawCallableFactory.createServerStreamingCallable(
-            grpcCallSettings, streamingCallSettings.getRetryableCodes());
-
-    if (clientContext.getStreamWatchdog() != null) {
-      callable = Callables.watched(callable, streamingCallSettings, clientContext);
-    }
-
-    callable = Callables.retrying(callable, streamingCallSettings, clientContext);
-
-    callable =
-        new TracedServerStreamingCallable<>(
-            callable,
-            clientContext.getTracerFactory(),
-            getSpanName(grpcCallSettings.getMethodDescriptor()));
-
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a client-streaming callable object with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link ClientStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    ClientStreamingCallable<RequestT, ResponseT> callable =
-        GrpcRawCallableFactory.createClientStreamingCallable(
-            grpcCallSettings, ImmutableSet.<StatusCode.Code>of());
-
-    callable =
-        new TracedClientStreamingCallable<>(
-            callable,
-            clientContext.getTracerFactory(),
-            getSpanName(grpcCallSettings.getMethodDescriptor()));
-
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  @InternalApi("Visible for testing")
-  static SpanName getSpanName(@Nonnull MethodDescriptor<?, ?> methodDescriptor) {
-    Matcher matcher = FULL_METHOD_NAME_REGEX.matcher(methodDescriptor.getFullMethodName());
-
-    Preconditions.checkArgument(matcher.matches(), "Invalid fullMethodName");
-    return SpanName.of(matcher.group(1), matcher.group(2));
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcChannelUUIDInterceptor.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcChannelUUIDInterceptor.java
deleted file mode 100644
index ac450689e..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcChannelUUIDInterceptor.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.tracing.ApiTracer;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.MethodDescriptor;
-import java.util.UUID;
-
-class GrpcChannelUUIDInterceptor implements ClientInterceptor {
-  private final String uuid = UUID.randomUUID().toString();
-
-  @Override
-  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
-      MethodDescriptor<ReqT, RespT> methodDescriptor, CallOptions callOptions, Channel channel) {
-
-    ApiTracer apiTracer = callOptions.getOption(GrpcCallContext.TRACER_KEY);
-    if (apiTracer != null) {
-      apiTracer.connectionSelected(uuid);
-    }
-
-    return channel.newCall(methodDescriptor, callOptions);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcClientCalls.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcClientCalls.java
deleted file mode 100644
index bc72f6f1f..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcClientCalls.java
+++ /dev/null
@@ -1,199 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.client.util.Preconditions;
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.BetaApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.tracing.ApiTracer.Scope;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.ClientInterceptors;
-import io.grpc.Deadline;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-import io.grpc.stub.MetadataUtils;
-import java.util.concurrent.TimeUnit;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-/**
- * {@code GrpcClientCalls} creates a new {@code ClientCall} from the given call context.
- *
- * <p>Package-private for internal use.
- */
-class GrpcClientCalls {
-  private static final Logger LOGGER = Logger.getLogger(GrpcDirectCallable.class.getName());
-
-  private GrpcClientCalls() {};
-
-  public static <RequestT, ResponseT> ClientCall<RequestT, ResponseT> newCall(
-      MethodDescriptor<RequestT, ResponseT> descriptor, ApiCallContext context) {
-    if (!(context instanceof GrpcCallContext)) {
-      throw new IllegalArgumentException(
-          "context must be an instance of GrpcCallContext, but found "
-              + context.getClass().getName());
-    }
-
-    GrpcCallContext grpcContext = (GrpcCallContext) context;
-    Preconditions.checkNotNull(grpcContext.getChannel());
-
-    CallOptions callOptions = grpcContext.getCallOptions();
-    Preconditions.checkNotNull(callOptions);
-
-    // Try to convert the timeout into a deadline and use it if it occurs before the actual deadline
-    if (grpcContext.getTimeout() != null) {
-      Deadline newDeadline =
-          Deadline.after(grpcContext.getTimeout().toMillis(), TimeUnit.MILLISECONDS);
-      Deadline oldDeadline = callOptions.getDeadline();
-
-      if (oldDeadline == null || newDeadline.isBefore(oldDeadline)) {
-        callOptions = callOptions.withDeadline(newDeadline);
-      }
-    }
-
-    Channel channel = grpcContext.getChannel();
-    if (grpcContext.getChannelAffinity() != null && channel instanceof ChannelPool) {
-      channel = ((ChannelPool) channel).getChannel(grpcContext.getChannelAffinity());
-    }
-
-    if (!grpcContext.getExtraHeaders().isEmpty()) {
-      ClientInterceptor interceptor =
-          MetadataUtils.newAttachHeadersInterceptor(grpcContext.getMetadata());
-      channel = ClientInterceptors.intercept(channel, interceptor);
-    }
-
-    try (Scope ignored = grpcContext.getTracer().inScope()) {
-      return channel.newCall(descriptor, callOptions);
-    }
-  }
-
-  /**
-   * A work-alike of {@link io.grpc.stub.ClientCalls#futureUnaryCall(ClientCall, Object)}.
-   *
-   * <p>The only difference is that unlike grpc-stub's implementation. This implementation doesn't
-   * wait for trailers to resolve a unary RPC. This can save milliseconds when the server is
-   * overloaded.
-   */
-  @BetaApi
-  static <RequestT, ResponseT> ApiFuture<ResponseT> eagerFutureUnaryCall(
-      ClientCall<RequestT, ResponseT> clientCall, RequestT request) {
-    // Start the call
-    GrpcFuture<ResponseT> future = new GrpcFuture<>(clientCall);
-    clientCall.start(new EagerFutureListener<>(future), new Metadata());
-
-    // Send the request
-    try {
-      clientCall.sendMessage(request);
-      clientCall.halfClose();
-      // Request an extra message to detect misconfigured servers
-      clientCall.request(2);
-    } catch (Throwable sendError) {
-      // Cancel if anything goes wrong
-      try {
-        clientCall.cancel(null, sendError);
-      } catch (Throwable cancelError) {
-        LOGGER.log(Level.SEVERE, "Error encountered while closing it", sendError);
-      }
-
-      throw sendError;
-    }
-
-    return future;
-  }
-
-  /** Thin wrapper around an ApiFuture that will cancel the underlying ClientCall. */
-  private static class GrpcFuture<T> extends AbstractApiFuture<T> {
-    private final ClientCall<?, T> call;
-
-    private GrpcFuture(ClientCall<?, T> call) {
-      this.call = call;
-    }
-
-    @Override
-    protected void interruptTask() {
-      call.cancel("GrpcFuture was cancelled", null);
-    }
-
-    @Override
-    public boolean set(T value) {
-      return super.set(value);
-    }
-
-    @Override
-    public boolean setException(Throwable throwable) {
-      return super.setException(throwable);
-    }
-  }
-
-  /**
-   * A bridge between gRPC's ClientCall.Listener to an ApiFuture.
-   *
-   * <p>The Listener will eagerly resolve the future when the first message is received and will not
-   * wait for the trailers. This should cut down on the latency at the expense of safety. If the
-   * server is misconfigured and sends a second response for a unary call, the error will be logged,
-   * but the future will still be successful.
-   */
-  private static class EagerFutureListener<T> extends ClientCall.Listener<T> {
-    private final GrpcFuture<T> future;
-
-    private EagerFutureListener(GrpcFuture<T> future) {
-      this.future = future;
-    }
-
-    @Override
-    public void onMessage(T message) {
-      if (!future.set(message)) {
-        throw Status.INTERNAL
-            .withDescription("More than one value received for unary call")
-            .asRuntimeException();
-      }
-    }
-
-    @Override
-    public void onClose(Status status, Metadata trailers) {
-      if (!future.isDone()) {
-        future.setException(
-            Status.INTERNAL
-                .withDescription("No value received for unary call")
-                .asException(trailers));
-      }
-      if (!status.isOk()) {
-        LOGGER.log(
-            Level.WARNING, "Received error for unary call after receiving a successful response");
-      }
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectBidiStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectBidiStreamingCallable.java
deleted file mode 100644
index 178044dc9..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectBidiStreamingCallable.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamReadyObserver;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.common.base.Preconditions;
-import io.grpc.ClientCall;
-import io.grpc.MethodDescriptor;
-
-/**
- * {@code GrpcDirectBidiStreamingCallable} creates bidirectional streaming gRPC calls.
- *
- * <p>It is used to bridge the abstractions provided by gRPC and GAX.
- *
- * <p>Package-private for internal use.
- */
-class GrpcDirectBidiStreamingCallable<RequestT, ResponseT>
-    extends BidiStreamingCallable<RequestT, ResponseT> {
-  private final MethodDescriptor<RequestT, ResponseT> descriptor;
-
-  GrpcDirectBidiStreamingCallable(MethodDescriptor<RequestT, ResponseT> descriptor) {
-    this.descriptor = Preconditions.checkNotNull(descriptor);
-  }
-
-  @Override
-  public ClientStream<RequestT> internalCall(
-      ResponseObserver<ResponseT> responseObserver,
-      final ClientStreamReadyObserver<RequestT> onReady,
-      ApiCallContext context) {
-    Preconditions.checkNotNull(responseObserver);
-    final ClientCall<RequestT, ResponseT> call = GrpcClientCalls.newCall(descriptor, context);
-    final ClientStream<RequestT> clientStream =
-        new ClientStream<RequestT>() {
-          @Override
-          public void send(RequestT request) {
-            call.sendMessage(request);
-          }
-
-          @Override
-          public void closeSendWithError(Throwable t) {
-            call.cancel(null, t);
-          }
-
-          @Override
-          public void closeSend() {
-            call.halfClose();
-          }
-
-          @Override
-          public boolean isSendReady() {
-            return call.isReady();
-          }
-        };
-
-    GrpcDirectStreamController<RequestT, ResponseT> controller =
-        new GrpcDirectStreamController<>(
-            call,
-            responseObserver,
-            new Runnable() {
-              @Override
-              public void run() {
-                onReady.onReady(clientStream);
-              }
-            });
-    controller.startBidi();
-
-    return clientStream;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectCallable.java
deleted file mode 100644
index 5b6a5f1ba..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectCallable.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ListenableFutureToApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-import io.grpc.ClientCall;
-import io.grpc.MethodDescriptor;
-import io.grpc.stub.ClientCalls;
-
-/**
- * {@code GrpcDirectCallable} creates gRPC calls.
- *
- * <p>Package-private for internal use.
- */
-class GrpcDirectCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final MethodDescriptor<RequestT, ResponseT> descriptor;
-  private final boolean awaitTrailers;
-
-  GrpcDirectCallable(MethodDescriptor<RequestT, ResponseT> descriptor, boolean awaitTrailers) {
-    this.descriptor = Preconditions.checkNotNull(descriptor);
-    this.awaitTrailers = awaitTrailers;
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    Preconditions.checkNotNull(request);
-    Preconditions.checkNotNull(inputContext);
-
-    ClientCall<RequestT, ResponseT> clientCall = GrpcClientCalls.newCall(descriptor, inputContext);
-
-    if (awaitTrailers) {
-      return new ListenableFutureToApiFuture<>(ClientCalls.futureUnaryCall(clientCall, request));
-    } else {
-      return GrpcClientCalls.eagerFutureUnaryCall(clientCall, request);
-    }
-  }
-
-  @Override
-  public String toString() {
-    return String.format("direct(%s)", descriptor);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectClientStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectClientStreamingCallable.java
deleted file mode 100644
index 93c1a9562..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectClientStreamingCallable.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.common.base.Preconditions;
-import io.grpc.ClientCall;
-import io.grpc.MethodDescriptor;
-import io.grpc.stub.ClientCalls;
-
-/**
- * {@code GrpcDirectClientStreamingCallable} creates client-streaming gRPC calls.
- *
- * <p>It is used to bridge the abstractions provided by gRPC and GAX.
- *
- * <p>Package-private for internal use.
- */
-class GrpcDirectClientStreamingCallable<RequestT, ResponseT>
-    extends ClientStreamingCallable<RequestT, ResponseT> {
-  private final MethodDescriptor<RequestT, ResponseT> descriptor;
-
-  GrpcDirectClientStreamingCallable(MethodDescriptor<RequestT, ResponseT> descriptor) {
-    this.descriptor = Preconditions.checkNotNull(descriptor);
-  }
-
-  @Override
-  public ApiStreamObserver<RequestT> clientStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context) {
-    Preconditions.checkNotNull(responseObserver);
-    ClientCall<RequestT, ResponseT> call = GrpcClientCalls.newCall(descriptor, context);
-    return new StreamObserverDelegate<>(
-        ClientCalls.asyncClientStreamingCall(
-            call, new ApiStreamObserverDelegate<>(responseObserver)));
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallable.java
deleted file mode 100644
index 2b562f07a..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallable.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-import io.grpc.ClientCall;
-import io.grpc.MethodDescriptor;
-
-/**
- * {@code GrpcDirectServerStreamingCallable} creates server-streaming gRPC calls.
- *
- * <p>In a chain of {@link ServerStreamingCallable}s this is the innermost callable. It wraps a
- * {@link ClientCall} in a {@link StreamController} and the downstream {@link ResponseObserver} in a
- * {@link ClientCall.Listener}. This forms a bidirectional bridge between gax & grpc. This is
- * implemented on top of {@link ClientCall.Listener} because {@link
- * io.grpc.stub.ClientResponseObserver} is currently marked as {@link io.grpc.ExperimentalApi}.
- *
- * <p>Package-private for internal use.
- */
-class GrpcDirectServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-  private final MethodDescriptor<RequestT, ResponseT> descriptor;
-
-  GrpcDirectServerStreamingCallable(MethodDescriptor<RequestT, ResponseT> descriptor) {
-    this.descriptor = Preconditions.checkNotNull(descriptor);
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-    Preconditions.checkNotNull(request);
-    Preconditions.checkNotNull(responseObserver);
-
-    ClientCall<RequestT, ResponseT> call = GrpcClientCalls.newCall(descriptor, context);
-    GrpcDirectStreamController<RequestT, ResponseT> controller =
-        new GrpcDirectStreamController<>(call, responseObserver);
-    controller.start(request);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectStreamController.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectStreamController.java
deleted file mode 100644
index e7b52b808..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcDirectStreamController.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-import io.grpc.ClientCall;
-import io.grpc.Metadata;
-import io.grpc.Status;
-import java.util.concurrent.CancellationException;
-
-/**
- * Wraps a GRPC ClientCall in a {@link StreamController}. It feeds events to a {@link
- * ResponseObserver} and allows for back pressure.
- *
- * <p>Package-private for internal use.
- */
-class GrpcDirectStreamController<RequestT, ResponseT> implements StreamController {
-  private static final Runnable NOOP_RUNNABLE =
-      new Runnable() {
-        @Override
-        public void run() {}
-      };
-
-  private final ClientCall<RequestT, ResponseT> clientCall;
-  private final ResponseObserver<ResponseT> responseObserver;
-  private final Runnable onReady;
-  private boolean hasStarted;
-  private boolean autoflowControl = true;
-  private int numRequested;
-  private volatile CancellationException cancellationException;
-
-  GrpcDirectStreamController(
-      ClientCall<RequestT, ResponseT> clientCall, ResponseObserver<ResponseT> responseObserver) {
-    this(clientCall, responseObserver, NOOP_RUNNABLE);
-  }
-
-  GrpcDirectStreamController(
-      ClientCall<RequestT, ResponseT> clientCall,
-      ResponseObserver<ResponseT> responseObserver,
-      Runnable onReady) {
-    this.clientCall = clientCall;
-    this.responseObserver = responseObserver;
-    this.onReady = onReady;
-  }
-
-  @Override
-  public void cancel() {
-    cancellationException = new CancellationException("User cancelled stream");
-    clientCall.cancel(null, cancellationException);
-  }
-
-  @Override
-  public void disableAutoInboundFlowControl() {
-    Preconditions.checkState(
-        !hasStarted, "Can't disable automatic flow control after the stream has started.");
-    autoflowControl = false;
-  }
-
-  @Override
-  public void request(int count) {
-    Preconditions.checkState(!autoflowControl, "Autoflow control is enabled.");
-
-    // Buffer the requested count in case the consumer requested responses in the onStart()
-    if (!hasStarted) {
-      numRequested += count;
-    } else {
-      clientCall.request(count);
-    }
-  }
-
-  void start(RequestT request) {
-    startCommon();
-    clientCall.sendMessage(request);
-    clientCall.halfClose();
-  }
-
-  void startBidi() {
-    startCommon();
-  }
-
-  private void startCommon() {
-    responseObserver.onStart(this);
-
-    this.hasStarted = true;
-
-    clientCall.start(new ResponseObserverAdapter(), new Metadata());
-
-    if (autoflowControl) {
-      clientCall.request(1);
-    } else if (numRequested > 0) {
-      clientCall.request(numRequested);
-    }
-  }
-
-  private class ResponseObserverAdapter extends ClientCall.Listener<ResponseT> {
-    /**
-     * Notifies the outerObserver of the new message and if automatic flow control is enabled,
-     * requests the next message. Any errors raised by the outerObserver will be bubbled up to GRPC,
-     * which cancel the ClientCall and close this listener.
-     *
-     * @param message The new message.
-     */
-    @Override
-    public void onMessage(ResponseT message) {
-      responseObserver.onResponse(message);
-
-      if (autoflowControl) {
-        clientCall.request(1);
-      }
-    }
-
-    @Override
-    public void onClose(Status status, Metadata trailers) {
-      if (status.isOk()) {
-        responseObserver.onComplete();
-      } else if (cancellationException != null) {
-        // Intercept cancellations and replace with the top level cause
-        responseObserver.onError(cancellationException);
-      } else {
-        responseObserver.onError(status.asRuntimeException(trailers));
-      }
-    }
-
-    @Override
-    public void onReady() {
-      onReady.run();
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionBidiStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionBidiStreamingCallable.java
deleted file mode 100644
index b6a9ee024..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionBidiStreamingCallable.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamReadyObserver;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StatusCode;
-import java.util.Set;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-final class GrpcExceptionBidiStreamingCallable<RequestT, ResponseT>
-    extends BidiStreamingCallable<RequestT, ResponseT> {
-  private final BidiStreamingCallable<RequestT, ResponseT> innerCallable;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  GrpcExceptionBidiStreamingCallable(
-      BidiStreamingCallable<RequestT, ResponseT> innerCallable,
-      Set<StatusCode.Code> retryableCodes) {
-    this.innerCallable = innerCallable;
-    this.exceptionFactory = new GrpcApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public ClientStream<RequestT> internalCall(
-      final ResponseObserver<ResponseT> responseObserver,
-      ClientStreamReadyObserver<RequestT> onReady,
-      ApiCallContext context) {
-    return innerCallable.internalCall(
-        new ExceptionResponseObserver<>(responseObserver, exceptionFactory), onReady, context);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionCallable.java
deleted file mode 100644
index b069294d0..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionCallable.java
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-import java.util.Set;
-import java.util.concurrent.CancellationException;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-class GrpcExceptionCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  GrpcExceptionCallable(
-      UnaryCallable<RequestT, ResponseT> callable, Set<StatusCode.Code> retryableCodes) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.exceptionFactory = new GrpcApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    GrpcCallContext context = GrpcCallContext.createDefault().nullToSelf(inputContext);
-    ApiFuture<ResponseT> innerCallFuture = callable.futureCall(request, context);
-    ExceptionTransformingFuture transformingFuture =
-        new ExceptionTransformingFuture(innerCallFuture);
-    ApiFutures.addCallback(innerCallFuture, transformingFuture, directExecutor());
-    return transformingFuture;
-  }
-
-  private class ExceptionTransformingFuture extends AbstractApiFuture<ResponseT>
-      implements ApiFutureCallback<ResponseT> {
-    private ApiFuture<ResponseT> innerCallFuture;
-    private volatile boolean cancelled = false;
-
-    public ExceptionTransformingFuture(ApiFuture<ResponseT> innerCallFuture) {
-      this.innerCallFuture = innerCallFuture;
-    }
-
-    @Override
-    protected void interruptTask() {
-      cancelled = true;
-      innerCallFuture.cancel(true);
-    }
-
-    @Override
-    public void onSuccess(ResponseT r) {
-      super.set(r);
-    }
-
-    @Override
-    public void onFailure(Throwable throwable) {
-      if (throwable instanceof CancellationException && cancelled) {
-        // this just circled around, so ignore.
-        return;
-      } else {
-        setException(exceptionFactory.create(throwable));
-      }
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionClientStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionClientStreamingCallable.java
deleted file mode 100644
index d3a785638..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionClientStreamingCallable.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.StatusCode;
-import java.util.Set;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-final class GrpcExceptionClientStreamingCallable<RequestT, ResponseT>
-    extends ClientStreamingCallable<RequestT, ResponseT> {
-  private final ClientStreamingCallable<RequestT, ResponseT> innerCallable;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  GrpcExceptionClientStreamingCallable(
-      ClientStreamingCallable<RequestT, ResponseT> innerCallable,
-      Set<StatusCode.Code> retryableCodes) {
-    this.innerCallable = innerCallable;
-    this.exceptionFactory = new GrpcApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public ApiStreamObserver<RequestT> clientStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    GrpcExceptionTranslatingStreamObserver<ResponseT> innerObserver =
-        new GrpcExceptionTranslatingStreamObserver<>(responseObserver, exceptionFactory);
-
-    return innerCallable.clientStreamingCall(innerObserver, context);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionServerStreamingCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionServerStreamingCallable.java
deleted file mode 100644
index 088817487..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionServerStreamingCallable.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import java.util.Set;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-class GrpcExceptionServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-  private final ServerStreamingCallable<RequestT, ResponseT> inner;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  public GrpcExceptionServerStreamingCallable(
-      ServerStreamingCallable<RequestT, ResponseT> inner, Set<Code> retryableCodes) {
-    this.inner = inner;
-    this.exceptionFactory = new GrpcApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    inner.call(
-        request, new ExceptionResponseObserver<>(responseObserver, exceptionFactory), context);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionTranslatingStreamObserver.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionTranslatingStreamObserver.java
deleted file mode 100644
index 7725344ed..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcExceptionTranslatingStreamObserver.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiStreamObserver;
-
-/**
- * An {@link ApiStreamObserver} that wraps grpc's errors into {@link
- * com.google.api.gax.rpc.ApiException}s.
- *
- * <p>Package-private for internal use.
- *
- * @param <ResponseT>
- */
-final class GrpcExceptionTranslatingStreamObserver<ResponseT>
-    implements ApiStreamObserver<ResponseT> {
-  private final ApiStreamObserver<ResponseT> innerObserver;
-  private final GrpcApiExceptionFactory exceptionFactory;
-
-  GrpcExceptionTranslatingStreamObserver(
-      ApiStreamObserver<ResponseT> innerObserver, GrpcApiExceptionFactory exceptionFactory) {
-    this.innerObserver = innerObserver;
-    this.exceptionFactory = exceptionFactory;
-  }
-
-  @Override
-  public void onNext(ResponseT value) {
-    innerObserver.onNext(value);
-  }
-
-  @Override
-  public void onError(Throwable t) {
-    innerObserver.onError(exceptionFactory.create(t));
-  }
-
-  @Override
-  public void onCompleted() {
-    innerObserver.onCompleted();
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcHeaderInterceptor.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcHeaderInterceptor.java
deleted file mode 100644
index 9e74538da..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcHeaderInterceptor.java
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import com.google.common.collect.ImmutableMap;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.ForwardingClientCall.SimpleForwardingClientCall;
-import io.grpc.Metadata;
-import io.grpc.Metadata.Key;
-import io.grpc.MethodDescriptor;
-import java.util.Map;
-import java.util.Map.Entry;
-
-/**
- * An interceptor to handle custom headers.
- *
- * <p>Package-private for internal usage.
- */
-@InternalApi
-public class GrpcHeaderInterceptor implements ClientInterceptor {
-  private final Map<Metadata.Key<String>, String> staticHeaders;
-  private final String userAgentHeader;
-
-  public GrpcHeaderInterceptor(Map<String, String> staticHeaders) {
-    ImmutableMap.Builder<Metadata.Key<String>, String> grpcHeaders = ImmutableMap.builder();
-    String userAgentStaticHeader = null;
-    for (Map.Entry<String, String> header : staticHeaders.entrySet()) {
-      Metadata.Key<String> headerKey =
-          Metadata.Key.of(header.getKey(), Metadata.ASCII_STRING_MARSHALLER);
-
-      // User-Agent is overridden on gRPC level. The custom User-Agent is supposed to be provided
-      // differently and only merging with gRPC default value for User-Agent is permitted.
-      // Specifically the User-Agent will be provided via ManagedChannelBuilder#userAgent(String)
-      // during channel construction (calling #getUserAgentHeader() to get the value, initialized
-      // here).
-      if ("user-agent".equals(headerKey.name())) {
-        userAgentStaticHeader = header.getValue();
-      } else {
-        grpcHeaders.put(headerKey, header.getValue());
-      }
-    }
-    this.staticHeaders = grpcHeaders.build();
-    this.userAgentHeader = userAgentStaticHeader;
-  }
-
-  @Override
-  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
-      MethodDescriptor<ReqT, RespT> method, final CallOptions callOptions, Channel next) {
-    ClientCall<ReqT, RespT> call = next.newCall(method, callOptions);
-    return new SimpleForwardingClientCall<ReqT, RespT>(call) {
-      @Override
-      public void start(ClientCall.Listener<RespT> responseListener, Metadata headers) {
-        for (Entry<Key<String>, String> staticHeader : staticHeaders.entrySet()) {
-          headers.put(staticHeader.getKey(), staticHeader.getValue());
-        }
-
-        Map<Key<String>, String> dynamicHeaders =
-            CallOptionsUtil.getDynamicHeadersOption(callOptions);
-        for (Entry<Key<String>, String> dynamicHeader : dynamicHeaders.entrySet()) {
-          headers.put(dynamicHeader.getKey(), dynamicHeader.getValue());
-        }
-
-        super.start(responseListener, headers);
-      }
-    };
-  }
-
-  public String getUserAgentHeader() {
-    return userAgentHeader;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcInterceptorProvider.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcInterceptorProvider.java
deleted file mode 100644
index f3d4de8ba..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcInterceptorProvider.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import io.grpc.ClientInterceptor;
-import java.util.List;
-
-/** Provider of custom gRPC ClientInterceptors. */
-public interface GrpcInterceptorProvider {
-
-  /**
-   * Get the list of client interceptors.
-   *
-   * @return interceptors
-   */
-  List<ClientInterceptor> getInterceptors();
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcLongRunningClient.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcLongRunningClient.java
deleted file mode 100644
index fca5e73b9..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcLongRunningClient.java
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.TranslatingUnaryCallable;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.Operation;
-import com.google.longrunning.stub.OperationsStub;
-import com.google.protobuf.Empty;
-
-/**
- * Implementation of LongRunningClient based on gRPC.
- *
- * <p>Package-private for internal usage.
- */
-class GrpcLongRunningClient implements LongRunningClient {
-  private final OperationsStub operationsStub;
-
-  public GrpcLongRunningClient(OperationsStub operationsStub) {
-    this.operationsStub = operationsStub;
-  }
-
-  @Override
-  public UnaryCallable<String, OperationSnapshot> getOperationCallable() {
-    return TranslatingUnaryCallable.create(
-        operationsStub.getOperationCallable(),
-        new ApiFunction<String, GetOperationRequest>() {
-          @Override
-          public GetOperationRequest apply(String request) {
-            return GetOperationRequest.newBuilder().setName(request).build();
-          }
-        },
-        new ApiFunction<Operation, OperationSnapshot>() {
-          @Override
-          public OperationSnapshot apply(Operation operation) {
-            return GrpcOperationSnapshot.create(operation);
-          }
-        });
-  }
-
-  @Override
-  public UnaryCallable<String, Void> cancelOperationCallable() {
-    return TranslatingUnaryCallable.create(
-        operationsStub.cancelOperationCallable(),
-        new ApiFunction<String, CancelOperationRequest>() {
-          @Override
-          public CancelOperationRequest apply(String request) {
-            return CancelOperationRequest.newBuilder().setName(request).build();
-          }
-        },
-        new ApiFunction<Empty, Void>() {
-          @Override
-          public Void apply(Empty empty) {
-            return null;
-          }
-        });
-  }
-
-  @Override
-  public UnaryCallable<String, Void> deleteOperationCallable() {
-    return TranslatingUnaryCallable.create(
-        operationsStub.deleteOperationCallable(),
-        new ApiFunction<String, DeleteOperationRequest>() {
-          @Override
-          public DeleteOperationRequest apply(String request) {
-            return DeleteOperationRequest.newBuilder().setName(request).build();
-          }
-        },
-        new ApiFunction<Empty, Void>() {
-          @Override
-          public Void apply(Empty empty) {
-            return null;
-          }
-        });
-  }
-
-  public static GrpcLongRunningClient create(OperationsStub operationsStub) {
-    return new GrpcLongRunningClient(operationsStub);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptor.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptor.java
deleted file mode 100644
index c3940f4db..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptor.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.ForwardingClientCall.SimpleForwardingClientCall;
-import io.grpc.ForwardingClientCallListener.SimpleForwardingClientCallListener;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-
-/**
- * An interceptor to handle receiving the response headers.
- *
- * <p>Package-private for internal usage.
- */
-@InternalApi
-class GrpcMetadataHandlerInterceptor implements ClientInterceptor {
-
-  @Override
-  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
-      MethodDescriptor<ReqT, RespT> method, final CallOptions callOptions, Channel next) {
-    ClientCall<ReqT, RespT> call = next.newCall(method, callOptions);
-
-    final ResponseMetadataHandler metadataHandler =
-        CallOptionsUtil.getMetadataHandlerOption(callOptions);
-
-    if (metadataHandler == null) {
-      return call;
-    }
-    return new SimpleForwardingClientCall<ReqT, RespT>(call) {
-      @Override
-      public void start(Listener<RespT> responseListener, Metadata headers) {
-        Listener<RespT> forwardingResponseListener =
-            new SimpleForwardingClientCallListener<RespT>(responseListener) {
-              @Override
-              public void onHeaders(Metadata headers) {
-                super.onHeaders(headers);
-                metadataHandler.onHeaders(headers);
-              }
-
-              @Override
-              public void onClose(Status status, Metadata trailers) {
-                metadataHandler.onTrailers(trailers);
-                super.onClose(status, trailers);
-              }
-            };
-        super.start(forwardingResponseListener, headers);
-      }
-    };
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshot.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshot.java
deleted file mode 100644
index 4483ef1cf..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshot.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.longrunning.Operation;
-import io.grpc.Status;
-
-/**
- * Implementation of OperationSnapshot based on gRPC.
- *
- * <p>Package-private for internal usage.
- */
-class GrpcOperationSnapshot implements OperationSnapshot {
-
-  private final Operation operation;
-
-  public GrpcOperationSnapshot(Operation operation) {
-    this.operation = operation;
-  }
-
-  @Override
-  public String getName() {
-    return operation.getName();
-  }
-
-  @Override
-  public Object getMetadata() {
-    return operation.getMetadata();
-  }
-
-  @Override
-  public boolean isDone() {
-    return operation.getDone();
-  }
-
-  @Override
-  public Object getResponse() {
-    return operation.getResponse();
-  }
-
-  @Override
-  public StatusCode getErrorCode() {
-    return GrpcStatusCode.of(Status.fromCodeValue(operation.getError().getCode()).getCode());
-  }
-
-  @Override
-  public String getErrorMessage() {
-    return operation.getError().getMessage();
-  }
-
-  public static GrpcOperationSnapshot create(Operation operation) {
-    return new GrpcOperationSnapshot(operation);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshotCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshotCallable.java
deleted file mode 100644
index a7f467a99..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcOperationSnapshotCallable.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.Operation;
-
-/**
- * A {@code UnaryCallable} that wraps a UnaryCallable returning an Operation and returns an
- * OperationSnapshot instead.
- *
- * <p>Package-private for internal usage.
- */
-class GrpcOperationSnapshotCallable<RequestT> extends UnaryCallable<RequestT, OperationSnapshot> {
-  private final UnaryCallable<RequestT, Operation> innerCallable;
-
-  public GrpcOperationSnapshotCallable(UnaryCallable<RequestT, Operation> innerCallable) {
-    this.innerCallable = innerCallable;
-  }
-
-  @Override
-  public ApiFuture<OperationSnapshot> futureCall(RequestT request, ApiCallContext context) {
-    return ApiFutures.transform(
-        innerCallable.futureCall(request, context),
-        new ApiFunction<Operation, OperationSnapshot>() {
-          @Override
-          public OperationSnapshot apply(Operation operation) {
-            return new GrpcOperationSnapshot(operation);
-          }
-        },
-        directExecutor());
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcRawCallableFactory.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcRawCallableFactory.java
deleted file mode 100644
index 1375fe9fb..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcRawCallableFactory.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.UnaryCallable;
-import java.util.Set;
-
-/** Class with utility methods to create low level grpc-based direct callables. */
-@InternalApi("For internal use by google-cloud-java clients only")
-public class GrpcRawCallableFactory {
-  private GrpcRawCallableFactory() {}
-
-  /**
-   * Create a Unary callable object with minimal grpc-specific functionality.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param retryableCodes the {@link StatusCode.Code} that should be marked as retryable
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings, Set<StatusCode.Code> retryableCodes) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        new GrpcDirectCallable<>(
-            grpcCallSettings.getMethodDescriptor(), grpcCallSettings.shouldAwaitTrailers());
-
-    if (grpcCallSettings.getParamsExtractor() != null) {
-      callable =
-          new GrpcUnaryRequestParamCallable<>(callable, grpcCallSettings.getParamsExtractor());
-    }
-    return new GrpcExceptionCallable<>(callable, retryableCodes);
-  }
-
-  /**
-   * Create a bidirectional streaming callable object with grpc-specific functionality. Designed for
-   * use by generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param retryableCodes the {@link StatusCode.Code} that should be marked as retryable
-   * @return {@link BidiStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          Set<StatusCode.Code> retryableCodes) {
-    BidiStreamingCallable<RequestT, ResponseT> callable =
-        new GrpcDirectBidiStreamingCallable<>(grpcCallSettings.getMethodDescriptor());
-
-    return new GrpcExceptionBidiStreamingCallable<>(callable, retryableCodes);
-  }
-
-  /**
-   * Create a server-streaming callable with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param retryableCodes the {@link StatusCode.Code} that should be marked as retryable
-   */
-  public static <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          Set<StatusCode.Code> retryableCodes) {
-    ServerStreamingCallable<RequestT, ResponseT> callable =
-        new GrpcDirectServerStreamingCallable<>(grpcCallSettings.getMethodDescriptor());
-    if (grpcCallSettings.getParamsExtractor() != null) {
-      callable =
-          new GrpcServerStreamingRequestParamCallable<>(
-              callable, grpcCallSettings.getParamsExtractor());
-    }
-    return new GrpcExceptionServerStreamingCallable<>(callable, retryableCodes);
-  }
-  /**
-   * Create a client-streaming callable object with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param retryableCodes the {@link StatusCode.Code} that should be marked as retryable
-   */
-  public static <RequestT, ResponseT>
-      ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          Set<StatusCode.Code> retryableCodes) {
-    ClientStreamingCallable<RequestT, ResponseT> callable =
-        new GrpcDirectClientStreamingCallable<>(grpcCallSettings.getMethodDescriptor());
-
-    return new GrpcExceptionClientStreamingCallable<>(callable, retryableCodes);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcResponseMetadata.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcResponseMetadata.java
deleted file mode 100644
index 9e018eefb..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcResponseMetadata.java
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.common.base.Preconditions;
-import io.grpc.Metadata;
-
-/**
- * GrpcResponseMetadata provides a mechanism to access the headers and trailers returned by a gRPC
- * client method.
- *
- * <p>NOTE: the GrpcResponseMetadata class is not thread-safe and should NOT be re-used for multiple
- * calls. A new instance of GrpcResponseMetadata should be constructed for each call that requires
- * metadata to be accessed.
- *
- * <p>Example usage:
- *
- * <pre>
- * <code>
- * GrpcResponseMetadata grpcResponseMetadata = new GrpcResponseMetadata();
- * Foo foo = client.getFooCallable().call(getFooRequest, grpcResponseMetadata.createContextWithHandlers());
- * Metadata headers = grpcResponseMetadata.getMetadata();
- * Metadata trailers = grpcResponseMetadata.getTrailingMetadata();
- * </code>
- * </pre>
- */
-public class GrpcResponseMetadata implements ResponseMetadataHandler {
-
-  private volatile Metadata responseMetadata;
-  private volatile Metadata trailingMetadata;
-
-  /**
-   * Constructs a new call context from an existing ApiCallContext, and sets the CallOptions to add
-   * handlers to retrieve the headers and trailers, and make them available via the getMetadata and
-   * getTrailingMetadata methods.
-   */
-  public GrpcCallContext addHandlers(ApiCallContext apiCallContext) {
-    if (Preconditions.checkNotNull(apiCallContext) instanceof GrpcCallContext) {
-      return addHandlers((GrpcCallContext) apiCallContext);
-    }
-    throw new IllegalArgumentException(
-        "context must be an instance of GrpcCallContext, but found "
-            + apiCallContext.getClass().getName());
-  }
-
-  /**
-   * Constructs a new call context and sets the CallOptions to add handlers to retrieve the headers
-   * and trailers, and make them available via the getMetadata and getTrailingMetadata methods.
-   */
-  public GrpcCallContext createContextWithHandlers() {
-    return addHandlers(GrpcCallContext.createDefault());
-  }
-
-  private GrpcCallContext addHandlers(GrpcCallContext grpcCallContext) {
-    return Preconditions.checkNotNull(grpcCallContext)
-        .withCallOptions(
-            CallOptionsUtil.putMetadataHandlerOption(grpcCallContext.getCallOptions(), this));
-  }
-
-  /**
-   * Returns the headers from the gRPC method as Metadata. If the call has not completed, will
-   * return null.
-   */
-  public Metadata getMetadata() {
-    return responseMetadata;
-  }
-
-  /**
-   * Returns the trailers from the gRPC method as Metadata. If the call has not completed, will
-   * return null.
-   */
-  public Metadata getTrailingMetadata() {
-    return trailingMetadata;
-  }
-
-  @Override
-  public void onHeaders(Metadata metadata) {
-    responseMetadata = metadata;
-  }
-
-  @Override
-  public void onTrailers(Metadata metadata) {
-    trailingMetadata = metadata;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcServerStreamingRequestParamCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcServerStreamingRequestParamCallable.java
deleted file mode 100644
index 5e0a59851..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcServerStreamingRequestParamCallable.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import com.google.api.gax.rpc.RequestUrlParamsEncoder;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.common.base.Preconditions;
-
-/**
- * A {@code ServerStreamingCallable} that extracts values from the fields of the request and inserts
- * them into headers.
- *
- * <p>Package-private for internal usage.
- */
-class GrpcServerStreamingRequestParamCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-  private final ServerStreamingCallable<RequestT, ResponseT> callable;
-  private final RequestUrlParamsEncoder<RequestT> paramsEncoder;
-
-  GrpcServerStreamingRequestParamCallable(
-      ServerStreamingCallable<RequestT, ResponseT> callable,
-      RequestParamsExtractor<RequestT> paramsExtractor) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.paramsEncoder =
-        new RequestUrlParamsEncoder<>(Preconditions.checkNotNull(paramsExtractor), false);
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-    callable.call(request, responseObserver, contextWithParamsEncoder(request, context));
-  }
-
-  private ApiCallContext contextWithParamsEncoder(RequestT request, ApiCallContext inputContext) {
-    return GrpcCallContext.createDefault()
-        .nullToSelf(inputContext)
-        .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStatusCode.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStatusCode.java
deleted file mode 100644
index b3db79eda..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStatusCode.java
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.auto.value.AutoValue;
-import io.grpc.Status;
-
-/** A failure code specific to a gRPC call. */
-@InternalExtensionOnly
-@AutoValue
-public abstract class GrpcStatusCode implements StatusCode {
-  /** Creates a new instance with the given {@link Status.Code}. */
-  public static GrpcStatusCode of(Status.Code grpcCode) {
-    return new AutoValue_GrpcStatusCode(grpcCode);
-  }
-
-  static StatusCode.Code grpcCodeToStatusCode(Status.Code code) {
-    switch (code) {
-      case OK:
-        return StatusCode.Code.OK;
-      case CANCELLED:
-        return StatusCode.Code.CANCELLED;
-      case UNKNOWN:
-        return StatusCode.Code.UNKNOWN;
-      case INVALID_ARGUMENT:
-        return StatusCode.Code.INVALID_ARGUMENT;
-      case DEADLINE_EXCEEDED:
-        return StatusCode.Code.DEADLINE_EXCEEDED;
-      case NOT_FOUND:
-        return StatusCode.Code.NOT_FOUND;
-      case ALREADY_EXISTS:
-        return StatusCode.Code.ALREADY_EXISTS;
-      case PERMISSION_DENIED:
-        return StatusCode.Code.PERMISSION_DENIED;
-      case RESOURCE_EXHAUSTED:
-        return StatusCode.Code.RESOURCE_EXHAUSTED;
-      case FAILED_PRECONDITION:
-        return StatusCode.Code.FAILED_PRECONDITION;
-      case ABORTED:
-        return StatusCode.Code.ABORTED;
-      case OUT_OF_RANGE:
-        return StatusCode.Code.OUT_OF_RANGE;
-      case UNIMPLEMENTED:
-        return StatusCode.Code.UNIMPLEMENTED;
-      case INTERNAL:
-        return StatusCode.Code.INTERNAL;
-      case UNAVAILABLE:
-        return StatusCode.Code.UNAVAILABLE;
-      case DATA_LOSS:
-        return StatusCode.Code.DATA_LOSS;
-      case UNAUTHENTICATED:
-        return StatusCode.Code.UNAUTHENTICATED;
-      default:
-        throw new IllegalStateException("Unrecognized status code: " + code);
-    }
-  }
-
-  /** Returns the {@link Status.Code} from grpc. */
-  @Override
-  public StatusCode.Code getCode() {
-    return grpcCodeToStatusCode(getTransportCode());
-  }
-
-  @Override
-  public abstract Status.Code getTransportCode();
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStubCallableFactory.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStubCallableFactory.java
deleted file mode 100644
index 131dafc1f..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcStubCallableFactory.java
+++ /dev/null
@@ -1,150 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.Operation;
-import com.google.longrunning.stub.OperationsStub;
-
-public interface GrpcStubCallableFactory {
-
-  /**
-   * Create a callable object with grpc-specific functionality. Designed for use by generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   */
-  <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext);
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext);
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext);
-
-  /**
-   * Creates a callable object that represents a long-running operation. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param operationCallSettings {@link OperationCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @param operationsStub {@link OperationsStub} to use to poll for updates on the Operation.
-   * @return {@link OperationCallable} callable object.
-   */
-  <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          GrpcCallSettings<RequestT, Operation> grpcCallSettings,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          OperationsStub operationsStub);
-
-  /**
-   * Create a bidirectional streaming callable object with grpc-specific functionality. Designed for
-   * use by generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link BidiStreamingCallable} callable object.
-   */
-  <RequestT, ResponseT> BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-      ClientContext clientContext);
-
-  /**
-   * Create a server-streaming callable with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   */
-  <RequestT, ResponseT> ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      ServerStreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-      ClientContext clientContext);
-
-  /**
-   * Create a client-streaming callable object with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param grpcCallSettings the gRPC call settings
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link ClientStreamingCallable} callable object.
-   */
-  <RequestT, ResponseT> ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-      ClientContext clientContext);
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcTransportChannel.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcTransportChannel.java
deleted file mode 100644
index 9e63bb2a6..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcTransportChannel.java
+++ /dev/null
@@ -1,116 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.core.ResourceCloseException;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.auto.value.AutoValue;
-import io.grpc.Channel;
-import io.grpc.ManagedChannel;
-import java.util.concurrent.TimeUnit;
-
-/** Implementation of TransportChannel based on gRPC. */
-@AutoValue
-@InternalExtensionOnly
-public abstract class GrpcTransportChannel implements TransportChannel {
-
-  /** The name of the Grpc transport. */
-  public static String getGrpcTransportName() {
-    return "grpc";
-  }
-
-  @Override
-  public String getTransportName() {
-    return getGrpcTransportName();
-  }
-
-  @Override
-  public GrpcCallContext getEmptyCallContext() {
-    return GrpcCallContext.createDefault();
-  }
-
-  /** The channel in use. */
-  abstract ManagedChannel getManagedChannel();
-
-  public Channel getChannel() {
-    return getManagedChannel();
-  }
-
-  @Override
-  public void shutdown() {
-    getManagedChannel().shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return getManagedChannel().isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return getManagedChannel().isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    getManagedChannel().shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return getManagedChannel().awaitTermination(duration, unit);
-  }
-
-  @Override
-  public void close() {
-    getManagedChannel().shutdown();
-    try {
-      awaitTermination(6, TimeUnit.MINUTES);
-    } catch (InterruptedException e) {
-      throw new ResourceCloseException(e);
-    }
-  }
-
-  public static Builder newBuilder() {
-    return new AutoValue_GrpcTransportChannel.Builder();
-  }
-
-  public static GrpcTransportChannel create(ManagedChannel channel) {
-    return newBuilder().setManagedChannel(channel).build();
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setManagedChannel(ManagedChannel value);
-
-    public abstract GrpcTransportChannel build();
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcUnaryRequestParamCallable.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcUnaryRequestParamCallable.java
deleted file mode 100644
index 9eb78aca0..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcUnaryRequestParamCallable.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import com.google.api.gax.rpc.RequestUrlParamsEncoder;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-
-/**
- * A {@code UnaryCallable} that extracts values from the fields of the request and inserts them into
- * headers.
- *
- * <p>Package-private for internal usage.
- */
-class GrpcUnaryRequestParamCallable<RequestT, ResponseT>
-    extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final RequestUrlParamsEncoder<RequestT> paramsEncoder;
-
-  GrpcUnaryRequestParamCallable(
-      UnaryCallable<RequestT, ResponseT> callable,
-      RequestParamsExtractor<RequestT> paramsExtractor) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.paramsEncoder =
-        new RequestUrlParamsEncoder<>(Preconditions.checkNotNull(paramsExtractor), false);
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    GrpcCallContext newCallContext =
-        GrpcCallContext.createDefault()
-            .nullToSelf(inputContext)
-            .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));
-
-    return callable.futureCall(request, newCallContext);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java
deleted file mode 100644
index 40e2bd139..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java
+++ /dev/null
@@ -1,753 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.rpc.FixedHeaderProvider;
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.internal.EnvironmentProvider;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.ComputeEngineCredentials;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.io.Files;
-import io.grpc.CallCredentials;
-import io.grpc.ChannelCredentials;
-import io.grpc.Grpc;
-import io.grpc.ManagedChannel;
-import io.grpc.ManagedChannelBuilder;
-import io.grpc.TlsChannelCredentials;
-import io.grpc.alts.GoogleDefaultChannelCredentials;
-import io.grpc.auth.MoreCallCredentials;
-import java.io.File;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.security.GeneralSecurityException;
-import java.security.KeyStore;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
-import javax.net.ssl.KeyManagerFactory;
-import org.threeten.bp.Duration;
-
-/**
- * InstantiatingGrpcChannelProvider is a TransportChannelProvider which constructs a gRPC
- * ManagedChannel with a number of configured inputs every time getChannel(...) is called. These
- * inputs include a port, a service address, and credentials.
- *
- * <p>The credentials can either be supplied directly (by providing a FixedCredentialsProvider to
- * Builder.setCredentialsProvider()) or acquired implicitly from Application Default Credentials (by
- * providing a GoogleCredentialsProvider to Builder.setCredentialsProvider()).
- *
- * <p>The client lib header and generator header values are used to form a value that goes into the
- * http header of requests to the service.
- */
-@InternalExtensionOnly
-public final class InstantiatingGrpcChannelProvider implements TransportChannelProvider {
-  static final String DIRECT_PATH_ENV_VAR = "GOOGLE_CLOUD_ENABLE_DIRECT_PATH";
-  private static final String DIRECT_PATH_ENV_DISABLE_DIRECT_PATH =
-      "GOOGLE_CLOUD_DISABLE_DIRECT_PATH";
-  private static final String DIRECT_PATH_ENV_ENABLE_XDS = "GOOGLE_CLOUD_ENABLE_DIRECT_PATH_XDS";
-  static final long DIRECT_PATH_KEEP_ALIVE_TIME_SECONDS = 3600;
-  static final long DIRECT_PATH_KEEP_ALIVE_TIMEOUT_SECONDS = 20;
-  static final String GCE_PRODUCTION_NAME_PRIOR_2016 = "Google";
-  static final String GCE_PRODUCTION_NAME_AFTER_2016 = "Google Compute Engine";
-
-  private final int processorCount;
-  private final Executor executor;
-  private final HeaderProvider headerProvider;
-  private final String endpoint;
-  // TODO: remove. envProvider currently provides DirectPath environment variable, and is only used
-  // during initial rollout for DirectPath. This provider will be removed once the DirectPath
-  // environment is not used.
-  private final EnvironmentProvider envProvider;
-  @Nullable private final GrpcInterceptorProvider interceptorProvider;
-  @Nullable private final Integer maxInboundMessageSize;
-  @Nullable private final Integer maxInboundMetadataSize;
-  @Nullable private final Duration keepAliveTime;
-  @Nullable private final Duration keepAliveTimeout;
-  @Nullable private final Boolean keepAliveWithoutCalls;
-  private final ChannelPoolSettings channelPoolSettings;
-  @Nullable private final Credentials credentials;
-  @Nullable private final ChannelPrimer channelPrimer;
-  @Nullable private final Boolean attemptDirectPath;
-  @Nullable private final Boolean allowNonDefaultServiceAccount;
-  @VisibleForTesting final ImmutableMap<String, ?> directPathServiceConfig;
-  @Nullable private final MtlsProvider mtlsProvider;
-
-  @Nullable
-  private final ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator;
-
-  private InstantiatingGrpcChannelProvider(Builder builder) {
-    this.processorCount = builder.processorCount;
-    this.executor = builder.executor;
-    this.headerProvider = builder.headerProvider;
-    this.endpoint = builder.endpoint;
-    this.mtlsProvider = builder.mtlsProvider;
-    this.envProvider = builder.envProvider;
-    this.interceptorProvider = builder.interceptorProvider;
-    this.maxInboundMessageSize = builder.maxInboundMessageSize;
-    this.maxInboundMetadataSize = builder.maxInboundMetadataSize;
-    this.keepAliveTime = builder.keepAliveTime;
-    this.keepAliveTimeout = builder.keepAliveTimeout;
-    this.keepAliveWithoutCalls = builder.keepAliveWithoutCalls;
-    this.channelPoolSettings = builder.channelPoolSettings;
-    this.channelConfigurator = builder.channelConfigurator;
-    this.credentials = builder.credentials;
-    this.channelPrimer = builder.channelPrimer;
-    this.attemptDirectPath = builder.attemptDirectPath;
-    this.allowNonDefaultServiceAccount = builder.allowNonDefaultServiceAccount;
-    this.directPathServiceConfig =
-        builder.directPathServiceConfig == null
-            ? getDefaultDirectPathServiceConfig()
-            : builder.directPathServiceConfig;
-  }
-
-  /**
-   * @deprecated If executor is not set, this channel provider will create channels with default
-   *     grpc executor.
-   */
-  @Deprecated
-  @Override
-  public boolean needsExecutor() {
-    return executor == null;
-  }
-
-  @Deprecated
-  @Override
-  public TransportChannelProvider withExecutor(ScheduledExecutorService executor) {
-    return withExecutor((Executor) executor);
-  }
-
-  @Override
-  public TransportChannelProvider withExecutor(Executor executor) {
-    return toBuilder().setExecutor(executor).build();
-  }
-
-  @Override
-  public boolean needsHeaders() {
-    return headerProvider == null;
-  }
-
-  @Override
-  public TransportChannelProvider withHeaders(Map<String, String> headers) {
-    return toBuilder().setHeaderProvider(FixedHeaderProvider.create(headers)).build();
-  }
-
-  @Override
-  public String getTransportName() {
-    return GrpcTransportChannel.getGrpcTransportName();
-  }
-
-  @Override
-  public boolean needsEndpoint() {
-    return endpoint == null;
-  }
-
-  /**
-   * Specify the endpoint the channel should connect to.
-   *
-   * <p>The value of {@code endpoint} must be of the form {@code host:port}.
-   *
-   * @param endpoint The endpoint to connect to
-   * @return A new {@link InstantiatingGrpcChannelProvider} with the specified endpoint configured
-   */
-  @Override
-  public TransportChannelProvider withEndpoint(String endpoint) {
-    validateEndpoint(endpoint);
-    return toBuilder().setEndpoint(endpoint).build();
-  }
-
-  /** @deprecated Please modify pool settings via {@link #toBuilder()} */
-  @Deprecated
-  @Override
-  public boolean acceptsPoolSize() {
-    return true;
-  }
-
-  /** @deprecated Please modify pool settings via {@link #toBuilder()} */
-  @Deprecated
-  @Override
-  public TransportChannelProvider withPoolSize(int size) {
-    return toBuilder().setPoolSize(size).build();
-  }
-
-  @Override
-  public boolean needsCredentials() {
-    return credentials == null;
-  }
-
-  @Override
-  public TransportChannelProvider withCredentials(Credentials credentials) {
-    return toBuilder().setCredentials(credentials).build();
-  }
-
-  @Override
-  public TransportChannel getTransportChannel() throws IOException {
-    if (needsHeaders()) {
-      throw new IllegalStateException("getTransportChannel() called when needsHeaders() is true");
-    } else if (needsEndpoint()) {
-      throw new IllegalStateException("getTransportChannel() called when needsEndpoint() is true");
-    } else {
-      return createChannel();
-    }
-  }
-
-  private TransportChannel createChannel() throws IOException {
-    return GrpcTransportChannel.create(
-        ChannelPool.create(
-            channelPoolSettings, InstantiatingGrpcChannelProvider.this::createSingleChannel));
-  }
-
-  // TODO(mohanli): Use attemptDirectPath as the only indicator once setAttemptDirectPath is adapted
-  //                and the env var is removed from client environment.
-  private boolean isDirectPathEnabled(String serviceAddress) {
-    String disableDirectPathEnv = envProvider.getenv(DIRECT_PATH_ENV_DISABLE_DIRECT_PATH);
-    boolean isDirectPathDisabled = Boolean.parseBoolean(disableDirectPathEnv);
-    if (isDirectPathDisabled) {
-      return false;
-    }
-    // Only check attemptDirectPath when DIRECT_PATH_ENV_DISABLE_DIRECT_PATH is not set.
-    if (attemptDirectPath != null) {
-      return attemptDirectPath;
-    }
-    // Only check DIRECT_PATH_ENV_VAR when attemptDirectPath is not set.
-    String whiteList = envProvider.getenv(DIRECT_PATH_ENV_VAR);
-    if (whiteList == null) {
-      return false;
-    }
-    for (String service : whiteList.split(",")) {
-      if (!service.isEmpty() && serviceAddress.contains(service)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  private boolean isNonDefaultServiceAccountAllowed() {
-    if (allowNonDefaultServiceAccount != null && allowNonDefaultServiceAccount) {
-      return true;
-    }
-    return credentials instanceof ComputeEngineCredentials;
-  }
-
-  // DirectPath should only be used on Compute Engine.
-  // Notice Windows is supported for now.
-  static boolean isOnComputeEngine() {
-    String osName = System.getProperty("os.name");
-    if ("Linux".equals(osName)) {
-      try {
-        String result =
-            Files.asCharSource(new File("/sys/class/dmi/id/product_name"), StandardCharsets.UTF_8)
-                .readFirstLine();
-        return result.contains(GCE_PRODUCTION_NAME_PRIOR_2016)
-            || result.contains(GCE_PRODUCTION_NAME_AFTER_2016);
-      } catch (IOException ignored) {
-        return false;
-      }
-    }
-    return false;
-  }
-
-  @VisibleForTesting
-  ChannelCredentials createMtlsChannelCredentials() throws IOException, GeneralSecurityException {
-    if (mtlsProvider.useMtlsClientCertificate()) {
-      KeyStore mtlsKeyStore = mtlsProvider.getKeyStore();
-      if (mtlsKeyStore != null) {
-        KeyManagerFactory factory =
-            KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
-        factory.init(mtlsKeyStore, new char[] {});
-        return TlsChannelCredentials.newBuilder().keyManager(factory.getKeyManagers()).build();
-      }
-    }
-    return null;
-  }
-
-  private ManagedChannel createSingleChannel() throws IOException {
-    GrpcHeaderInterceptor headerInterceptor =
-        new GrpcHeaderInterceptor(headerProvider.getHeaders());
-    GrpcMetadataHandlerInterceptor metadataHandlerInterceptor =
-        new GrpcMetadataHandlerInterceptor();
-
-    int colon = endpoint.lastIndexOf(':');
-    if (colon < 0) {
-      throw new IllegalStateException("invalid endpoint - should have been validated: " + endpoint);
-    }
-    int port = Integer.parseInt(endpoint.substring(colon + 1));
-    String serviceAddress = endpoint.substring(0, colon);
-
-    ManagedChannelBuilder<?> builder;
-
-    // Check DirectPath traffic.
-    boolean isDirectPathXdsEnabled = false;
-    if (isDirectPathEnabled(serviceAddress)
-        && isNonDefaultServiceAccountAllowed()
-        && isOnComputeEngine()) {
-      CallCredentials callCreds = MoreCallCredentials.from(credentials);
-      ChannelCredentials channelCreds =
-          GoogleDefaultChannelCredentials.newBuilder().callCredentials(callCreds).build();
-      isDirectPathXdsEnabled = Boolean.parseBoolean(envProvider.getenv(DIRECT_PATH_ENV_ENABLE_XDS));
-      if (isDirectPathXdsEnabled) {
-        // google-c2p: CloudToProd(C2P) Directpath. This scheme is defined in
-        // io.grpc.googleapis.GoogleCloudToProdNameResolverProvider.
-        // This resolver target must not have a port number.
-        builder = Grpc.newChannelBuilder("google-c2p:///" + serviceAddress, channelCreds);
-      } else {
-        builder = Grpc.newChannelBuilderForAddress(serviceAddress, port, channelCreds);
-        builder.defaultServiceConfig(directPathServiceConfig);
-      }
-      // Set default keepAliveTime and keepAliveTimeout when directpath environment is enabled.
-      // Will be overridden by user defined values if any.
-      builder.keepAliveTime(DIRECT_PATH_KEEP_ALIVE_TIME_SECONDS, TimeUnit.SECONDS);
-      builder.keepAliveTimeout(DIRECT_PATH_KEEP_ALIVE_TIMEOUT_SECONDS, TimeUnit.SECONDS);
-    } else {
-      ChannelCredentials channelCredentials;
-      try {
-        channelCredentials = createMtlsChannelCredentials();
-      } catch (GeneralSecurityException e) {
-        throw new IOException(e);
-      }
-      if (channelCredentials != null) {
-        builder = Grpc.newChannelBuilder(endpoint, channelCredentials);
-      } else {
-        builder = ManagedChannelBuilder.forAddress(serviceAddress, port);
-      }
-    }
-    // google-c2p resolver requires service config lookup
-    if (!isDirectPathXdsEnabled) {
-      // See https://github.com/googleapis/gapic-generator/issues/2816
-      builder.disableServiceConfigLookUp();
-    }
-    builder =
-        builder
-            .intercept(new GrpcChannelUUIDInterceptor())
-            .intercept(headerInterceptor)
-            .intercept(metadataHandlerInterceptor)
-            .userAgent(headerInterceptor.getUserAgentHeader())
-            .executor(executor);
-
-    if (maxInboundMetadataSize != null) {
-      builder.maxInboundMetadataSize(maxInboundMetadataSize);
-    }
-    if (maxInboundMessageSize != null) {
-      builder.maxInboundMessageSize(maxInboundMessageSize);
-    }
-    if (keepAliveTime != null) {
-      builder.keepAliveTime(keepAliveTime.toMillis(), TimeUnit.MILLISECONDS);
-    }
-    if (keepAliveTimeout != null) {
-      builder.keepAliveTimeout(keepAliveTimeout.toMillis(), TimeUnit.MILLISECONDS);
-    }
-    if (keepAliveWithoutCalls != null) {
-      builder.keepAliveWithoutCalls(keepAliveWithoutCalls);
-    }
-    if (interceptorProvider != null) {
-      builder.intercept(interceptorProvider.getInterceptors());
-    }
-    if (channelConfigurator != null) {
-      builder = channelConfigurator.apply(builder);
-    }
-
-    ManagedChannel managedChannel = builder.build();
-    if (channelPrimer != null) {
-      channelPrimer.primeChannel(managedChannel);
-    }
-    return managedChannel;
-  }
-
-  /** The endpoint to be used for the channel. */
-  public String getEndpoint() {
-    return endpoint;
-  }
-
-  /** The time without read activity before sending a keepalive ping. */
-  public Duration getKeepAliveTime() {
-    return keepAliveTime;
-  }
-
-  /** The time without read activity after sending a keepalive ping. */
-  public Duration getKeepAliveTimeout() {
-    return keepAliveTimeout;
-  }
-
-  /** Whether keepalive will be performed when there are no outstanding RPCs. */
-  public Boolean getKeepAliveWithoutCalls() {
-    return keepAliveWithoutCalls;
-  }
-
-  /** The maximum metadata size allowed to be received on the channel. */
-  @BetaApi("The surface for maximum metadata size is not stable yet and may change in the future.")
-  public Integer getMaxInboundMetadataSize() {
-    return maxInboundMetadataSize;
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return true;
-  }
-
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  public static Builder newBuilder() {
-    return new Builder();
-  }
-
-  public static final class Builder {
-    @Deprecated private int processorCount;
-    private Executor executor;
-    private HeaderProvider headerProvider;
-    private String endpoint;
-    private EnvironmentProvider envProvider;
-    private MtlsProvider mtlsProvider = new MtlsProvider();
-    @Nullable private GrpcInterceptorProvider interceptorProvider;
-    @Nullable private Integer maxInboundMessageSize;
-    @Nullable private Integer maxInboundMetadataSize;
-    @Nullable private Duration keepAliveTime;
-    @Nullable private Duration keepAliveTimeout;
-    @Nullable private Boolean keepAliveWithoutCalls;
-    @Nullable private ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator;
-    @Nullable private Credentials credentials;
-    @Nullable private ChannelPrimer channelPrimer;
-    private ChannelPoolSettings channelPoolSettings;
-    @Nullable private Boolean attemptDirectPath;
-    @Nullable private Boolean allowNonDefaultServiceAccount;
-    @Nullable private ImmutableMap<String, ?> directPathServiceConfig;
-
-    private Builder() {
-      processorCount = Runtime.getRuntime().availableProcessors();
-      envProvider = System::getenv;
-      channelPoolSettings = ChannelPoolSettings.staticallySized(1);
-    }
-
-    private Builder(InstantiatingGrpcChannelProvider provider) {
-      this.processorCount = provider.processorCount;
-      this.executor = provider.executor;
-      this.headerProvider = provider.headerProvider;
-      this.endpoint = provider.endpoint;
-      this.envProvider = provider.envProvider;
-      this.interceptorProvider = provider.interceptorProvider;
-      this.maxInboundMessageSize = provider.maxInboundMessageSize;
-      this.maxInboundMetadataSize = provider.maxInboundMetadataSize;
-      this.keepAliveTime = provider.keepAliveTime;
-      this.keepAliveTimeout = provider.keepAliveTimeout;
-      this.keepAliveWithoutCalls = provider.keepAliveWithoutCalls;
-      this.channelConfigurator = provider.channelConfigurator;
-      this.credentials = provider.credentials;
-      this.channelPrimer = provider.channelPrimer;
-      this.channelPoolSettings = provider.channelPoolSettings;
-      this.attemptDirectPath = provider.attemptDirectPath;
-      this.allowNonDefaultServiceAccount = provider.allowNonDefaultServiceAccount;
-      this.directPathServiceConfig = provider.directPathServiceConfig;
-      this.mtlsProvider = provider.mtlsProvider;
-    }
-
-    /**
-     * Sets the number of available CPUs, used internally for testing.
-     *
-     * @deprecated CPU based channel scaling is deprecated, please use RPC based scaling instead via
-     *     {@link Builder#setChannelPoolSettings(ChannelPoolSettings)}
-     */
-    @Deprecated
-    Builder setProcessorCount(int processorCount) {
-      this.processorCount = processorCount;
-      return this;
-    }
-
-    /**
-     * Sets the Executor for this TransportChannelProvider.
-     *
-     * <p>This is optional; if it is not provided, needsExecutor() will return true, meaning that an
-     * Executor must be provided when getChannel is called on the constructed
-     * TransportChannelProvider instance. Note: GrpcTransportProvider will automatically provide its
-     * own Executor in this circumstance when it calls getChannel.
-     */
-    public Builder setExecutor(Executor executor) {
-      this.executor = executor;
-      return this;
-    }
-
-    /** @deprecated Please use {@link #setExecutor(Executor)}. */
-    @Deprecated
-    public Builder setExecutorProvider(ExecutorProvider executorProvider) {
-      return setExecutor((Executor) executorProvider.getExecutor());
-    }
-
-    /**
-     * Sets the HeaderProvider for this TransportChannelProvider.
-     *
-     * <p>This is optional; if it is not provided, needsHeaders() will return true, meaning that
-     * headers must be provided when getChannel is called on the constructed
-     * TransportChannelProvider instance.
-     */
-    public Builder setHeaderProvider(HeaderProvider headerProvider) {
-      this.headerProvider = headerProvider;
-      return this;
-    }
-
-    /** Sets the endpoint used to reach the service, eg "localhost:8080". */
-    public Builder setEndpoint(String endpoint) {
-      validateEndpoint(endpoint);
-      this.endpoint = endpoint;
-      return this;
-    }
-
-    @VisibleForTesting
-    Builder setMtlsProvider(MtlsProvider mtlsProvider) {
-      this.mtlsProvider = mtlsProvider;
-      return this;
-    }
-
-    /**
-     * Sets the GrpcInterceptorProvider for this TransportChannelProvider.
-     *
-     * <p>The provider will be called once for each underlying gRPC ManagedChannel that is created.
-     * It is recommended to return a new list of new interceptors on each call so that interceptors
-     * are not shared among channels, but this is not required.
-     */
-    public Builder setInterceptorProvider(GrpcInterceptorProvider interceptorProvider) {
-      this.interceptorProvider = interceptorProvider;
-      return this;
-    }
-
-    public String getEndpoint() {
-      return endpoint;
-    }
-
-    /** The maximum message size allowed to be received on the channel. */
-    public Builder setMaxInboundMessageSize(Integer max) {
-      this.maxInboundMessageSize = max;
-      return this;
-    }
-
-    /** The maximum message size allowed to be received on the channel. */
-    public Integer getMaxInboundMessageSize() {
-      return maxInboundMessageSize;
-    }
-
-    /** The maximum metadata size allowed to be received on the channel. */
-    @BetaApi(
-        "The surface for maximum metadata size is not stable yet and may change in the future.")
-    public Builder setMaxInboundMetadataSize(Integer max) {
-      this.maxInboundMetadataSize = max;
-      return this;
-    }
-
-    /** The maximum metadata size allowed to be received on the channel. */
-    @BetaApi(
-        "The surface for maximum metadata size is not stable yet and may change in the future.")
-    public Integer getMaxInboundMetadataSize() {
-      return maxInboundMetadataSize;
-    }
-
-    /** The time without read activity before sending a keepalive ping. */
-    public Builder setKeepAliveTime(Duration duration) {
-      this.keepAliveTime = duration;
-      return this;
-    }
-
-    /** The time without read activity before sending a keepalive ping. */
-    public Duration getKeepAliveTime() {
-      return keepAliveTime;
-    }
-
-    /** The time without read activity after sending a keepalive ping. */
-    public Builder setKeepAliveTimeout(Duration duration) {
-      this.keepAliveTimeout = duration;
-      return this;
-    }
-
-    /** The time without read activity after sending a keepalive ping. */
-    public Duration getKeepAliveTimeout() {
-      return keepAliveTimeout;
-    }
-
-    /** Whether keepalive will be performed when there are no outstanding RPCs. */
-    public Builder setKeepAliveWithoutCalls(Boolean keepalive) {
-      this.keepAliveWithoutCalls = keepalive;
-      return this;
-    }
-
-    /** Whether keepalive will be performed when there are no outstanding RPCs. */
-    public Boolean getKeepAliveWithoutCalls() {
-      return keepAliveWithoutCalls;
-    }
-
-    /** @deprecated Please use {@link #setChannelPoolSettings(ChannelPoolSettings)} */
-    @Deprecated
-    public int getPoolSize() {
-      return channelPoolSettings.getInitialChannelCount();
-    }
-
-    /** @deprecated Please use {@link #setChannelPoolSettings(ChannelPoolSettings)} */
-    @Deprecated
-    public Builder setPoolSize(int poolSize) {
-      channelPoolSettings = ChannelPoolSettings.staticallySized(poolSize);
-      return this;
-    }
-
-    /** @deprecated Please use {@link #setChannelPoolSettings(ChannelPoolSettings)} */
-    @Deprecated
-    public Builder setChannelsPerCpu(double multiplier) {
-      return setChannelsPerCpu(multiplier, 100);
-    }
-
-    /** @deprecated Please use {@link #setChannelPoolSettings(ChannelPoolSettings)} */
-    @Deprecated
-    public Builder setChannelsPerCpu(double multiplier, int maxChannels) {
-      Preconditions.checkArgument(multiplier > 0, "multiplier must be positive");
-      Preconditions.checkArgument(maxChannels > 0, "maxChannels must be positive");
-
-      int channelCount = (int) Math.ceil(processorCount * multiplier);
-      if (channelCount > maxChannels) {
-        channelCount = maxChannels;
-      }
-      return setChannelPoolSettings(ChannelPoolSettings.staticallySized(channelCount));
-    }
-
-    @BetaApi("Channel pool sizing api is not yet stable")
-    public Builder setChannelPoolSettings(ChannelPoolSettings settings) {
-      this.channelPoolSettings = settings;
-      return this;
-    }
-
-    public Builder setCredentials(Credentials credentials) {
-      this.credentials = credentials;
-      return this;
-    }
-
-    /**
-     * By setting a channelPrimer, the ChannelPool created by the provider will be refreshing
-     * ChannelPool. channelPrimer will be invoked periodically when the channels are refreshed
-     *
-     * <p>This is public only for technical reasons, for advanced usage.
-     *
-     * @param channelPrimer invoked when the channels are refreshed
-     * @return builder for the provider
-     */
-    @InternalApi("For internal use by google-cloud-java clients only")
-    public Builder setChannelPrimer(ChannelPrimer channelPrimer) {
-      this.channelPrimer = channelPrimer;
-      return this;
-    }
-
-    /** Whether attempt DirectPath. */
-    @InternalApi("For internal use by google-cloud-java clients only")
-    public Builder setAttemptDirectPath(boolean attemptDirectPath) {
-      this.attemptDirectPath = attemptDirectPath;
-      return this;
-    }
-
-    /** Whether allow non-default service account for DirectPath. */
-    @InternalApi("For internal use by google-cloud-java clients only")
-    public Builder setAllowNonDefaultServiceAccount(boolean allowNonDefaultServiceAccount) {
-      this.allowNonDefaultServiceAccount = allowNonDefaultServiceAccount;
-      return this;
-    }
-
-    /**
-     * Sets a service config for direct path. If direct path is not enabled, the provided service
-     * config will be ignored.
-     *
-     * <p>See <a href=
-     * "https://github.com/grpc/grpc-proto/blob/master/grpc/service_config/service_config.proto">
-     * the service config proto definition</a> for more details.
-     */
-    @InternalApi("For internal use by google-cloud-java clients only")
-    public Builder setDirectPathServiceConfig(Map<String, ?> serviceConfig) {
-      Preconditions.checkNotNull(serviceConfig, "serviceConfig");
-      this.directPathServiceConfig = ImmutableMap.copyOf(serviceConfig);
-      return this;
-    }
-
-    public InstantiatingGrpcChannelProvider build() {
-      return new InstantiatingGrpcChannelProvider(this);
-    }
-
-    /**
-     * Add a callback that can intercept channel creation.
-     *
-     * <p>This can be used for advanced configuration like setting the netty event loop. The
-     * callback will be invoked with a fully configured channel builder, which the callback can
-     * augment or replace.
-     */
-    @BetaApi("Surface for advanced channel configuration is not yet stable")
-    public Builder setChannelConfigurator(
-        @Nullable ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator) {
-      this.channelConfigurator = channelConfigurator;
-      return this;
-    }
-
-    @Nullable
-    public ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> getChannelConfigurator() {
-      return channelConfigurator;
-    }
-  }
-
-  private static ImmutableMap<String, ?> getDefaultDirectPathServiceConfig() {
-    // When channel pooling is enabled, force the pick_first grpclb strategy.
-    // This is necessary to avoid the multiplicative effect of creating channel pool with
-    // `poolSize` number of `ManagedChannel`s, each with a `subSetting` number of number of
-    // subchannels.
-    // See the service config proto definition for more details:
-    // https://github.com/grpc/grpc-proto/blob/master/grpc/service_config/service_config.proto
-    ImmutableMap<String, Object> pickFirstStrategy =
-        ImmutableMap.<String, Object>of("pick_first", ImmutableMap.of());
-
-    ImmutableMap<String, Object> childPolicy =
-        ImmutableMap.<String, Object>of("childPolicy", ImmutableList.of(pickFirstStrategy));
-
-    ImmutableMap<String, Object> grpcLbPolicy =
-        ImmutableMap.<String, Object>of("grpclb", childPolicy);
-
-    return ImmutableMap.<String, Object>of("loadBalancingConfig", ImmutableList.of(grpcLbPolicy));
-  }
-
-  private static void validateEndpoint(String endpoint) {
-    int colon = endpoint.lastIndexOf(':');
-    if (colon < 0) {
-      throw new IllegalArgumentException(
-          String.format("invalid endpoint, expecting \"<host>:<port>\""));
-    }
-    Integer.parseInt(endpoint.substring(colon + 1));
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ProtoOperationTransformers.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ProtoOperationTransformers.java
deleted file mode 100644
index e3d990d9e..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ProtoOperationTransformers.java
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.protobuf.Any;
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.Message;
-
-/** Public for technical reasons; intended for use by generated code. */
-public class ProtoOperationTransformers {
-  private ProtoOperationTransformers() {}
-
-  public static class ResponseTransformer<ResponseT extends Message>
-      implements ApiFunction<OperationSnapshot, ResponseT> {
-    private final AnyTransformer<ResponseT> transformer;
-
-    private ResponseTransformer(Class<ResponseT> packedClass) {
-      this.transformer = new AnyTransformer<>(packedClass);
-    }
-
-    @Override
-    public ResponseT apply(OperationSnapshot operationSnapshot) {
-      if (!operationSnapshot.getErrorCode().getCode().equals(Code.OK)) {
-        throw ApiExceptionFactory.createException(
-            "Operation with name \""
-                + operationSnapshot.getName()
-                + "\" failed with status = "
-                + operationSnapshot.getErrorCode()
-                + " and message = "
-                + operationSnapshot.getErrorMessage(),
-            null,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-
-      if (!(operationSnapshot.getResponse() instanceof Any)) {
-        return (ResponseT) operationSnapshot.getResponse();
-      }
-
-      try {
-        return transformer.apply((Any) operationSnapshot.getResponse());
-      } catch (RuntimeException e) {
-        throw ApiExceptionFactory.createException(
-            "Operation with name \""
-                + operationSnapshot.getName()
-                + "\" succeeded, but encountered a problem unpacking it.",
-            e,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-    }
-
-    public static <ResponseT extends Message> ResponseTransformer<ResponseT> create(
-        Class<ResponseT> packedClass) {
-      return new ResponseTransformer<>(packedClass);
-    }
-  }
-
-  public static class MetadataTransformer<MetadataT extends Message>
-      implements ApiFunction<OperationSnapshot, MetadataT> {
-    private final AnyTransformer<MetadataT> transformer;
-
-    private MetadataTransformer(Class<MetadataT> packedClass) {
-      this.transformer = new AnyTransformer<>(packedClass);
-    }
-
-    @Override
-    public MetadataT apply(OperationSnapshot operationSnapshot) {
-      if (!(operationSnapshot.getMetadata() instanceof Any)) {
-        return (MetadataT) operationSnapshot.getMetadata();
-      }
-      try {
-        return transformer.apply((Any) operationSnapshot.getMetadata());
-      } catch (RuntimeException e) {
-        throw ApiExceptionFactory.createException(
-            "Polling operation with name \""
-                + operationSnapshot.getName()
-                + "\" succeeded, but encountered a problem unpacking it.",
-            e,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-    }
-
-    public static <ResponseT extends Message> MetadataTransformer<ResponseT> create(
-        Class<ResponseT> packedClass) {
-      return new MetadataTransformer<>(packedClass);
-    }
-  }
-
-  static class AnyTransformer<PackedT extends Message> implements ApiFunction<Any, PackedT> {
-    private final Class<PackedT> packedClass;
-
-    public AnyTransformer(Class<PackedT> packedClass) {
-      this.packedClass = packedClass;
-    }
-
-    @Override
-    public PackedT apply(Any input) {
-      try {
-        return input == null || packedClass == null ? null : input.unpack(packedClass);
-      } catch (InvalidProtocolBufferException | ClassCastException e) {
-        throw new IllegalStateException(
-            "Failed to unpack object from 'any' field. Expected "
-                + packedClass.getName()
-                + ", found "
-                + input.getTypeUrl());
-      }
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/ResponseMetadataHandler.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/ResponseMetadataHandler.java
deleted file mode 100644
index 4ce195602..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/ResponseMetadataHandler.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import io.grpc.Metadata;
-
-/**
- * An interface to handle metadata returned from an RPC. A ResponseMetadataHandler is used by the
- * GrpcMetadataHandlerInterceptor class to provide custom handling of the returned headers and
- * trailers.
- */
-public interface ResponseMetadataHandler {
-
-  /** Handle the headers returned by an RPC. */
-  void onHeaders(Metadata metadata);
-
-  /** Handle the trailers returned by an RPC. */
-  void onTrailers(Metadata metadata);
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/StreamObserverDelegate.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/StreamObserverDelegate.java
deleted file mode 100644
index 3b66ba1ca..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/StreamObserverDelegate.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.ApiStreamObserver;
-import io.grpc.stub.StreamObserver;
-
-/**
- * A delegate class that transfers calls to the StreamObserver object.
- *
- * <p>Package-private for internal use.
- */
-class StreamObserverDelegate<V> implements ApiStreamObserver<V> {
-
-  private final StreamObserver<V> delegate;
-
-  public StreamObserverDelegate(StreamObserver<V> delegate) {
-    this.delegate = delegate;
-  }
-
-  @Override
-  public void onNext(V v) {
-    delegate.onNext(v);
-  }
-
-  @Override
-  public void onError(Throwable throwable) {
-    delegate.onError(throwable);
-  }
-
-  @Override
-  public void onCompleted() {
-    delegate.onCompleted();
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/GrpcNettyFeature.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/GrpcNettyFeature.java
deleted file mode 100644
index c2cf0a28d..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/GrpcNettyFeature.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.grpc.nativeimage;
-
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerClassForReflection;
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerClassHierarchyForReflection;
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerForReflectiveInstantiation;
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerForUnsafeFieldAccess;
-
-import org.graalvm.nativeimage.hosted.Feature;
-
-/** Configures Native Image settings for the grpc-netty-shaded dependency. */
-final class GrpcNettyFeature implements Feature {
-
-  private static final String GRPC_NETTY_SHADED_CLASS =
-      "io.grpc.netty.shaded.io.grpc.netty.NettyServer";
-
-  private static final String GOOGLE_AUTH_CLASS =
-      "com.google.auth.oauth2.ServiceAccountCredentials";
-
-  private static final String NETTY_SHADED_PACKAGE =
-      "io.grpc.netty.shaded.io.netty.util.internal.shaded.";
-
-  @Override
-  public void beforeAnalysis(BeforeAnalysisAccess access) {
-    loadGoogleAuthClasses(access);
-    loadGrpcNettyClasses(access);
-    loadMiscClasses(access);
-  }
-
-  private static void loadGoogleAuthClasses(BeforeAnalysisAccess access) {
-    // For com.google.auth:google-auth-library-oauth2-http
-    Class<?> authClass = access.findClassByName(GOOGLE_AUTH_CLASS);
-    if (authClass != null) {
-      registerClassHierarchyForReflection(access, GOOGLE_AUTH_CLASS);
-      registerClassHierarchyForReflection(
-          access, "com.google.auth.oauth2.ServiceAccountJwtAccessCredentials");
-    }
-  }
-
-  private static void loadGrpcNettyClasses(BeforeAnalysisAccess access) {
-    // For io.grpc:grpc-netty-shaded
-    Class<?> nettyShadedClass = access.findClassByName(GRPC_NETTY_SHADED_CLASS);
-    if (nettyShadedClass != null) {
-      // Misc. classes used by grpc-netty-shaded
-      registerForReflectiveInstantiation(
-          access, "io.grpc.netty.shaded.io.netty.channel.socket.nio.NioSocketChannel");
-      registerClassForReflection(
-          access, "io.grpc.netty.shaded.io.netty.util.internal.NativeLibraryUtil");
-      registerClassForReflection(access, "io.grpc.netty.shaded.io.netty.util.ReferenceCountUtil");
-      registerClassForReflection(
-          access, "io.grpc.netty.shaded.io.netty.buffer.AbstractByteBufAllocator");
-
-      // Epoll Libraries
-      registerClassForReflection(access, "io.grpc.netty.shaded.io.netty.channel.epoll.Epoll");
-      registerClassForReflection(
-          access, "io.grpc.netty.shaded.io.netty.channel.epoll.EpollChannelOption");
-      registerClassForReflection(
-          access, "io.grpc.netty.shaded.io.netty.channel.epoll.EpollEventLoopGroup");
-      registerForReflectiveInstantiation(
-          access, "io.grpc.netty.shaded.io.netty.channel.epoll.EpollServerSocketChannel");
-      registerForReflectiveInstantiation(
-          access, "io.grpc.netty.shaded.io.netty.channel.epoll.EpollSocketChannel");
-
-      // Unsafe field accesses
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.MpscArrayQueueProducerIndexField",
-          "producerIndex");
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.MpscArrayQueueProducerLimitField",
-          "producerLimit");
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.MpscArrayQueueConsumerIndexField",
-          "consumerIndex");
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.BaseMpscLinkedArrayQueueProducerFields",
-          "producerIndex");
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields",
-          "producerLimit");
-      registerForUnsafeFieldAccess(
-          access,
-          NETTY_SHADED_PACKAGE + "org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields",
-          "consumerIndex");
-    }
-  }
-
-  /** Miscellaneous classes that need to be registered coming from various JARs. */
-  private static void loadMiscClasses(BeforeAnalysisAccess access) {
-    registerClassHierarchyForReflection(access, "com.google.protobuf.DescriptorProtos");
-    registerClassForReflection(access, "com.google.api.FieldBehavior");
-
-    registerForUnsafeFieldAccess(access, "javax.net.ssl.SSLContext", "contextSpi");
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/ProtobufMessageFeature.java b/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/ProtobufMessageFeature.java
deleted file mode 100644
index edea6dee7..000000000
--- a/gax-grpc/src/main/java/com/google/api/gax/grpc/nativeimage/ProtobufMessageFeature.java
+++ /dev/null
@@ -1,117 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.grpc.nativeimage;
-
-import com.google.api.gax.nativeimage.NativeImageUtils;
-import java.lang.reflect.Method;
-import java.util.Arrays;
-import java.util.List;
-import org.graalvm.nativeimage.hosted.Feature;
-import org.graalvm.nativeimage.hosted.RuntimeReflection;
-
-/**
- * A optional feature which registers reflective usages of the GRPC Protobuf libraries.
- *
- * <p>This feature is only needed if you need to access proto objects reflectively (such as
- * printing/logging proto objects).
- */
-final class ProtobufMessageFeature implements Feature {
-
-  // Proto classes to check on the classpath.
-  private static final String PROTO_MESSAGE_CLASS = "com.google.protobuf.GeneratedMessageV3";
-  private static final String PROTO_ENUM_CLASS = "com.google.protobuf.ProtocolMessageEnum";
-  private static final String ENUM_VAL_DESCRIPTOR_CLASS =
-      "com.google.protobuf.Descriptors$EnumValueDescriptor";
-
-  // Prefixes of methods accessed reflectively by
-  // com.google.protobuf.GeneratedMessageV3$ReflectionInvoker
-  private static final List<String> METHOD_ACCESSOR_PREFIXES =
-      Arrays.asList("get", "set", "has", "add", "clear", "newBuilder");
-
-  @Override
-  public void beforeAnalysis(BeforeAnalysisAccess access) {
-    Class<?> protoMessageClass = access.findClassByName(PROTO_MESSAGE_CLASS);
-    if (protoMessageClass != null) {
-      Method internalAccessorMethod =
-          NativeImageUtils.getMethodOrFail(protoMessageClass, "internalGetFieldAccessorTable");
-
-      // Finds every class whose `internalGetFieldAccessorTable()` is reached and registers it.
-      // `internalGetFieldAccessorTable()` is used downstream to access the class reflectively.
-      access.registerMethodOverrideReachabilityHandler(
-          (duringAccess, method) -> {
-            registerFieldAccessors(method.getDeclaringClass());
-            registerFieldAccessors(getBuilderClass(method.getDeclaringClass()));
-          },
-          internalAccessorMethod);
-    }
-
-    Class<?> protoEnumClass = access.findClassByName(PROTO_ENUM_CLASS);
-    if (protoEnumClass != null) {
-      // Finds every reachable proto enum class and registers specific methods for reflection.
-      access.registerSubtypeReachabilityHandler(
-          (duringAccess, subtypeClass) -> {
-            if (!PROTO_ENUM_CLASS.equals(subtypeClass.getName())) {
-              Method method =
-                  NativeImageUtils.getMethodOrFail(
-                      subtypeClass,
-                      "valueOf",
-                      duringAccess.findClassByName(ENUM_VAL_DESCRIPTOR_CLASS));
-              RuntimeReflection.register(method);
-
-              method = NativeImageUtils.getMethodOrFail(subtypeClass, "getValueDescriptor");
-              RuntimeReflection.register(method);
-            }
-          },
-          protoEnumClass);
-    }
-  }
-
-  /** Given a proto class, registers the public accessor methods for the provided proto class. */
-  private static void registerFieldAccessors(Class<?> protoClass) {
-    for (Method method : protoClass.getMethods()) {
-      boolean hasAccessorPrefix =
-          METHOD_ACCESSOR_PREFIXES.stream().anyMatch(prefix -> method.getName().startsWith(prefix));
-      if (hasAccessorPrefix) {
-        RuntimeReflection.register(method);
-      }
-    }
-  }
-
-  /** Given a proto class, returns the Builder nested class. */
-  private static Class<?> getBuilderClass(Class<?> protoClass) {
-    for (Class<?> clazz : protoClass.getClasses()) {
-      if (clazz.getName().endsWith("Builder")) {
-        return clazz;
-      }
-    }
-    return null;
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/OperationsClient.java b/gax-grpc/src/main/java/com/google/longrunning/OperationsClient.java
deleted file mode 100644
index 024950cda..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/OperationsClient.java
+++ /dev/null
@@ -1,666 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.paging.AbstractFixedSizeCollection;
-import com.google.api.gax.paging.AbstractPage;
-import com.google.api.gax.paging.AbstractPagedListResponse;
-import com.google.api.gax.rpc.PageContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.stub.OperationsStub;
-import com.google.longrunning.stub.OperationsStubSettings;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Service Description: Manages long-running operations with an API service.
- *
- * <p>When an API method normally takes long time to complete, it can be designed to return
- * [Operation][google.longrunning.Operation] to the client, and the client can use this interface to
- * receive the real response asynchronously by polling the operation resource, or pass the operation
- * resource to another API (such as Google Cloud Pub/Sub API) to receive the response. Any API
- * service that returns long-running operations should implement the `Operations` interface so
- * developers can have a consistent client experience.
- *
- * <p>This class provides the ability to make remote calls to the backing service through method
- * calls that map to API methods. Sample code to get started:
- *
- * <pre>
- * <code>
- * try (OperationsClient operationsClient = OperationsClient.create()) {
- *   String name = "";
- *   Operation response = operationsClient.getOperation(name);
- * }
- * </code>
- * </pre>
- *
- * <p>Note: close() needs to be called on the operationsClient object to clean up resources such as
- * threads. In the example above, try-with-resources is used, which automatically calls close().
- *
- * <p>The surface of this class includes several types of Java methods for each of the API's
- * methods:
- *
- * <ol>
- *   <li>A "flattened" method. With this type of method, the fields of the request type have been
- *       converted into function parameters. It may be the case that not all fields are available as
- *       parameters, and not every API method will have a flattened method entry point.
- *   <li>A "request object" method. This type of method only takes one parameter, a request object,
- *       which must be constructed before the call. Not every API method will have a request object
- *       method.
- *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
- *       callable object, which can be used to initiate calls to the service.
- * </ol>
- *
- * <p>See the individual methods for example code.
- *
- * <p>Many parameters require resource names to be formatted in a particular way. To assist with
- * these names, this class includes a format method for each type of name, and additionally a parse
- * method to extract the individual identifiers contained within names that are returned.
- *
- * <p>This class can be customized by passing in a custom instance of OperationsSettings to
- * create(). For example:
- *
- * <p>To customize credentials:
- *
- * <pre>
- * <code>
- * OperationsSettings operationsSettings =
- *     OperationsSettings.newBuilder()
- *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
- *         .build();
- * OperationsClient operationsClient =
- *     OperationsClient.create(operationsSettings);
- * </code>
- * </pre>
- */
-public class OperationsClient implements BackgroundResource {
-  private final OperationsSettings settings;
-  private final OperationsStub stub;
-
-  /**
-   * Constructs an instance of OperationsClient, using the given settings. The channels are created
-   * based on the settings passed in, or defaults for any settings that are not set.
-   */
-  public static final OperationsClient create(OperationsSettings settings) throws IOException {
-    return new OperationsClient(settings);
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given stub for making calls. This is for
-   * advanced usage - prefer to use OperationsSettings}.
-   */
-  public static final OperationsClient create(OperationsStub stub) {
-    return new OperationsClient(stub);
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given settings. This is protected so that
-   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
-   */
-  protected OperationsClient(OperationsSettings settings) throws IOException {
-    this.settings = settings;
-    this.stub = ((OperationsStubSettings) settings.getStubSettings()).createStub();
-  }
-
-  protected OperationsClient(OperationsStub stub) {
-    this.settings = null;
-    this.stub = stub;
-  }
-
-  public final OperationsSettings getSettings() {
-    return settings;
-  }
-
-  public OperationsStub getStub() {
-    return stub;
-  }
-
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   Operation response = operationsClient.getOperation(name);
-   * }
-   * </code></pre>
-   *
-   * @param name The name of the operation resource.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final Operation getOperation(String name) {
-
-    GetOperationRequest request = GetOperationRequest.newBuilder().setName(name).build();
-    return getOperation(request);
-  }
-
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   GetOperationRequest request = GetOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   Operation response = operationsClient.getOperation(request);
-   * }
-   * </code></pre>
-   *
-   * @param request the request object containing all of the parameters for the API call
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  private final Operation getOperation(GetOperationRequest request) {
-    return getOperationCallable().call(request);
-  }
-
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   GetOperationRequest request = GetOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   ApiFuture&lt;Operation&gt; future = operationsClient.getOperationCallable().futureCall(request);
-   *   // Do something
-   *   Operation response = future.get();
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    return stub.getOperationCallable();
-  }
-
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding below allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   String filter = "";
-   *   for (Operation element : operationsClient.listOperations(name, filter).iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * </code></pre>
-   *
-   * @param name The name of the operation collection.
-   * @param filter The standard list filter.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final ListOperationsPagedResponse listOperations(String name, String filter) {
-    ListOperationsRequest request =
-        ListOperationsRequest.newBuilder().setName(name).setFilter(filter).build();
-    return listOperations(request);
-  }
-
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding below allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   String filter = "";
-   *   ListOperationsRequest request = ListOperationsRequest.newBuilder()
-   *     .setName(name)
-   *     .setFilter(filter)
-   *     .build();
-   *   for (Operation element : operationsClient.listOperations(request).iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * </code></pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final ListOperationsPagedResponse listOperations(ListOperationsRequest request) {
-    return listOperationsPagedCallable().call(request);
-  }
-
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding below allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   String filter = "";
-   *   ListOperationsRequest request = ListOperationsRequest.newBuilder()
-   *     .setName(name)
-   *     .setFilter(filter)
-   *     .build();
-   *   ApiFuture&lt;ListOperationsPagedResponse&gt; future = operationsClient.listOperationsPagedCallable().futureCall(request);
-   *   // Do something
-   *   for (Operation element : future.get().iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    return stub.listOperationsPagedCallable();
-  }
-
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding below allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   String filter = "";
-   *   ListOperationsRequest request = ListOperationsRequest.newBuilder()
-   *     .setName(name)
-   *     .setFilter(filter)
-   *     .build();
-   *   while (true) {
-   *     ListOperationsResponse response = operationsClient.listOperationsCallable().call(request);
-   *     for (Operation element : response.getOperationsList()) {
-   *       // doThingsWith(element);
-   *     }
-   *     String nextPageToken = response.getNextPageToken();
-   *     if (!Strings.isNullOrEmpty(nextPageToken)) {
-   *       request = request.toBuilder().setPageToken(nextPageToken).build();
-   *     } else {
-   *       break;
-   *     }
-   *   }
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<ListOperationsRequest, ListOperationsResponse>
-      listOperationsCallable() {
-    return stub.listOperationsCallable();
-  }
-
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   operationsClient.cancelOperation(name);
-   * }
-   * </code></pre>
-   *
-   * @param name The name of the operation resource to be cancelled.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void cancelOperation(String name) {
-
-    CancelOperationRequest request = CancelOperationRequest.newBuilder().setName(name).build();
-    cancelOperation(request);
-  }
-
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   CancelOperationRequest request = CancelOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   operationsClient.cancelOperation(request);
-   * }
-   * </code></pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  private final void cancelOperation(CancelOperationRequest request) {
-    cancelOperationCallable().call(request);
-  }
-
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   CancelOperationRequest request = CancelOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   ApiFuture&lt;Void&gt; future = operationsClient.cancelOperationCallable().futureCall(request);
-   *   // Do something
-   *   future.get();
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    return stub.cancelOperationCallable();
-  }
-
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   operationsClient.deleteOperation(name);
-   * }
-   * </code></pre>
-   *
-   * @param name The name of the operation resource to be deleted.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void deleteOperation(String name) {
-
-    DeleteOperationRequest request = DeleteOperationRequest.newBuilder().setName(name).build();
-    deleteOperation(request);
-  }
-
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   DeleteOperationRequest request = DeleteOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   operationsClient.deleteOperation(request);
-   * }
-   * </code></pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  private final void deleteOperation(DeleteOperationRequest request) {
-    deleteOperationCallable().call(request);
-  }
-
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   DeleteOperationRequest request = DeleteOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .build();
-   *   ApiFuture&lt;Void&gt; future = operationsClient.deleteOperationCallable().futureCall(request);
-   *   // Do something
-   *   future.get();
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    return stub.deleteOperationCallable();
-  }
-
-  /**
-   * Waits until the specified long-running operation is done or reaches at most a specified
-   * timeout, returning the latest state. If the operation is already done, the latest state is
-   * immediately returned. If the timeout specified is greater than the default HTTP/RPC timeout,
-   * the HTTP/RPC timeout is used. If the server does not support this method, it returns
-   * `google.rpc.Code.UNIMPLEMENTED`. Note that this method is on a best-effort basis. It may return
-   * the latest state before the specified timeout (including immediately), meaning even an
-   * immediate response is no guarantee that the operation is done.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   WaitOperationRequest request = WaitOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .setTimeout(Duration.ofMillis(100))
-   *     .build();
-   *   Operation response = operationsClient.waitOperation(request);
-   * }
-   * </code></pre>
-   *
-   * @param request the request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final Operation waitOperation(WaitOperationRequest request) {
-    return waitOperationCallable().call(request);
-  }
-
-  /**
-   * Waits until the specified long-running operation is done or reaches at most a specified
-   * timeout, returning the latest state. If the operation is already done, the latest state is
-   * immediately returned. If the timeout specified is greater than the default HTTP/RPC timeout,
-   * the HTTP/RPC timeout is used. If the server does not support this method, it returns
-   * `google.rpc.Code.UNIMPLEMENTED`. Note that this method is on a best-effort basis. It may return
-   * the latest state before the specified timeout (including immediately), meaning even an
-   * immediate response is no guarantee that the operation is done.
-   *
-   * <p>Sample code:
-   *
-   * <pre><code>
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "";
-   *   WaitOperationRequest request = WaitOperationRequest.newBuilder()
-   *     .setName(name)
-   *     .setTimeout(Duration.ofMillis(100))
-   *     .build();
-   *   ApiFuture&lt;Operation&gt; future = operationsClient.waitOperationCallable().futureCall(request);
-   * }
-   * </code></pre>
-   */
-  public final UnaryCallable<WaitOperationRequest, Operation> waitOperationCallable() {
-    return stub.waitOperationCallable();
-  }
-
-  @Override
-  public final void close() {
-    stub.close();
-  }
-
-  @Override
-  public void shutdown() {
-    stub.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return stub.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return stub.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    stub.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return stub.awaitTermination(duration, unit);
-  }
-
-  public static class ListOperationsPagedResponse
-      extends AbstractPagedListResponse<
-          ListOperationsRequest,
-          ListOperationsResponse,
-          Operation,
-          ListOperationsPage,
-          ListOperationsFixedSizeCollection> {
-
-    public static ApiFuture<ListOperationsPagedResponse> createAsync(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ApiFuture<ListOperationsResponse> futureResponse) {
-      ApiFuture<ListOperationsPage> futurePage =
-          ListOperationsPage.createEmptyPage().createPageAsync(context, futureResponse);
-      return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListOperationsPage, ListOperationsPagedResponse>() {
-            @Override
-            public ListOperationsPagedResponse apply(ListOperationsPage input) {
-              return new ListOperationsPagedResponse(input);
-            }
-          },
-          directExecutor());
-    }
-
-    private ListOperationsPagedResponse(ListOperationsPage page) {
-      super(page, ListOperationsFixedSizeCollection.createEmptyCollection());
-    }
-  }
-
-  public static class ListOperationsPage
-      extends AbstractPage<
-          ListOperationsRequest, ListOperationsResponse, Operation, ListOperationsPage> {
-
-    private ListOperationsPage(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ListOperationsResponse response) {
-      super(context, response);
-    }
-
-    private static ListOperationsPage createEmptyPage() {
-      return new ListOperationsPage(null, null);
-    }
-
-    @Override
-    protected ListOperationsPage createPage(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ListOperationsResponse response) {
-      return new ListOperationsPage(context, response);
-    }
-
-    @Override
-    public ApiFuture<ListOperationsPage> createPageAsync(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ApiFuture<ListOperationsResponse> futureResponse) {
-      return super.createPageAsync(context, futureResponse);
-    }
-  }
-
-  public static class ListOperationsFixedSizeCollection
-      extends AbstractFixedSizeCollection<
-          ListOperationsRequest,
-          ListOperationsResponse,
-          Operation,
-          ListOperationsPage,
-          ListOperationsFixedSizeCollection> {
-
-    private ListOperationsFixedSizeCollection(List<ListOperationsPage> pages, int collectionSize) {
-      super(pages, collectionSize);
-    }
-
-    private static ListOperationsFixedSizeCollection createEmptyCollection() {
-      return new ListOperationsFixedSizeCollection(null, 0);
-    }
-
-    @Override
-    protected ListOperationsFixedSizeCollection createCollection(
-        List<ListOperationsPage> pages, int collectionSize) {
-      return new ListOperationsFixedSizeCollection(pages, collectionSize);
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/OperationsSettings.java b/gax-grpc/src/main/java/com/google/longrunning/OperationsSettings.java
deleted file mode 100644
index 22ea7e5a1..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/OperationsSettings.java
+++ /dev/null
@@ -1,182 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.core.GoogleCredentialsProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientSettings;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.longrunning.OperationsClient.ListOperationsPagedResponse;
-import com.google.longrunning.stub.OperationsStubSettings;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-
-/** Settings class to configure an instance of {@link OperationsClient}. */
-public class OperationsSettings extends ClientSettings<OperationsSettings> {
-  /** Returns the object with the settings used for calls to getOperation. */
-  public UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).getOperationSettings();
-  }
-
-  /** Returns the object with the settings used for calls to listOperations. */
-  public PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings() {
-    return ((OperationsStubSettings) getStubSettings()).listOperationsSettings();
-  }
-
-  /** Returns the object with the settings used for calls to cancelOperation. */
-  public UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).cancelOperationSettings();
-  }
-
-  /** Returns the object with the settings used for calls to deleteOperation. */
-  public UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).deleteOperationSettings();
-  }
-
-  /** Returns the object with the settings used for calls to waitOperation. */
-  public UnaryCallSettings<WaitOperationRequest, Operation> waitOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).waitOperationSettings();
-  }
-
-  public static final OperationsSettings create(OperationsStubSettings stub) throws IOException {
-    return new OperationsSettings.Builder(stub.toBuilder()).build();
-  }
-
-  /** Returns a builder for the default ExecutorProvider for this service. */
-  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
-    return OperationsStubSettings.defaultExecutorProviderBuilder();
-  }
-
-  /** Returns a builder for the default credentials for this service. */
-  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return OperationsStubSettings.defaultCredentialsProviderBuilder();
-  }
-
-  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
-    return OperationsStubSettings.defaultApiClientHeaderProviderBuilder();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder() {
-    return Builder.createDefault();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder(ClientContext clientContext) {
-    return new Builder(clientContext);
-  }
-
-  /** Returns a builder containing all the values of this settings class. */
-  @Override
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  protected OperationsSettings(Builder settingsBuilder) throws IOException {
-    super(settingsBuilder);
-  }
-
-  /** Builder for OperationsSettings. */
-  public static class Builder extends ClientSettings.Builder<OperationsSettings, Builder> {
-    protected Builder() throws IOException {
-      this((ClientContext) null);
-    }
-
-    protected Builder(ClientContext clientContext) {
-      super(OperationsStubSettings.newBuilder(clientContext));
-    }
-
-    private static Builder createDefault() {
-      return new Builder(OperationsStubSettings.newBuilder());
-    }
-
-    protected Builder(OperationsSettings settings) {
-      super(settings.getStubSettings().toBuilder());
-    }
-
-    protected Builder(OperationsStubSettings.Builder stubSettings) {
-      super(stubSettings);
-    }
-
-    public OperationsStubSettings.Builder getStubSettingsBuilder() {
-      return ((OperationsStubSettings.Builder) getStubSettings());
-    }
-
-    /**
-     * Applies the given settings updater function to all of the unary API methods in this service.
-     *
-     * <p>Note: This method does not support applying settings to streaming methods.
-     */
-    public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
-      super.applyToAllUnaryMethods(
-          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
-      return this;
-    }
-
-    /** Returns the builder for the settings used for calls to getOperation. */
-    public UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings() {
-      return getStubSettingsBuilder().getOperationSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to listOperations. */
-    public PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings() {
-      return getStubSettingsBuilder().listOperationsSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to cancelOperation. */
-    public UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings() {
-      return getStubSettingsBuilder().cancelOperationSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to deleteOperation. */
-    public UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings() {
-      return getStubSettingsBuilder().deleteOperationSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to deleteOperation. */
-    public UnaryCallSettings.Builder<WaitOperationRequest, Operation> waitOperationSettings() {
-      return getStubSettingsBuilder().waitOperationSettings();
-    }
-
-    @Override
-    public OperationsSettings build() throws IOException {
-      return new OperationsSettings(this);
-    }
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/package-info.java b/gax-grpc/src/main/java/com/google/longrunning/package-info.java
deleted file mode 100644
index 7e509fca0..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/package-info.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-/**
- * A client to Google Long Running Operations API.
- *
- * <p>The interfaces provided are listed below, along with usage samples.
- *
- * <p>================ OperationsClient ================
- *
- * <p>Service Description: Manages long-running operations with an API service.
- *
- * <p>When an API method normally takes long time to complete, it can be designed to return
- * [Operation][google.longrunning.Operation] to the client, and the client can use this interface to
- * receive the real response asynchronously by polling the operation resource, or pass the operation
- * resource to another API (such as Google Cloud Pub/Sub API) to receive the response. Any API
- * service that returns long-running operations should implement the `Operations` interface so
- * developers can have a consistent client experience.
- */
-package com.google.longrunning;
diff --git a/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsCallableFactory.java b/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsCallableFactory.java
deleted file mode 100644
index 8a18008c0..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsCallableFactory.java
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning.stub;
-
-import com.google.api.gax.grpc.GrpcCallSettings;
-import com.google.api.gax.grpc.GrpcCallableFactory;
-import com.google.api.gax.grpc.GrpcStubCallableFactory;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.Operation;
-
-/**
- * gRPC callable factory implementation for Google Long Running Operations API.
- *
- * <p>This class is for advanced usage.
- */
-public class GrpcOperationsCallableFactory implements GrpcStubCallableFactory {
-  @Override
-  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    return GrpcCallableFactory.createUnaryCallable(grpcCallSettings, callSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext) {
-    return GrpcCallableFactory.createPagedCallable(
-        grpcCallSettings, pagedCallSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext) {
-    return GrpcCallableFactory.createBatchingCallable(
-        grpcCallSettings, batchingCallSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          GrpcCallSettings<RequestT, Operation> grpcCallSettings,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          OperationsStub operationsStub) {
-    return GrpcCallableFactory.createOperationCallable(
-        grpcCallSettings, operationCallSettings, clientContext, operationsStub);
-  }
-
-  @Override
-  public <RequestT, ResponseT>
-      BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return GrpcCallableFactory.createBidiStreamingCallable(
-        grpcCallSettings, streamingCallSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          ServerStreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return GrpcCallableFactory.createServerStreamingCallable(
-        grpcCallSettings, streamingCallSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT>
-      ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
-          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return GrpcCallableFactory.createClientStreamingCallable(
-        grpcCallSettings, streamingCallSettings, clientContext);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsStub.java b/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsStub.java
deleted file mode 100644
index c00574e88..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/stub/GrpcOperationsStub.java
+++ /dev/null
@@ -1,307 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning.stub;
-
-import static com.google.longrunning.OperationsClient.ListOperationsPagedResponse;
-
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.BackgroundResourceAggregation;
-import com.google.api.gax.grpc.GrpcCallSettings;
-import com.google.api.gax.grpc.GrpcStubCallableFactory;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.collect.ImmutableMap;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.longrunning.WaitOperationRequest;
-import com.google.protobuf.Empty;
-import io.grpc.MethodDescriptor;
-import io.grpc.protobuf.ProtoUtils;
-import java.io.IOException;
-import java.util.Map;
-import java.util.concurrent.TimeUnit;
-
-/**
- * gRPC stub implementation for Google Long Running Operations API.
- *
- * <p>This class is for advanced usage and reflects the underlying API directly.
- */
-public class GrpcOperationsStub extends OperationsStub {
-
-  private static final MethodDescriptor<GetOperationRequest, Operation>
-      getOperationMethodDescriptor =
-          MethodDescriptor.<GetOperationRequest, Operation>newBuilder()
-              .setType(MethodDescriptor.MethodType.UNARY)
-              .setFullMethodName("google.longrunning.Operations/GetOperation")
-              .setRequestMarshaller(ProtoUtils.marshaller(GetOperationRequest.getDefaultInstance()))
-              .setResponseMarshaller(ProtoUtils.marshaller(Operation.getDefaultInstance()))
-              .build();
-  private static final MethodDescriptor<ListOperationsRequest, ListOperationsResponse>
-      listOperationsMethodDescriptor =
-          MethodDescriptor.<ListOperationsRequest, ListOperationsResponse>newBuilder()
-              .setType(MethodDescriptor.MethodType.UNARY)
-              .setFullMethodName("google.longrunning.Operations/ListOperations")
-              .setRequestMarshaller(
-                  ProtoUtils.marshaller(ListOperationsRequest.getDefaultInstance()))
-              .setResponseMarshaller(
-                  ProtoUtils.marshaller(ListOperationsResponse.getDefaultInstance()))
-              .build();
-  private static final MethodDescriptor<CancelOperationRequest, Empty>
-      cancelOperationMethodDescriptor =
-          MethodDescriptor.<CancelOperationRequest, Empty>newBuilder()
-              .setType(MethodDescriptor.MethodType.UNARY)
-              .setFullMethodName("google.longrunning.Operations/CancelOperation")
-              .setRequestMarshaller(
-                  ProtoUtils.marshaller(CancelOperationRequest.getDefaultInstance()))
-              .setResponseMarshaller(ProtoUtils.marshaller(Empty.getDefaultInstance()))
-              .build();
-  private static final MethodDescriptor<DeleteOperationRequest, Empty>
-      deleteOperationMethodDescriptor =
-          MethodDescriptor.<DeleteOperationRequest, Empty>newBuilder()
-              .setType(MethodDescriptor.MethodType.UNARY)
-              .setFullMethodName("google.longrunning.Operations/DeleteOperation")
-              .setRequestMarshaller(
-                  ProtoUtils.marshaller(DeleteOperationRequest.getDefaultInstance()))
-              .setResponseMarshaller(ProtoUtils.marshaller(Empty.getDefaultInstance()))
-              .build();
-  private static final MethodDescriptor<WaitOperationRequest, Operation>
-      waitOperationMethodDescriptor =
-          MethodDescriptor.<WaitOperationRequest, Operation>newBuilder()
-              .setType(MethodDescriptor.MethodType.UNARY)
-              .setFullMethodName("google.longrunning.Operations/WaitOperation")
-              .setRequestMarshaller(
-                  ProtoUtils.marshaller(WaitOperationRequest.getDefaultInstance()))
-              .setResponseMarshaller(ProtoUtils.marshaller(Operation.getDefaultInstance()))
-              .build();
-
-  private final BackgroundResource backgroundResources;
-
-  private final UnaryCallable<GetOperationRequest, Operation> getOperationCallable;
-  private final UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable;
-  private final UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable;
-  private final UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable;
-  private final UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable;
-  private final UnaryCallable<WaitOperationRequest, Operation> waitOperationCallable;
-
-  private final GrpcStubCallableFactory callableFactory;
-
-  public static final GrpcOperationsStub create(OperationsStubSettings settings)
-      throws IOException {
-    return new GrpcOperationsStub(settings, ClientContext.create(settings));
-  }
-
-  public static final GrpcOperationsStub create(ClientContext clientContext) throws IOException {
-    return new GrpcOperationsStub(OperationsStubSettings.newBuilder().build(), clientContext);
-  }
-
-  public static final GrpcOperationsStub create(
-      ClientContext clientContext, GrpcStubCallableFactory callableFactory) throws IOException {
-    return new GrpcOperationsStub(
-        OperationsStubSettings.newBuilder().build(), clientContext, callableFactory);
-  }
-
-  /**
-   * Constructs an instance of GrpcOperationsStub, using the given settings. This is protected so
-   * that it is easy to make a subclass, but otherwise, the static factory methods should be
-   * preferred.
-   */
-  protected GrpcOperationsStub(OperationsStubSettings settings, ClientContext clientContext)
-      throws IOException {
-    this(settings, clientContext, new GrpcOperationsCallableFactory());
-  }
-
-  /**
-   * Constructs an instance of GrpcOperationsStub, using the given settings. This is protected so
-   * that it is easy to make a subclass, but otherwise, the static factory methods should be
-   * preferred.
-   */
-  protected GrpcOperationsStub(
-      OperationsStubSettings settings,
-      ClientContext clientContext,
-      GrpcStubCallableFactory callableFactory)
-      throws IOException {
-    this.callableFactory = callableFactory;
-
-    GrpcCallSettings<GetOperationRequest, Operation> getOperationTransportSettings =
-        GrpcCallSettings.<GetOperationRequest, Operation>newBuilder()
-            .setMethodDescriptor(getOperationMethodDescriptor)
-            .setParamsExtractor(
-                new RequestParamsExtractor<GetOperationRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetOperationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
-                })
-            .build();
-    GrpcCallSettings<ListOperationsRequest, ListOperationsResponse>
-        listOperationsTransportSettings =
-            GrpcCallSettings.<ListOperationsRequest, ListOperationsResponse>newBuilder()
-                .setMethodDescriptor(listOperationsMethodDescriptor)
-                .setParamsExtractor(
-                    new RequestParamsExtractor<ListOperationsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListOperationsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
-                    })
-                .build();
-    GrpcCallSettings<CancelOperationRequest, Empty> cancelOperationTransportSettings =
-        GrpcCallSettings.<CancelOperationRequest, Empty>newBuilder()
-            .setMethodDescriptor(cancelOperationMethodDescriptor)
-            .setParamsExtractor(
-                new RequestParamsExtractor<CancelOperationRequest>() {
-                  @Override
-                  public Map<String, String> extract(CancelOperationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
-                })
-            .build();
-    GrpcCallSettings<DeleteOperationRequest, Empty> deleteOperationTransportSettings =
-        GrpcCallSettings.<DeleteOperationRequest, Empty>newBuilder()
-            .setMethodDescriptor(deleteOperationMethodDescriptor)
-            .setParamsExtractor(
-                new RequestParamsExtractor<DeleteOperationRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteOperationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
-                })
-            .build();
-    GrpcCallSettings<WaitOperationRequest, Operation> waitOperationTransportSettings =
-        GrpcCallSettings.<WaitOperationRequest, Operation>newBuilder()
-            .setMethodDescriptor(waitOperationMethodDescriptor)
-            .setParamsExtractor(
-                new RequestParamsExtractor<WaitOperationRequest>() {
-                  @Override
-                  public Map<String, String> extract(WaitOperationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
-                })
-            .build();
-
-    this.getOperationCallable =
-        callableFactory.createUnaryCallable(
-            getOperationTransportSettings, settings.getOperationSettings(), clientContext);
-    this.listOperationsCallable =
-        callableFactory.createUnaryCallable(
-            listOperationsTransportSettings, settings.listOperationsSettings(), clientContext);
-    this.listOperationsPagedCallable =
-        callableFactory.createPagedCallable(
-            listOperationsTransportSettings, settings.listOperationsSettings(), clientContext);
-    this.cancelOperationCallable =
-        callableFactory.createUnaryCallable(
-            cancelOperationTransportSettings, settings.cancelOperationSettings(), clientContext);
-    this.deleteOperationCallable =
-        callableFactory.createUnaryCallable(
-            deleteOperationTransportSettings, settings.deleteOperationSettings(), clientContext);
-    this.waitOperationCallable =
-        callableFactory.createUnaryCallable(
-            waitOperationTransportSettings, settings.waitOperationSettings(), clientContext);
-
-    backgroundResources = new BackgroundResourceAggregation(clientContext.getBackgroundResources());
-  }
-
-  @Override
-  public UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    return getOperationCallable;
-  }
-
-  @Override
-  public UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    return listOperationsPagedCallable;
-  }
-
-  @Override
-  public UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable() {
-    return listOperationsCallable;
-  }
-
-  @Override
-  public UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    return cancelOperationCallable;
-  }
-
-  @Override
-  public UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    return deleteOperationCallable;
-  }
-
-  @Override
-  public UnaryCallable<WaitOperationRequest, Operation> waitOperationCallable() {
-    return waitOperationCallable;
-  }
-
-  @Override
-  public final void close() {
-    shutdown();
-  }
-
-  @Override
-  public void shutdown() {
-    backgroundResources.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return backgroundResources.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return backgroundResources.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    backgroundResources.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return backgroundResources.awaitTermination(duration, unit);
-  }
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStub.java b/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStub.java
deleted file mode 100644
index 467572b00..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStub.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning.stub;
-
-import static com.google.longrunning.OperationsClient.ListOperationsPagedResponse;
-
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.longrunning.WaitOperationRequest;
-import com.google.protobuf.Empty;
-
-/**
- * Base stub class for Google Long Running Operations API.
- *
- * <p>This class is for advanced usage and reflects the underlying API directly.
- */
-public abstract class OperationsStub implements BackgroundResource {
-
-  public UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: getOperationCallable()");
-  }
-
-  public UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    throw new UnsupportedOperationException("Not implemented: listOperationsPagedCallable()");
-  }
-
-  public UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable() {
-    throw new UnsupportedOperationException("Not implemented: listOperationsCallable()");
-  }
-
-  public UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: cancelOperationCallable()");
-  }
-
-  public UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: deleteOperationCallable()");
-  }
-
-  public UnaryCallable<WaitOperationRequest, Operation> waitOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: waitOperationCallable()");
-  }
-
-  @Override
-  public abstract void close();
-}
diff --git a/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStubSettings.java b/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStubSettings.java
deleted file mode 100644
index 85da6db5c..000000000
--- a/gax-grpc/src/main/java/com/google/longrunning/stub/OperationsStubSettings.java
+++ /dev/null
@@ -1,385 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning.stub;
-
-import static com.google.longrunning.OperationsClient.ListOperationsPagedResponse;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.core.GaxProperties;
-import com.google.api.gax.core.GoogleCredentialsProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.grpc.GaxGrpcProperties;
-import com.google.api.gax.grpc.GrpcTransportChannel;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.PageContext;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.PagedListDescriptor;
-import com.google.api.gax.rpc.PagedListResponseFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StubSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Lists;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.longrunning.WaitOperationRequest;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import org.threeten.bp.Duration;
-
-/** Settings class to configure an instance of {@link OperationsStub}. */
-public class OperationsStubSettings extends StubSettings<OperationsStubSettings> {
-
-  private final UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings;
-  private final PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings;
-  private final UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings;
-  private final UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings;
-  private final UnaryCallSettings<WaitOperationRequest, Operation> waitOperationSettings;
-
-  /** Returns the object with the settings used for calls to getOperation. */
-  public UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings() {
-    return getOperationSettings;
-  }
-
-  /** Returns the object with the settings used for calls to listOperations. */
-  public PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings() {
-    return listOperationsSettings;
-  }
-
-  /** Returns the object with the settings used for calls to cancelOperation. */
-  public UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings() {
-    return cancelOperationSettings;
-  }
-
-  /** Returns the object with the settings used for calls to deleteOperation. */
-  public UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings() {
-    return deleteOperationSettings;
-  }
-
-  /** Returns the object with the settings used for calls to waitOperation. */
-  public UnaryCallSettings<WaitOperationRequest, Operation> waitOperationSettings() {
-    return waitOperationSettings;
-  }
-
-  public OperationsStub createStub() throws IOException {
-    if (getTransportChannelProvider()
-        .getTransportName()
-        .equals(GrpcTransportChannel.getGrpcTransportName())) {
-      return GrpcOperationsStub.create(this);
-    } else {
-      throw new UnsupportedOperationException(
-          "Transport not supported: " + getTransportChannelProvider().getTransportName());
-    }
-  }
-
-  /** Returns a builder for the default ExecutorProvider for this service. */
-  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
-    return InstantiatingExecutorProvider.newBuilder();
-  }
-
-  /** Returns a builder for the default credentials for this service. */
-  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder();
-  }
-
-  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
-    return ApiClientHeaderProvider.newBuilder()
-        .setGeneratedLibToken(
-            "gapic", GaxProperties.getLibraryVersion(OperationsStubSettings.class))
-        .setTransportToken(
-            GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion());
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder() {
-    return Builder.createDefault();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder(ClientContext clientContext) {
-    return new Builder(clientContext);
-  }
-
-  /** Returns a builder containing all the values of this settings class. */
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  protected OperationsStubSettings(Builder settingsBuilder) throws IOException {
-    super(settingsBuilder);
-
-    getOperationSettings = settingsBuilder.getOperationSettings().build();
-    listOperationsSettings = settingsBuilder.listOperationsSettings().build();
-    cancelOperationSettings = settingsBuilder.cancelOperationSettings().build();
-    deleteOperationSettings = settingsBuilder.deleteOperationSettings().build();
-    waitOperationSettings = settingsBuilder.waitOperationSettings().build();
-  }
-
-  private static final PagedListDescriptor<ListOperationsRequest, ListOperationsResponse, Operation>
-      LIST_OPERATIONS_PAGE_STR_DESC =
-          new PagedListDescriptor<ListOperationsRequest, ListOperationsResponse, Operation>() {
-            @Override
-            public String emptyToken() {
-              return "";
-            }
-
-            @Override
-            public ListOperationsRequest injectToken(ListOperationsRequest payload, String token) {
-              return ListOperationsRequest.newBuilder(payload).setPageToken(token).build();
-            }
-
-            @Override
-            public ListOperationsRequest injectPageSize(
-                ListOperationsRequest payload, int pageSize) {
-              return ListOperationsRequest.newBuilder(payload).setPageSize(pageSize).build();
-            }
-
-            @Override
-            public Integer extractPageSize(ListOperationsRequest payload) {
-              return payload.getPageSize();
-            }
-
-            @Override
-            public String extractNextToken(ListOperationsResponse payload) {
-              return payload.getNextPageToken();
-            }
-
-            @Override
-            public Iterable<Operation> extractResources(ListOperationsResponse payload) {
-              return payload.getOperationsList();
-            }
-          };
-
-  private static final PagedListResponseFactory<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      LIST_OPERATIONS_PAGE_STR_FACT =
-          new PagedListResponseFactory<
-              ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>() {
-            @Override
-            public ApiFuture<ListOperationsPagedResponse> getFuturePagedResponse(
-                UnaryCallable<ListOperationsRequest, ListOperationsResponse> callable,
-                ListOperationsRequest request,
-                ApiCallContext context,
-                ApiFuture<ListOperationsResponse> futureResponse) {
-              PageContext<ListOperationsRequest, ListOperationsResponse, Operation> pageContext =
-                  PageContext.create(callable, LIST_OPERATIONS_PAGE_STR_DESC, request, context);
-              return ListOperationsPagedResponse.createAsync(pageContext, futureResponse);
-            }
-          };
-
-  /** Builder for OperationsStubSettings. */
-  public static class Builder extends StubSettings.Builder<OperationsStubSettings, Builder> {
-    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
-
-    private final UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings;
-    private final PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings;
-    private final UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings;
-    private final UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings;
-    private final UnaryCallSettings.Builder<WaitOperationRequest, Operation> waitOperationSettings;
-
-    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
-        RETRYABLE_CODE_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
-          ImmutableMap.builder();
-      definitions.put(
-          "idempotent",
-          ImmutableSet.copyOf(
-              Lists.<StatusCode.Code>newArrayList(
-                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
-      definitions.put("non_idempotent", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
-      RETRYABLE_CODE_DEFINITIONS = definitions.build();
-    }
-
-    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
-      RetrySettings settings = null;
-      settings =
-          RetrySettings.newBuilder()
-              .setInitialRetryDelay(Duration.ofMillis(100L))
-              .setRetryDelayMultiplier(1.3)
-              .setMaxRetryDelay(Duration.ofMillis(60000L))
-              .setInitialRpcTimeout(Duration.ofMillis(90000L))
-              .setRpcTimeoutMultiplier(1.0)
-              .setMaxRpcTimeout(Duration.ofMillis(90000L))
-              .setTotalTimeout(Duration.ofMillis(600000L))
-              .build();
-      definitions.put("default", settings);
-      RETRY_PARAM_DEFINITIONS = definitions.build();
-    }
-
-    protected Builder() {
-      this((ClientContext) null);
-    }
-
-    protected Builder(ClientContext clientContext) {
-      super(clientContext);
-
-      getOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-
-      listOperationsSettings = PagedCallSettings.newBuilder(LIST_OPERATIONS_PAGE_STR_FACT);
-
-      cancelOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-
-      deleteOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-
-      waitOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-
-      unaryMethodSettingsBuilders =
-          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
-              getOperationSettings,
-              listOperationsSettings,
-              cancelOperationSettings,
-              deleteOperationSettings);
-
-      initDefaults(this);
-    }
-
-    private static Builder createDefault() {
-      Builder builder = new Builder((ClientContext) null);
-      return initDefaults(builder);
-    }
-
-    private static Builder initDefaults(Builder builder) {
-
-      builder
-          .getOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-      builder
-          .listOperationsSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-      builder
-          .cancelOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-      builder
-          .deleteOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-      builder
-          .waitOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-      return builder;
-    }
-
-    protected Builder(OperationsStubSettings settings) {
-      super(settings);
-
-      getOperationSettings = settings.getOperationSettings.toBuilder();
-      listOperationsSettings = settings.listOperationsSettings.toBuilder();
-      cancelOperationSettings = settings.cancelOperationSettings.toBuilder();
-      deleteOperationSettings = settings.deleteOperationSettings.toBuilder();
-      waitOperationSettings = settings.waitOperationSettings.toBuilder();
-
-      unaryMethodSettingsBuilders =
-          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
-              getOperationSettings,
-              listOperationsSettings,
-              cancelOperationSettings,
-              deleteOperationSettings,
-              waitOperationSettings);
-    }
-
-    /**
-     * Applies the given settings updater function to all of the unary API methods in this service.
-     *
-     * <p>Note: This method does not support applying settings to streaming methods.
-     */
-    public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
-      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
-      return this;
-    }
-
-    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
-      return unaryMethodSettingsBuilders;
-    }
-
-    /** Returns the builder for the settings used for calls to getOperation. */
-    public UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings() {
-      return getOperationSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to listOperations. */
-    public PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings() {
-      return listOperationsSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to cancelOperation. */
-    public UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings() {
-      return cancelOperationSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to deleteOperation. */
-    public UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings() {
-      return deleteOperationSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to waitOperation. */
-    public UnaryCallSettings.Builder<WaitOperationRequest, Operation> waitOperationSettings() {
-      return waitOperationSettings;
-    }
-
-    @Override
-    public OperationsStubSettings build() throws IOException {
-      return new OperationsStubSettings(this);
-    }
-  }
-}
diff --git a/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/native-image.properties b/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/native-image.properties
deleted file mode 100644
index f8c0ada53..000000000
--- a/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/native-image.properties
+++ /dev/null
@@ -1,14 +0,0 @@
-Args = --initialize-at-run-time=io.grpc.netty.shaded.io.netty.handler.ssl.OpenSsl,\
-    io.grpc.netty.shaded.io.netty.internal.tcnative.SSL,\
-    io.grpc.netty.shaded.io.netty.internal.tcnative.CertificateVerifier,\
-    io.grpc.netty.shaded.io.netty.internal.tcnative.SSLPrivateKeyMethod,\
-    io.grpc.netty.shaded.io.netty.internal.tcnative.AsyncSSLPrivateKeyMethod,\
-    io.grpc.netty.shaded.io.netty.internal.tcnative.CertificateCompressionAlgo,\
-    io.grpc.netty.shaded.io.grpc.netty,\
-    io.grpc.netty.shaded.io.netty.channel.epoll,\
-    io.grpc.netty.shaded.io.netty.channel.unix,\
-    io.grpc.netty.shaded.io.netty.handler.ssl,\
-    io.grpc.internal.RetriableStream \
-  --features=com.google.api.gax.grpc.nativeimage.ProtobufMessageFeature,\
-  com.google.api.gax.grpc.nativeimage.GrpcNettyFeature \
-  -H:-RunReachabilityHandlersConcurrently
\ No newline at end of file
diff --git a/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/resource-config.json b/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/resource-config.json
deleted file mode 100644
index 08e0ea0c5..000000000
--- a/gax-grpc/src/main/resources/META-INF/native-image/com.google.api/gax-grpc/resource-config.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "resources":[
-    {"pattern":"\\QMETA-INF/native/libio_grpc_netty_shaded_netty_tcnative_linux_x86_64.so\\E"},
-    {"pattern":"\\QMETA-INF/native/libio_grpc_netty_shaded_netty_transport_native_epoll_x86_64.so\\E"},
-    {"pattern":"\\QMETA-INF/services/io.grpc.LoadBalancerProvider\\E"},
-    {"pattern":"\\QMETA-INF/services/io.grpc.ManagedChannelProvider\\E"},
-    {"pattern":"\\QMETA-INF/services/io.grpc.NameResolverProvider\\E"}],
-  "bundles":[]
-}
\ No newline at end of file
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/CallOptionsUtilTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/CallOptionsUtilTest.java
deleted file mode 100644
index 26a6b925f..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/CallOptionsUtilTest.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
-
-import com.google.common.collect.ImmutableMap;
-import io.grpc.CallOptions;
-import io.grpc.Metadata.Key;
-import java.util.Map;
-import org.junit.Test;
-
-public class CallOptionsUtilTest {
-  @Test
-  public void testPutAndGetDynamicHeaderOption() {
-    String encodedRequestParams = "param1=value&param2.param3=value23";
-    CallOptions options =
-        CallOptionsUtil.putRequestParamsDynamicHeaderOption(
-            CallOptions.DEFAULT, encodedRequestParams);
-
-    Map<Key<String>, String> headers = CallOptionsUtil.getDynamicHeadersOption(options);
-
-    assertEquals(
-        ImmutableMap.of(CallOptionsUtil.REQUEST_PARAMS_HEADER_KEY, encodedRequestParams), headers);
-  }
-
-  @Test
-  public void testPutAndGetDynamicHeaderOptionEmpty() {
-    CallOptions options =
-        CallOptionsUtil.putRequestParamsDynamicHeaderOption(CallOptions.DEFAULT, "");
-    assertSame(CallOptions.DEFAULT, options);
-    Map<Key<String>, String> headers = CallOptionsUtil.getDynamicHeadersOption(options);
-    assertTrue(headers.isEmpty());
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void testPutAndGetHeaderOptionNull() {
-    CallOptionsUtil.putRequestParamsDynamicHeaderOption(CallOptions.DEFAULT, null);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/ChannelPoolTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/ChannelPoolTest.java
deleted file mode 100644
index 1bf472653..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/ChannelPoolTest.java
+++ /dev/null
@@ -1,598 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.grpc.testing.FakeChannelFactory;
-import com.google.api.gax.grpc.testing.FakeMethodDescriptor;
-import com.google.api.gax.grpc.testing.FakeServiceGrpc;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ClientCall;
-import io.grpc.ManagedChannel;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-import io.grpc.stub.ClientCalls;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-import org.mockito.stubbing.Answer;
-
-@RunWith(JUnit4.class)
-public class ChannelPoolTest {
-  @Test
-  public void testAuthority() throws IOException {
-    ManagedChannel sub1 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel sub2 = Mockito.mock(ManagedChannel.class);
-
-    Mockito.when(sub1.authority()).thenReturn("myAuth");
-
-    ChannelPool pool =
-        ChannelPool.create(
-            ChannelPoolSettings.staticallySized(2),
-            new FakeChannelFactory(Arrays.asList(sub1, sub2)));
-    assertThat(pool.authority()).isEqualTo("myAuth");
-  }
-
-  @Test
-  public void testRoundRobin() throws IOException {
-    ManagedChannel sub1 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel sub2 = Mockito.mock(ManagedChannel.class);
-
-    Mockito.when(sub1.authority()).thenReturn("myAuth");
-
-    ArrayList<ManagedChannel> channels = Lists.newArrayList(sub1, sub2);
-    ChannelPool pool =
-        ChannelPool.create(
-            ChannelPoolSettings.staticallySized(channels.size()), new FakeChannelFactory(channels));
-
-    verifyTargetChannel(pool, channels, sub1);
-    verifyTargetChannel(pool, channels, sub2);
-    verifyTargetChannel(pool, channels, sub1);
-  }
-
-  private void verifyTargetChannel(
-      ChannelPool pool, List<ManagedChannel> channels, ManagedChannel targetChannel) {
-    MethodDescriptor<Color, Money> methodDescriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-    CallOptions callOptions = CallOptions.DEFAULT;
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> expectedClientCall = Mockito.mock(ClientCall.class);
-
-    channels.forEach(Mockito::reset);
-    Mockito.doReturn(expectedClientCall).when(targetChannel).newCall(methodDescriptor, callOptions);
-
-    ClientCall<Color, Money> actualCall = pool.newCall(methodDescriptor, callOptions);
-    Mockito.verify(targetChannel, Mockito.times(1)).newCall(methodDescriptor, callOptions);
-    actualCall.start(null, null);
-    Mockito.verify(expectedClientCall, Mockito.times(1)).start(Mockito.any(), Mockito.any());
-
-    for (ManagedChannel otherChannel : channels) {
-      if (otherChannel != targetChannel) {
-        Mockito.verify(otherChannel, Mockito.never()).newCall(methodDescriptor, callOptions);
-      }
-    }
-  }
-
-  @Test
-  public void ensureEvenDistribution() throws InterruptedException, IOException {
-    int numChannels = 10;
-    final ManagedChannel[] channels = new ManagedChannel[numChannels];
-    final AtomicInteger[] counts = new AtomicInteger[numChannels];
-
-    final MethodDescriptor<Color, Money> methodDescriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-    final CallOptions callOptions = CallOptions.DEFAULT;
-    @SuppressWarnings("unchecked")
-    final ClientCall<Color, Money> clientCall = Mockito.mock(ClientCall.class);
-
-    for (int i = 0; i < numChannels; i++) {
-      final int index = i;
-
-      counts[i] = new AtomicInteger();
-
-      channels[i] = Mockito.mock(ManagedChannel.class);
-      Mockito.when(channels[i].newCall(methodDescriptor, callOptions))
-          .thenAnswer(
-              (ignored) -> {
-                counts[index].incrementAndGet();
-                return clientCall;
-              });
-    }
-
-    final ChannelPool pool =
-        ChannelPool.create(
-            ChannelPoolSettings.staticallySized(numChannels),
-            new FakeChannelFactory(Arrays.asList(channels)));
-
-    int numThreads = 20;
-    final int numPerThread = 1000;
-
-    ExecutorService executor = Executors.newFixedThreadPool(numThreads);
-    for (int i = 0; i < numThreads; i++) {
-      executor.submit(
-          () -> {
-            for (int j = 0; j < numPerThread; j++) {
-              pool.newCall(methodDescriptor, callOptions);
-            }
-          });
-    }
-    executor.shutdown();
-    boolean shutdown = executor.awaitTermination(1, TimeUnit.MINUTES);
-    assertThat(shutdown).isTrue();
-
-    int expectedCount = (numThreads * numPerThread) / numChannels;
-    for (AtomicInteger count : counts) {
-      assertThat(count.get()).isAnyOf(expectedCount, expectedCount + 1);
-    }
-  }
-
-  // Test channelPrimer is called same number of times as poolSize if executorService is set to null
-  @Test
-  public void channelPrimerShouldCallPoolConstruction() throws IOException {
-    ChannelPrimer mockChannelPrimer = Mockito.mock(ChannelPrimer.class);
-    ManagedChannel channel1 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel channel2 = Mockito.mock(ManagedChannel.class);
-
-    ChannelPool.create(
-        ChannelPoolSettings.staticallySized(2)
-            .toBuilder()
-            .setPreemptiveRefreshEnabled(true)
-            .build(),
-        new FakeChannelFactory(Arrays.asList(channel1, channel2), mockChannelPrimer));
-    Mockito.verify(mockChannelPrimer, Mockito.times(2))
-        .primeChannel(Mockito.any(ManagedChannel.class));
-  }
-
-  // Test channelPrimer is called periodically, if there's an executorService
-  @Test
-  public void channelPrimerIsCalledPeriodically() throws IOException {
-    ChannelPrimer mockChannelPrimer = Mockito.mock(ChannelPrimer.class);
-    ManagedChannel channel1 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel channel2 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel channel3 = Mockito.mock(ManagedChannel.class);
-
-    List<Runnable> channelRefreshers = new ArrayList<>();
-
-    ScheduledExecutorService scheduledExecutorService =
-        Mockito.mock(ScheduledExecutorService.class);
-
-    Answer<?> extractChannelRefresher =
-        invocation -> {
-          channelRefreshers.add(invocation.getArgument(0));
-          return Mockito.mock(ScheduledFuture.class);
-        };
-
-    Mockito.doAnswer(extractChannelRefresher)
-        .when(scheduledExecutorService)
-        .scheduleAtFixedRate(
-            Mockito.any(Runnable.class), Mockito.anyLong(), Mockito.anyLong(), Mockito.any());
-
-    FakeChannelFactory channelFactory =
-        new FakeChannelFactory(Arrays.asList(channel1, channel2, channel3), mockChannelPrimer);
-
-    new ChannelPool(
-        ChannelPoolSettings.staticallySized(1)
-            .toBuilder()
-            .setPreemptiveRefreshEnabled(true)
-            .build(),
-        channelFactory,
-        scheduledExecutorService);
-    // 1 call during the creation
-    Mockito.verify(mockChannelPrimer, Mockito.times(1))
-        .primeChannel(Mockito.any(ManagedChannel.class));
-
-    channelRefreshers.get(0).run();
-    // 1 more call during channel refresh
-    Mockito.verify(mockChannelPrimer, Mockito.times(2))
-        .primeChannel(Mockito.any(ManagedChannel.class));
-
-    channelRefreshers.get(0).run();
-    // 1 more call during channel refresh
-    Mockito.verify(mockChannelPrimer, Mockito.times(3))
-        .primeChannel(Mockito.any(ManagedChannel.class));
-  }
-
-  // ----
-  // call should be allowed to complete and the channel should not be shutdown
-  @Test
-  public void callShouldCompleteAfterCreation() throws IOException {
-    ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
-    ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
-    FakeChannelFactory channelFactory =
-        new FakeChannelFactory(ImmutableList.of(underlyingChannel, replacementChannel));
-    ChannelPool pool = ChannelPool.create(ChannelPoolSettings.staticallySized(1), channelFactory);
-
-    // create a mock call when new call comes to the underlying channel
-    MockClientCall<String, Integer> mockClientCall = new MockClientCall<>(1, Status.OK);
-    MockClientCall<String, Integer> spyClientCall = Mockito.spy(mockClientCall);
-    Mockito.when(
-            underlyingChannel.newCall(
-                Mockito.<MethodDescriptor<String, Integer>>any(), Mockito.any(CallOptions.class)))
-        .thenReturn(spyClientCall);
-
-    Answer<Object> verifyChannelNotShutdown =
-        invocation -> {
-          Mockito.verify(underlyingChannel, Mockito.never()).shutdown();
-          return invocation.callRealMethod();
-        };
-
-    // verify that underlying channel is not shutdown when clientCall is still sending message
-    Mockito.doAnswer(verifyChannelNotShutdown).when(spyClientCall).sendMessage(Mockito.anyString());
-
-    // create a new call on entry
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Integer> listener = Mockito.mock(ClientCall.Listener.class);
-    ClientCall<String, Integer> call =
-        pool.newCall(FakeMethodDescriptor.create(), CallOptions.DEFAULT);
-
-    pool.refresh();
-    // shutdown is not called because there is still an outstanding call, even if it hasn't started
-    Mockito.verify(underlyingChannel, Mockito.after(200).never()).shutdown();
-
-    // start clientCall
-    call.start(listener, new Metadata());
-    // send message and end the call
-    call.sendMessage("message");
-    // shutdown is called because the outstanding call has completed
-    Mockito.verify(underlyingChannel, Mockito.atLeastOnce()).shutdown();
-
-    // Replacement channel shouldn't be touched
-    Mockito.verify(replacementChannel, Mockito.never()).shutdown();
-    Mockito.verify(replacementChannel, Mockito.never()).newCall(Mockito.any(), Mockito.any());
-  }
-
-  // call should be allowed to complete and the channel should not be shutdown
-  @Test
-  public void callShouldCompleteAfterStarted() throws IOException {
-    final ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
-    ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
-
-    FakeChannelFactory channelFactory =
-        new FakeChannelFactory(ImmutableList.of(underlyingChannel, replacementChannel));
-    ChannelPool pool = ChannelPool.create(ChannelPoolSettings.staticallySized(1), channelFactory);
-
-    // create a mock call when new call comes to the underlying channel
-    MockClientCall<String, Integer> mockClientCall = new MockClientCall<>(1, Status.OK);
-    MockClientCall<String, Integer> spyClientCall = Mockito.spy(mockClientCall);
-    Mockito.when(
-            underlyingChannel.newCall(
-                Mockito.<MethodDescriptor<String, Integer>>any(), Mockito.any(CallOptions.class)))
-        .thenReturn(spyClientCall);
-
-    Answer<Object> verifyChannelNotShutdown =
-        invocation -> {
-          Mockito.verify(underlyingChannel, Mockito.never()).shutdown();
-          return invocation.callRealMethod();
-        };
-
-    // verify that underlying channel is not shutdown when clientCall is still sending message
-    Mockito.doAnswer(verifyChannelNotShutdown).when(spyClientCall).sendMessage(Mockito.anyString());
-
-    // create a new call on safeShutdownManagedChannel
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Integer> listener = Mockito.mock(ClientCall.Listener.class);
-    ClientCall<String, Integer> call =
-        pool.newCall(FakeMethodDescriptor.create(), CallOptions.DEFAULT);
-
-    // start clientCall
-    call.start(listener, new Metadata());
-    pool.refresh();
-
-    // shutdown is not called because there is still an outstanding call
-    Mockito.verify(underlyingChannel, Mockito.after(200).never()).shutdown();
-    // send message and end the call
-    call.sendMessage("message");
-    // shutdown is called because the outstanding call has completed
-    Mockito.verify(underlyingChannel, Mockito.atLeastOnce()).shutdown();
-  }
-
-  // Channel should be shutdown after a refresh all the calls have completed
-  @Test
-  public void channelShouldShutdown() throws IOException {
-    ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
-    ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
-
-    FakeChannelFactory channelFactory =
-        new FakeChannelFactory(ImmutableList.of(underlyingChannel, replacementChannel));
-    ChannelPool pool = ChannelPool.create(ChannelPoolSettings.staticallySized(1), channelFactory);
-
-    // create a mock call when new call comes to the underlying channel
-    MockClientCall<String, Integer> mockClientCall = new MockClientCall<>(1, Status.OK);
-    MockClientCall<String, Integer> spyClientCall = Mockito.spy(mockClientCall);
-    Mockito.when(
-            underlyingChannel.newCall(
-                Mockito.<MethodDescriptor<String, Integer>>any(), Mockito.any(CallOptions.class)))
-        .thenReturn(spyClientCall);
-
-    Answer<Object> verifyChannelNotShutdown =
-        invocation -> {
-          Mockito.verify(underlyingChannel, Mockito.never()).shutdown();
-          return invocation.callRealMethod();
-        };
-
-    // verify that underlying channel is not shutdown when clientCall is still sending message
-    Mockito.doAnswer(verifyChannelNotShutdown).when(spyClientCall).sendMessage(Mockito.anyString());
-
-    // create a new call on safeShutdownManagedChannel
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Integer> listener = Mockito.mock(ClientCall.Listener.class);
-    ClientCall<String, Integer> call =
-        pool.newCall(FakeMethodDescriptor.create(), CallOptions.DEFAULT);
-
-    // start clientCall
-    call.start(listener, new Metadata());
-    // send message and end the call
-    call.sendMessage("message");
-    // shutdown is not called because it has not been shutdown yet
-    Mockito.verify(underlyingChannel, Mockito.after(200).never()).shutdown();
-    pool.refresh();
-    // shutdown is called because the outstanding call has completed
-    Mockito.verify(underlyingChannel, Mockito.atLeastOnce()).shutdown();
-  }
-
-  @Test
-  public void channelRefreshShouldSwapChannels() throws IOException {
-    ManagedChannel underlyingChannel1 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel underlyingChannel2 = Mockito.mock(ManagedChannel.class);
-
-    // mock executor service to capture the runnable scheduled, so we can invoke it when we want to
-    ScheduledExecutorService scheduledExecutorService =
-        Mockito.mock(ScheduledExecutorService.class);
-
-    Mockito.doReturn(null)
-        .when(scheduledExecutorService)
-        .schedule(
-            Mockito.any(Runnable.class), Mockito.anyLong(), Mockito.eq(TimeUnit.MILLISECONDS));
-
-    FakeChannelFactory channelFactory =
-        new FakeChannelFactory(ImmutableList.of(underlyingChannel1, underlyingChannel2));
-    ChannelPool pool =
-        new ChannelPool(
-            ChannelPoolSettings.staticallySized(1)
-                .toBuilder()
-                .setPreemptiveRefreshEnabled(true)
-                .build(),
-            channelFactory,
-            scheduledExecutorService);
-    Mockito.reset(underlyingChannel1);
-
-    pool.newCall(FakeMethodDescriptor.<String, Integer>create(), CallOptions.DEFAULT);
-
-    Mockito.verify(underlyingChannel1, Mockito.only())
-        .newCall(Mockito.<MethodDescriptor<String, Integer>>any(), Mockito.any(CallOptions.class));
-
-    // swap channel
-    pool.refresh();
-
-    pool.newCall(FakeMethodDescriptor.<String, Integer>create(), CallOptions.DEFAULT);
-
-    Mockito.verify(underlyingChannel2, Mockito.only())
-        .newCall(Mockito.<MethodDescriptor<String, Integer>>any(), Mockito.any(CallOptions.class));
-  }
-
-  @Test
-  public void channelCountShouldNotChangeWhenOutstandingRpcsAreWithinLimits() throws Exception {
-    ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
-
-    List<ManagedChannel> channels = new ArrayList<>();
-    List<ClientCall<Object, Object>> startedCalls = new ArrayList<>();
-
-    ChannelFactory channelFactory =
-        () -> {
-          ManagedChannel channel = Mockito.mock(ManagedChannel.class);
-          Mockito.when(channel.newCall(Mockito.any(), Mockito.any()))
-              .thenAnswer(
-                  invocation -> {
-                    @SuppressWarnings("unchecked")
-                    ClientCall<Object, Object> clientCall = Mockito.mock(ClientCall.class);
-                    startedCalls.add(clientCall);
-                    return clientCall;
-                  });
-
-          channels.add(channel);
-          return channel;
-        };
-
-    ChannelPool pool =
-        new ChannelPool(
-            ChannelPoolSettings.builder()
-                .setInitialChannelCount(2)
-                .setMinRpcsPerChannel(1)
-                .setMaxRpcsPerChannel(2)
-                .build(),
-            channelFactory,
-            executor);
-    assertThat(pool.entries.get()).hasSize(2);
-
-    // Start the minimum number of
-    for (int i = 0; i < 2; i++) {
-      ClientCalls.futureUnaryCall(
-          pool.newCall(FakeServiceGrpc.METHOD_RECOGNIZE, CallOptions.DEFAULT),
-          Color.getDefaultInstance());
-    }
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(2);
-
-    // Add enough RPCs to be just at the brink of expansion
-    for (int i = startedCalls.size(); i < 4; i++) {
-      ClientCalls.futureUnaryCall(
-          pool.newCall(FakeServiceGrpc.METHOD_RECOGNIZE, CallOptions.DEFAULT),
-          Color.getDefaultInstance());
-    }
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(2);
-
-    // Add another RPC to push expansion
-    pool.newCall(FakeServiceGrpc.METHOD_RECOGNIZE, CallOptions.DEFAULT);
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(4); // += ChannelPool::MAX_RESIZE_DELTA
-    assertThat(startedCalls).hasSize(5);
-
-    // Complete RPCs to the brink of shrinking
-    @SuppressWarnings("unchecked")
-    ArgumentCaptor<ClientCall.Listener<Object>> captor =
-        ArgumentCaptor.forClass(ClientCall.Listener.class);
-    Mockito.verify(startedCalls.remove(0)).start(captor.capture(), Mockito.any());
-    captor.getValue().onClose(Status.ABORTED, new Metadata());
-    // Resize twice: the first round maintains the peak from the last cycle
-    pool.resize();
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(4);
-    assertThat(startedCalls).hasSize(4);
-
-    // Complete another RPC to trigger shrinking
-    Mockito.verify(startedCalls.remove(0)).start(captor.capture(), Mockito.any());
-    captor.getValue().onClose(Status.ABORTED, new Metadata());
-    // Resize twice: the first round maintains the peak from the last cycle
-    pool.resize();
-    pool.resize();
-    assertThat(startedCalls).hasSize(3);
-    // range of channels is [2-3] rounded down average is 2
-    assertThat(pool.entries.get()).hasSize(2);
-  }
-
-  @Test
-  public void removedIdleChannelsAreShutdown() throws Exception {
-    ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
-
-    List<ManagedChannel> channels = new ArrayList<>();
-    List<ClientCall<Object, Object>> startedCalls = new ArrayList<>();
-
-    ChannelFactory channelFactory =
-        () -> {
-          ManagedChannel channel = Mockito.mock(ManagedChannel.class);
-          Mockito.when(channel.newCall(Mockito.any(), Mockito.any()))
-              .thenAnswer(
-                  invocation -> {
-                    @SuppressWarnings("unchecked")
-                    ClientCall<Object, Object> clientCall = Mockito.mock(ClientCall.class);
-                    startedCalls.add(clientCall);
-                    return clientCall;
-                  });
-
-          channels.add(channel);
-          return channel;
-        };
-
-    ChannelPool pool =
-        new ChannelPool(
-            ChannelPoolSettings.builder()
-                .setInitialChannelCount(2)
-                .setMinRpcsPerChannel(1)
-                .setMaxRpcsPerChannel(2)
-                .build(),
-            channelFactory,
-            executor);
-    assertThat(pool.entries.get()).hasSize(2);
-
-    // With no outstanding RPCs, the pool should shrink
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(1);
-    Mockito.verify(channels.get(1), Mockito.times(1)).shutdown();
-  }
-
-  @Test
-  public void removedActiveChannelsAreShutdown() throws Exception {
-    ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
-
-    List<ManagedChannel> channels = new ArrayList<>();
-    List<ClientCall<Object, Object>> startedCalls = new ArrayList<>();
-
-    ChannelFactory channelFactory =
-        () -> {
-          ManagedChannel channel = Mockito.mock(ManagedChannel.class);
-          Mockito.when(channel.newCall(Mockito.any(), Mockito.any()))
-              .thenAnswer(
-                  invocation -> {
-                    @SuppressWarnings("unchecked")
-                    ClientCall<Object, Object> clientCall = Mockito.mock(ClientCall.class);
-                    startedCalls.add(clientCall);
-                    return clientCall;
-                  });
-
-          channels.add(channel);
-          return channel;
-        };
-
-    ChannelPool pool =
-        new ChannelPool(
-            ChannelPoolSettings.builder()
-                .setInitialChannelCount(2)
-                .setMinRpcsPerChannel(1)
-                .setMaxRpcsPerChannel(2)
-                .build(),
-            channelFactory,
-            executor);
-    assertThat(pool.entries.get()).hasSize(2);
-
-    // Start 2 RPCs
-    for (int i = 0; i < 2; i++) {
-      ClientCalls.futureUnaryCall(
-          pool.newCall(FakeServiceGrpc.METHOD_RECOGNIZE, CallOptions.DEFAULT),
-          Color.getDefaultInstance());
-    }
-    // Complete the first one
-    @SuppressWarnings("unchecked")
-    ArgumentCaptor<ClientCall.Listener<Object>> captor =
-        ArgumentCaptor.forClass(ClientCall.Listener.class);
-    Mockito.verify(startedCalls.get(0)).start(captor.capture(), Mockito.any());
-    captor.getValue().onClose(Status.ABORTED, new Metadata());
-
-    // With a single RPC, the pool should shrink
-    pool.resize();
-    pool.resize();
-    assertThat(pool.entries.get()).hasSize(1);
-
-    // While the RPC is outstanding, the channel should still be open
-    Mockito.verify(channels.get(1), Mockito.never()).shutdown();
-
-    // Complete the RPC
-    Mockito.verify(startedCalls.get(1)).start(captor.capture(), Mockito.any());
-    captor.getValue().onClose(Status.ABORTED, new Metadata());
-    // Now the channel should be closed
-    Mockito.verify(channels.get(1), Mockito.times(1)).shutdown();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GaxGrpcPropertiesTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GaxGrpcPropertiesTest.java
deleted file mode 100644
index 417431227..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GaxGrpcPropertiesTest.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-
-import java.util.regex.Pattern;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GaxGrpcPropertiesTest {
-
-  @Test
-  public void testGrpcVersion() {
-    String grpcVersion = GaxGrpcProperties.getGrpcVersion();
-    assertTrue(Pattern.compile("^\\d+\\.\\d+\\.\\d+").matcher(grpcVersion).find());
-  }
-
-  @Test
-  public void testGaxGrpcVersion() {
-    String gaxGrpcVersion = GaxGrpcProperties.getGaxGrpcVersion();
-    assertNotNull(gaxGrpcVersion);
-  }
-
-  @Test
-  public void testDefaultHeaderPattern() {
-    assertTrue(
-        GaxGrpcProperties.getDefaultApiClientHeaderPattern()
-            .matcher("gl-java/1.8_00 gapic/1.2.3-alpha gax/1.5.0 grpc/1.7.0")
-            .matches());
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcApiExceptionFactoryTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcApiExceptionFactoryTest.java
deleted file mode 100644
index bb8febef5..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcApiExceptionFactoryTest.java
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.api.gax.grpc.GrpcApiExceptionFactory.ERROR_DETAIL_KEY;
-
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ErrorDetails;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Any;
-import com.google.protobuf.Duration;
-import com.google.rpc.ErrorInfo;
-import com.google.rpc.RetryInfo;
-import com.google.rpc.Status;
-import io.grpc.Metadata;
-import io.grpc.StatusException;
-import io.grpc.StatusRuntimeException;
-import java.util.Collections;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcApiExceptionFactoryTest {
-
-  private static final ErrorInfo ERROR_INFO =
-      ErrorInfo.newBuilder()
-          .setDomain("googleapis.com")
-          .setReason("SERVICE_DISABLED")
-          .putAllMetadata(Collections.emptyMap())
-          .build();
-
-  private static final RetryInfo RETRY_INFO =
-      RetryInfo.newBuilder().setRetryDelay(Duration.newBuilder().setSeconds(213).build()).build();
-
-  private static final ImmutableList<Any> RAW_ERROR_MESSAGES =
-      ImmutableList.of(Any.pack(ERROR_INFO), Any.pack(RETRY_INFO));
-
-  private static final ErrorDetails ERROR_DETAILS =
-      ErrorDetails.builder().setRawErrorMessages(RAW_ERROR_MESSAGES).build();
-
-  private static final io.grpc.Status GRPC_STATUS = io.grpc.Status.CANCELLED;
-
-  private GrpcApiExceptionFactory factory;
-
-  @Before
-  public void setUp() throws Exception {
-    factory = new GrpcApiExceptionFactory(Collections.emptySet());
-  }
-
-  @Test
-  public void create_shouldCreateApiExceptionWithErrorDetailsForStatusException() {
-    Metadata trailers = new Metadata();
-    Status status = Status.newBuilder().addAllDetails(RAW_ERROR_MESSAGES).build();
-    trailers.put(
-        Metadata.Key.of(ERROR_DETAIL_KEY, Metadata.BINARY_BYTE_MARSHALLER), status.toByteArray());
-    StatusException statusException = new StatusException(GRPC_STATUS, trailers);
-
-    ApiException actual = factory.create(statusException);
-
-    Truth.assertThat(actual.getErrorDetails()).isEqualTo(ERROR_DETAILS);
-  }
-
-  @Test
-  public void create_shouldCreateApiExceptionWithErrorDetailsForStatusRuntimeException() {
-    Metadata trailers = new Metadata();
-    Status status = Status.newBuilder().addAllDetails(RAW_ERROR_MESSAGES).build();
-    trailers.put(
-        Metadata.Key.of(ERROR_DETAIL_KEY, Metadata.BINARY_BYTE_MARSHALLER), status.toByteArray());
-    StatusRuntimeException statusException = new StatusRuntimeException(GRPC_STATUS, trailers);
-
-    ApiException actual = factory.create(statusException);
-
-    Truth.assertThat(actual.getErrorDetails()).isEqualTo(ERROR_DETAILS);
-  }
-
-  @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataIsNull() {
-    StatusRuntimeException statusException = new StatusRuntimeException(GRPC_STATUS, null);
-
-    ApiException actual = factory.create(statusException);
-
-    Truth.assertThat(actual.getErrorDetails()).isNull();
-  }
-
-  @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataDoesNotHaveErrorDetails() {
-    StatusRuntimeException statusException =
-        new StatusRuntimeException(GRPC_STATUS, new Metadata());
-
-    ApiException actual = factory.create(statusException);
-
-    Truth.assertThat(actual.getErrorDetails()).isNull();
-  }
-
-  @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfStatusIsMalformed() {
-    Metadata trailers = new Metadata();
-    Status status = Status.newBuilder().addDetails(Any.pack(ERROR_INFO)).build();
-    byte[] bytes = status.toByteArray();
-    // manually manipulate status bytes array
-    bytes[0] = 123;
-    trailers.put(Metadata.Key.of(ERROR_DETAIL_KEY, Metadata.BINARY_BYTE_MARSHALLER), bytes);
-    StatusRuntimeException statusException = new StatusRuntimeException(GRPC_STATUS, trailers);
-
-    ApiException actual = factory.create(statusException);
-
-    Truth.assertThat(actual.getErrorDetails()).isNull();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallContextTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallContextTest.java
deleted file mode 100644
index 4e563225e..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallContextTest.java
+++ /dev/null
@@ -1,411 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.truth.Truth;
-import io.grpc.CallOptions;
-import io.grpc.ManagedChannel;
-import io.grpc.Metadata.Key;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class GrpcCallContextTest {
-
-  @Test
-  public void testNullToSelfWrongType() {
-    try {
-      GrpcCallContext.createDefault().nullToSelf(FakeCallContext.createDefault());
-      Assert.fail("GrpcCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of GrpcCallContext");
-    }
-  }
-
-  @Test
-  public void testWithCredentials() {
-    Credentials credentials = Mockito.mock(Credentials.class);
-    GrpcCallContext emptyContext = GrpcCallContext.createDefault();
-    assertNull(emptyContext.getCallOptions().getCredentials());
-    GrpcCallContext context = emptyContext.withCredentials(credentials);
-    assertNotNull(context.getCallOptions().getCredentials());
-  }
-
-  @Test
-  public void testWithTransportChannel() {
-    ManagedChannel channel = Mockito.mock(ManagedChannel.class);
-    GrpcCallContext context =
-        GrpcCallContext.createDefault().withTransportChannel(GrpcTransportChannel.create(channel));
-    Truth.assertThat(context.getChannel()).isSameInstanceAs(channel);
-  }
-
-  @Test
-  public void testWithTransportChannelWrongType() {
-    FakeChannel channel = new FakeChannel();
-    try {
-      GrpcCallContext.createDefault().withTransportChannel(FakeTransportChannel.create(channel));
-      Assert.fail("GrpcCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected).hasMessageThat().contains("Expected GrpcTransportChannel");
-    }
-  }
-
-  @Test
-  public void testMergeWrongType() {
-    try {
-      GrpcCallContext.createDefault().merge(FakeCallContext.createDefault());
-      Assert.fail("GrpcCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of " + "GrpcCallContext");
-    }
-  }
-
-  @Test
-  public void testWithRequestParamsDynamicHeaderOption() {
-    String encodedRequestParams = "param1=value&param2.param3=value23";
-    GrpcCallContext context =
-        GrpcCallContext.createDefault().withRequestParamsDynamicHeaderOption(encodedRequestParams);
-
-    Map<Key<String>, String> headers =
-        CallOptionsUtil.getDynamicHeadersOption(context.getCallOptions());
-
-    assertEquals(
-        ImmutableMap.of(CallOptionsUtil.REQUEST_PARAMS_HEADER_KEY, encodedRequestParams), headers);
-  }
-
-  @Test
-  public void testWithTimeout() {
-    assertNull(GrpcCallContext.createDefault().withTimeout(null).getTimeout());
-  }
-
-  @Test
-  public void testWithNegativeTimeout() {
-    assertNull(GrpcCallContext.createDefault().withTimeout(Duration.ofSeconds(-1L)).getTimeout());
-  }
-
-  @Test
-  public void testWithZeroTimeout() {
-    assertNull(GrpcCallContext.createDefault().withTimeout(Duration.ofSeconds(0L)).getTimeout());
-  }
-
-  @Test
-  public void testWithShorterTimeout() {
-    GrpcCallContext ctxWithLongTimeout =
-        GrpcCallContext.createDefault().withTimeout(Duration.ofSeconds(10));
-
-    // Sanity check
-    Truth.assertThat(ctxWithLongTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(10));
-
-    // Shorten the timeout and make sure it changed
-    GrpcCallContext ctxWithShorterTimeout = ctxWithLongTimeout.withTimeout(Duration.ofSeconds(5));
-    Truth.assertThat(ctxWithShorterTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-  }
-
-  @Test
-  public void testWithLongerTimeout() {
-    GrpcCallContext ctxWithShortTimeout =
-        GrpcCallContext.createDefault().withTimeout(Duration.ofSeconds(5));
-
-    // Sanity check
-    Truth.assertThat(ctxWithShortTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-
-    // Try to extend the timeout and verify that it was ignored
-    GrpcCallContext ctxWithUnchangedTimeout =
-        ctxWithShortTimeout.withTimeout(Duration.ofSeconds(10));
-    Truth.assertThat(ctxWithUnchangedTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-  }
-
-  @Test
-  public void testMergeWithNullTimeout() {
-    Duration timeout = Duration.ofSeconds(10);
-    GrpcCallContext baseContext = GrpcCallContext.createDefault().withTimeout(timeout);
-
-    GrpcCallContext defaultOverlay = GrpcCallContext.createDefault();
-    Truth.assertThat(baseContext.merge(defaultOverlay).getTimeout()).isEqualTo(timeout);
-
-    GrpcCallContext explicitNullOverlay = GrpcCallContext.createDefault().withTimeout(null);
-    Truth.assertThat(baseContext.merge(explicitNullOverlay).getTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithTimeout() {
-    Duration timeout = Duration.ofSeconds(19);
-    GrpcCallContext ctx1 = GrpcCallContext.createDefault();
-    GrpcCallContext ctx2 = GrpcCallContext.createDefault().withTimeout(timeout);
-
-    Truth.assertThat(ctx1.merge(ctx2).getTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testWithStreamingWaitTimeout() {
-    Duration timeout = Duration.ofSeconds(15);
-    GrpcCallContext context = GrpcCallContext.createDefault().withStreamWaitTimeout(timeout);
-    Truth.assertThat(context.getStreamWaitTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithNullStreamingWaitTimeout() {
-    Duration timeout = Duration.ofSeconds(10);
-    GrpcCallContext baseContext = GrpcCallContext.createDefault().withStreamWaitTimeout(timeout);
-
-    GrpcCallContext defaultOverlay = GrpcCallContext.createDefault();
-    Truth.assertThat(baseContext.merge(defaultOverlay).getStreamWaitTimeout()).isEqualTo(timeout);
-
-    GrpcCallContext explicitNullOverlay =
-        GrpcCallContext.createDefault().withStreamWaitTimeout(null);
-    Truth.assertThat(baseContext.merge(explicitNullOverlay).getStreamWaitTimeout())
-        .isEqualTo(timeout);
-  }
-
-  @Test
-  public void testWithZeroStreamingWaitTimeout() {
-    Duration timeout = Duration.ZERO;
-    Truth.assertThat(
-            GrpcCallContext.createDefault().withStreamWaitTimeout(timeout).getStreamWaitTimeout())
-        .isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithStreamingWaitTimeout() {
-    Duration timeout = Duration.ofSeconds(19);
-    GrpcCallContext ctx1 = GrpcCallContext.createDefault();
-    GrpcCallContext ctx2 = GrpcCallContext.createDefault().withStreamWaitTimeout(timeout);
-
-    Truth.assertThat(ctx1.merge(ctx2).getStreamWaitTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testWithStreamingIdleTimeout() {
-    Duration timeout = Duration.ofSeconds(15);
-    GrpcCallContext context = GrpcCallContext.createDefault().withStreamIdleTimeout(timeout);
-    Truth.assertThat(context.getStreamIdleTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithNullStreamingIdleTimeout() {
-    Duration timeout = Duration.ofSeconds(10);
-    GrpcCallContext baseContext = GrpcCallContext.createDefault().withStreamIdleTimeout(timeout);
-
-    GrpcCallContext defaultOverlay = GrpcCallContext.createDefault();
-    Truth.assertThat(baseContext.merge(defaultOverlay).getStreamIdleTimeout()).isEqualTo(timeout);
-
-    GrpcCallContext explicitNullOverlay =
-        GrpcCallContext.createDefault().withStreamIdleTimeout(null);
-    Truth.assertThat(baseContext.merge(explicitNullOverlay).getStreamIdleTimeout())
-        .isEqualTo(timeout);
-  }
-
-  @Test
-  public void testWithZeroStreamingIdleTimeout() {
-    Duration timeout = Duration.ZERO;
-    Truth.assertThat(
-            GrpcCallContext.createDefault().withStreamIdleTimeout(timeout).getStreamIdleTimeout())
-        .isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithStreamingIdleTimeout() {
-    Duration timeout = Duration.ofSeconds(19);
-    GrpcCallContext ctx1 = GrpcCallContext.createDefault();
-    GrpcCallContext ctx2 = GrpcCallContext.createDefault().withStreamIdleTimeout(timeout);
-
-    Truth.assertThat(ctx1.merge(ctx2).getStreamIdleTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithCustomCallOptions() {
-    CallOptions.Key<String> key = CallOptions.Key.createWithDefault("somekey", "somedefault");
-    GrpcCallContext ctx1 = GrpcCallContext.createDefault();
-    GrpcCallContext ctx2 =
-        GrpcCallContext.createDefault()
-            .withCallOptions(CallOptions.DEFAULT.withOption(key, "somevalue"));
-
-    GrpcCallContext merged = (GrpcCallContext) ctx1.merge(ctx2);
-    Truth.assertThat(merged.getCallOptions().getOption(key))
-        .isNotEqualTo(ctx1.getCallOptions().getOption(key));
-    Truth.assertThat(merged.getCallOptions().getOption(key))
-        .isEqualTo(ctx2.getCallOptions().getOption(key));
-  }
-
-  @Test
-  public void testWithExtraHeaders() {
-    Map<String, List<String>> extraHeaders =
-        createTestExtraHeaders("key1", "value1", "key1", "value2");
-    GrpcCallContext ctx = GrpcCallContext.createDefault().withExtraHeaders(extraHeaders);
-    Map<String, List<String>> moreExtraHeaders =
-        createTestExtraHeaders("key1", "value2", "key2", "value2");
-    ctx = ctx.withExtraHeaders(moreExtraHeaders);
-    Map<String, List<String>> gotExtraHeaders = ctx.getExtraHeaders();
-    Map<String, List<String>> expectedExtraHeaders =
-        createTestExtraHeaders(
-            "key1", "value1", "key1", "value2", "key1", "value2", "key2", "value2");
-    Truth.assertThat(gotExtraHeaders).containsExactlyEntriesIn(expectedExtraHeaders);
-  }
-
-  @Test
-  public void testMergeWithExtraHeaders() {
-    Map<String, List<String>> extraHeaders1 =
-        createTestExtraHeaders("key1", "value1", "key1", "value2");
-    GrpcCallContext ctx1 = GrpcCallContext.createDefault().withExtraHeaders(extraHeaders1);
-    Map<String, List<String>> extraHeaders2 =
-        createTestExtraHeaders("key1", "value2", "key2", "value2");
-    GrpcCallContext ctx2 = GrpcCallContext.createDefault().withExtraHeaders(extraHeaders2);
-    ApiCallContext mergedApiCallContext = ctx1.merge(ctx2);
-    Truth.assertThat(mergedApiCallContext).isInstanceOf(GrpcCallContext.class);
-    GrpcCallContext mergedGrpcCallContext = (GrpcCallContext) mergedApiCallContext;
-    Map<String, List<String>> gotExtraHeaders = mergedGrpcCallContext.getExtraHeaders();
-    Map<String, List<String>> expectedExtraHeaders =
-        createTestExtraHeaders(
-            "key1", "value1", "key1", "value2", "key1", "value2", "key2", "value2");
-    Truth.assertThat(gotExtraHeaders).containsExactlyEntriesIn(expectedExtraHeaders);
-  }
-
-  @Test
-  public void testMergeWithTracer() {
-    ApiTracer explicitTracer = Mockito.mock(ApiTracer.class);
-    GrpcCallContext ctxWithExplicitTracer =
-        GrpcCallContext.createDefault().withTracer(explicitTracer);
-
-    GrpcCallContext ctxWithDefaultTracer = GrpcCallContext.createDefault();
-    ApiTracer defaultTracer = ctxWithDefaultTracer.getTracer();
-
-    // Explicit tracer overrides the default tracer.
-    Truth.assertThat(ctxWithDefaultTracer.merge(ctxWithExplicitTracer).getTracer())
-        .isSameInstanceAs(explicitTracer);
-
-    // Default tracer does not override an explicit tracer.
-    Truth.assertThat(ctxWithExplicitTracer.merge(ctxWithDefaultTracer).getTracer())
-        .isSameInstanceAs(explicitTracer);
-
-    // Default tracer does not override another default tracer.
-    Truth.assertThat(ctxWithDefaultTracer.merge(GrpcCallContext.createDefault()).getTracer())
-        .isSameInstanceAs(defaultTracer);
-  }
-
-  @Test
-  public void testWithRetrySettings() {
-    RetrySettings retrySettings = Mockito.mock(RetrySettings.class);
-    GrpcCallContext emptyContext = GrpcCallContext.createDefault();
-    assertNull(emptyContext.getRetrySettings());
-    GrpcCallContext context = emptyContext.withRetrySettings(retrySettings);
-    assertNotNull(context.getRetrySettings());
-  }
-
-  @Test
-  public void testWithRetryableCodes() {
-    Set<StatusCode.Code> codes = Collections.singleton(StatusCode.Code.UNAVAILABLE);
-    GrpcCallContext emptyContext = GrpcCallContext.createDefault();
-    assertNull(emptyContext.getRetryableCodes());
-    GrpcCallContext context = emptyContext.withRetryableCodes(codes);
-    assertNotNull(context.getRetryableCodes());
-  }
-
-  @Test
-  public void testWithOptions() {
-    GrpcCallContext emptyCallContext = GrpcCallContext.createDefault();
-    ApiCallContext.Key<String> contextKey1 = ApiCallContext.Key.create("testKey1");
-    ApiCallContext.Key<String> contextKey2 = ApiCallContext.Key.create("testKey2");
-    String testContext1 = "test1";
-    String testContext2 = "test2";
-    String testContextOverwrite = "test1Overwrite";
-    GrpcCallContext context =
-        emptyCallContext
-            .withOption(contextKey1, testContext1)
-            .withOption(contextKey2, testContext2);
-    assertEquals(testContext1, context.getOption(contextKey1));
-    assertEquals(testContext2, context.getOption(contextKey2));
-    GrpcCallContext newContext = context.withOption(contextKey1, testContextOverwrite);
-    assertEquals(testContextOverwrite, newContext.getOption(contextKey1));
-  }
-
-  @Test
-  public void testMergeOptions() {
-    GrpcCallContext emptyCallContext = GrpcCallContext.createDefault();
-    ApiCallContext.Key<String> contextKey1 = ApiCallContext.Key.create("testKey1");
-    ApiCallContext.Key<String> contextKey2 = ApiCallContext.Key.create("testKey2");
-    ApiCallContext.Key<String> contextKey3 = ApiCallContext.Key.create("testKey3");
-    String testContext1 = "test1";
-    String testContext2 = "test2";
-    String testContext3 = "test3";
-    String testContextOverwrite = "test1Overwrite";
-    GrpcCallContext context1 =
-        emptyCallContext
-            .withOption(contextKey1, testContext1)
-            .withOption(contextKey2, testContext2);
-    GrpcCallContext context2 =
-        emptyCallContext
-            .withOption(contextKey1, testContextOverwrite)
-            .withOption(contextKey3, testContext3);
-    ApiCallContext mergedContext = context1.merge(context2);
-    assertEquals(testContextOverwrite, mergedContext.getOption(contextKey1));
-    assertEquals(testContext2, mergedContext.getOption(contextKey2));
-    assertEquals(testContext3, mergedContext.getOption(contextKey3));
-  }
-
-  private static Map<String, List<String>> createTestExtraHeaders(String... keyValues) {
-    Map<String, List<String>> extraHeaders = new HashMap<>();
-    for (int i = 0; i < keyValues.length; i += 2) {
-      String key = keyValues[i];
-      String value = keyValues[i + 1];
-      if (!extraHeaders.containsKey(key)) {
-        extraHeaders.put(key, new ArrayList<String>());
-      }
-      extraHeaders.get(key).add(value);
-    }
-    return extraHeaders;
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallableFactoryTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallableFactoryTest.java
deleted file mode 100644
index 2ebe93b7f..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallableFactoryTest.java
+++ /dev/null
@@ -1,205 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.grpc.testing.FakeServiceGrpc;
-import com.google.api.gax.grpc.testing.FakeServiceImpl;
-import com.google.api.gax.grpc.testing.InProcessServer;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.tracing.SpanName;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ManagedChannel;
-import io.grpc.MethodDescriptor;
-import io.grpc.MethodDescriptor.Marshaller;
-import io.grpc.MethodDescriptor.MethodType;
-import io.grpc.inprocess.InProcessChannelBuilder;
-import java.util.List;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class GrpcCallableFactoryTest {
-  private InProcessServer<FakeServiceImpl> inprocessServer;
-  private ManagedChannel channel;
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() throws Exception {
-    String serverName = "fakeservice";
-    FakeServiceImpl serviceImpl = new FakeServiceImpl();
-    inprocessServer = new InProcessServer<>(serviceImpl, serverName);
-    inprocessServer.start();
-
-    channel = InProcessChannelBuilder.forName(serverName).directExecutor().usePlaintext().build();
-    clientContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(GrpcTransportChannel.create(channel))
-            .setDefaultCallContext(GrpcCallContext.of(channel, CallOptions.DEFAULT))
-            .build();
-  }
-
-  @After
-  public void tearDown() {
-    channel.shutdown();
-    inprocessServer.stop();
-  }
-
-  @Test
-  public void createServerStreamingCallableRetryableExceptions() {
-    GrpcCallSettings<Color, Money> grpcCallSettings =
-        GrpcCallSettings.create(FakeServiceGrpc.METHOD_STREAMING_RECOGNIZE_ERROR);
-
-    // Base case: without config, invalid argument errors are not retryable.
-    ServerStreamingCallSettings<Color, Money> nonRetryableSettings =
-        ServerStreamingCallSettings.<Color, Money>newBuilder()
-            .setRetrySettings(
-                RetrySettings.newBuilder()
-                    .setTotalTimeout(Duration.ofSeconds(1))
-                    .setMaxAttempts(1)
-                    .build())
-            .build();
-
-    ServerStreamingCallable<Color, Money> nonRetryableCallable =
-        GrpcCallableFactory.createServerStreamingCallable(
-            grpcCallSettings, nonRetryableSettings, clientContext);
-
-    Throwable actualError = null;
-    try {
-      nonRetryableCallable
-          .first()
-          .call(Color.getDefaultInstance(), clientContext.getDefaultCallContext());
-    } catch (Throwable e) {
-      actualError = e;
-    }
-    assertThat(actualError).isInstanceOf(InvalidArgumentException.class);
-    assertThat(((InvalidArgumentException) actualError).isRetryable()).isFalse();
-
-    // Actual test: with config, invalid argument errors are retryable.
-    ServerStreamingCallSettings<Color, Money> retryableSettings =
-        ServerStreamingCallSettings.<Color, Money>newBuilder()
-            .setRetryableCodes(Code.INVALID_ARGUMENT)
-            .setRetrySettings(
-                RetrySettings.newBuilder()
-                    .setTotalTimeout(Duration.ofSeconds(1))
-                    .setMaxAttempts(1)
-                    .build())
-            .build();
-
-    ServerStreamingCallable<Color, Money> retryableCallable =
-        GrpcCallableFactory.createServerStreamingCallable(
-            grpcCallSettings, retryableSettings, clientContext);
-
-    Throwable actualError2 = null;
-    try {
-      retryableCallable
-          .first()
-          .call(Color.getDefaultInstance(), clientContext.getDefaultCallContext());
-    } catch (Throwable e) {
-      actualError2 = e;
-    }
-    assertThat(actualError2).isInstanceOf(InvalidArgumentException.class);
-    assertThat(((InvalidArgumentException) actualError2).isRetryable()).isTrue();
-  }
-
-  @Test
-  public void testGetSpanName() {
-    @SuppressWarnings("unchecked")
-    MethodDescriptor<?, ?> descriptor =
-        MethodDescriptor.newBuilder()
-            .setType(MethodType.SERVER_STREAMING)
-            .setFullMethodName("google.bigtable.v2.Bigtable/ReadRows")
-            .setRequestMarshaller(Mockito.mock(Marshaller.class))
-            .setResponseMarshaller(Mockito.mock(Marshaller.class))
-            .build();
-
-    SpanName actualSpanName = GrpcCallableFactory.getSpanName(descriptor);
-    assertThat(actualSpanName).isEqualTo(SpanName.of("Bigtable", "ReadRows"));
-  }
-
-  @Test
-  public void testGetSpanNameUnqualified() {
-    @SuppressWarnings("unchecked")
-    MethodDescriptor<?, ?> descriptor =
-        MethodDescriptor.newBuilder()
-            .setType(MethodType.SERVER_STREAMING)
-            .setFullMethodName("UnqualifiedService/ReadRows")
-            .setRequestMarshaller(Mockito.mock(Marshaller.class))
-            .setResponseMarshaller(Mockito.mock(Marshaller.class))
-            .build();
-
-    SpanName actualSpanName = GrpcCallableFactory.getSpanName(descriptor);
-    assertThat(actualSpanName).isEqualTo(SpanName.of("UnqualifiedService", "ReadRows"));
-  }
-
-  @Test
-  public void testGetSpanNameInvalid() {
-    List<String> invalidNames = ImmutableList.of("BareMethod", "/MethodWithoutService");
-
-    for (String invalidName : invalidNames) {
-      @SuppressWarnings("unchecked")
-      MethodDescriptor<?, ?> descriptor =
-          MethodDescriptor.newBuilder()
-              .setType(MethodType.SERVER_STREAMING)
-              .setFullMethodName(invalidName)
-              .setRequestMarshaller(Mockito.mock(Marshaller.class))
-              .setResponseMarshaller(Mockito.mock(Marshaller.class))
-              .build();
-
-      IllegalArgumentException actualError = null;
-      try {
-        SpanName spanName = GrpcCallableFactory.getSpanName(descriptor);
-        Truth.assertWithMessage(
-                "Invalid method descriptor should not have a valid span name: %s should not generate the spanName: %s",
-                invalidName, spanName)
-            .fail();
-      } catch (IllegalArgumentException e) {
-        actualError = e;
-      }
-
-      assertThat(actualError).isNotNull();
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcClientCallsTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcClientCallsTest.java
deleted file mode 100644
index fcdea5afe..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcClientCallsTest.java
+++ /dev/null
@@ -1,235 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.verify;
-
-import com.google.api.gax.grpc.testing.FakeChannelFactory;
-import com.google.api.gax.grpc.testing.FakeServiceGrpc;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.Deadline;
-import io.grpc.ManagedChannel;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.TimeUnit;
-import org.junit.Test;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-public class GrpcClientCallsTest {
-  @Test
-  public void testAffinity() throws IOException {
-    MethodDescriptor<Color, Money> descriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> clientCall0 = Mockito.mock(ClientCall.class);
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> clientCall1 = Mockito.mock(ClientCall.class);
-
-    ManagedChannel channel0 = Mockito.mock(ManagedChannel.class);
-    ManagedChannel channel1 = Mockito.mock(ManagedChannel.class);
-
-    Mockito.when(channel0.newCall(Mockito.eq(descriptor), Mockito.<CallOptions>any()))
-        .thenReturn(clientCall0);
-    Mockito.when(channel1.newCall(Mockito.eq(descriptor), Mockito.<CallOptions>any()))
-        .thenReturn(clientCall1);
-    Channel pool =
-        ChannelPool.create(
-            ChannelPoolSettings.staticallySized(2),
-            new FakeChannelFactory(Arrays.asList(channel0, channel1)));
-    GrpcCallContext context = GrpcCallContext.createDefault().withChannel(pool);
-
-    ClientCall<Color, Money> gotCallA =
-        GrpcClientCalls.newCall(descriptor, context.withChannelAffinity(0));
-    ClientCall<Color, Money> gotCallB =
-        GrpcClientCalls.newCall(descriptor, context.withChannelAffinity(0));
-    ClientCall<Color, Money> gotCallC =
-        GrpcClientCalls.newCall(descriptor, context.withChannelAffinity(1));
-
-    verify(channel0, Mockito.times(2)).newCall(Mockito.eq(descriptor), Mockito.any());
-    verify(channel1, Mockito.times(1)).newCall(Mockito.eq(descriptor), Mockito.any());
-  }
-
-  @Test
-  public void testExtraHeaders() {
-    Metadata emptyHeaders = new Metadata();
-    final Map<String, List<String>> extraHeaders = new HashMap<>();
-    extraHeaders.put(
-        "header-key-1", ImmutableList.<String>of("header-value-11", "header-value-12"));
-    extraHeaders.put("header-key-2", ImmutableList.<String>of("header-value-21"));
-
-    MethodDescriptor<Color, Money> descriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> mockClientCall = Mockito.mock(ClientCall.class);
-
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Money> mockListener = Mockito.mock(ClientCall.Listener.class);
-
-    Channel mockChannel = Mockito.mock(ManagedChannel.class);
-
-    Mockito.doAnswer(
-            invocation -> {
-              Metadata clientCallHeaders = (Metadata) invocation.getArguments()[1];
-              Metadata.Key<String> key1 =
-                  Metadata.Key.of("header-key-1", Metadata.ASCII_STRING_MARSHALLER);
-              Metadata.Key<String> key2 =
-                  Metadata.Key.of("header-key-2", Metadata.ASCII_STRING_MARSHALLER);
-              assertThat(clientCallHeaders.getAll(key1))
-                  .containsExactly("header-value-11", "header-value-12");
-              assertThat(clientCallHeaders.getAll(key2)).containsExactly("header-value-21");
-              return null;
-            })
-        .when(mockClientCall)
-        .start(Mockito.<ClientCall.Listener<Money>>any(), Mockito.<Metadata>any());
-
-    Mockito.when(mockChannel.newCall(Mockito.eq(descriptor), Mockito.<CallOptions>any()))
-        .thenReturn(mockClientCall);
-
-    GrpcCallContext context =
-        GrpcCallContext.createDefault().withChannel(mockChannel).withExtraHeaders(extraHeaders);
-    GrpcClientCalls.newCall(descriptor, context).start(mockListener, emptyHeaders);
-  }
-
-  @Test
-  public void testTimeoutToDeadlineConversion() {
-    MethodDescriptor<Color, Money> descriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> mockClientCall = Mockito.mock(ClientCall.class);
-
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Money> mockListener = Mockito.mock(ClientCall.Listener.class);
-
-    Channel mockChannel = Mockito.mock(ManagedChannel.class);
-
-    ArgumentCaptor<CallOptions> capturedCallOptions = ArgumentCaptor.forClass(CallOptions.class);
-
-    Mockito.when(mockChannel.newCall(Mockito.eq(descriptor), capturedCallOptions.capture()))
-        .thenReturn(mockClientCall);
-
-    Duration timeout = Duration.ofSeconds(10);
-    Deadline minExpectedDeadline = Deadline.after(timeout.getSeconds(), TimeUnit.SECONDS);
-
-    GrpcCallContext context =
-        GrpcCallContext.createDefault().withChannel(mockChannel).withTimeout(timeout);
-
-    GrpcClientCalls.newCall(descriptor, context).start(mockListener, new Metadata());
-
-    Deadline maxExpectedDeadline = Deadline.after(timeout.getSeconds(), TimeUnit.SECONDS);
-
-    Truth.assertThat(capturedCallOptions.getValue().getDeadline()).isAtLeast(minExpectedDeadline);
-    Truth.assertThat(capturedCallOptions.getValue().getDeadline()).isAtMost(maxExpectedDeadline);
-  }
-
-  @Test
-  public void testTimeoutAfterDeadline() {
-    MethodDescriptor<Color, Money> descriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> mockClientCall = Mockito.mock(ClientCall.class);
-
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Money> mockListener = Mockito.mock(ClientCall.Listener.class);
-
-    Channel mockChannel = Mockito.mock(ManagedChannel.class);
-
-    ArgumentCaptor<CallOptions> capturedCallOptions = ArgumentCaptor.forClass(CallOptions.class);
-
-    Mockito.when(mockChannel.newCall(Mockito.eq(descriptor), capturedCallOptions.capture()))
-        .thenReturn(mockClientCall);
-
-    // Configure a timeout that occurs after the grpc deadline
-    Deadline priorDeadline = Deadline.after(5, TimeUnit.SECONDS);
-    Duration timeout = Duration.ofSeconds(10);
-
-    GrpcCallContext context =
-        GrpcCallContext.createDefault()
-            .withChannel(mockChannel)
-            .withCallOptions(CallOptions.DEFAULT.withDeadline(priorDeadline))
-            .withTimeout(timeout);
-
-    GrpcClientCalls.newCall(descriptor, context).start(mockListener, new Metadata());
-
-    // Verify that the timeout is ignored
-    Truth.assertThat(capturedCallOptions.getValue().getDeadline()).isEqualTo(priorDeadline);
-  }
-
-  @Test
-  public void testTimeoutBeforeDeadline() {
-    MethodDescriptor<Color, Money> descriptor = FakeServiceGrpc.METHOD_RECOGNIZE;
-
-    @SuppressWarnings("unchecked")
-    ClientCall<Color, Money> mockClientCall = Mockito.mock(ClientCall.class);
-
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Money> mockListener = Mockito.mock(ClientCall.Listener.class);
-
-    Channel mockChannel = Mockito.mock(ManagedChannel.class);
-
-    ArgumentCaptor<CallOptions> capturedCallOptions = ArgumentCaptor.forClass(CallOptions.class);
-
-    Mockito.when(mockChannel.newCall(Mockito.eq(descriptor), capturedCallOptions.capture()))
-        .thenReturn(mockClientCall);
-
-    // Configure a timeout that occurs before the grpc deadline
-    Duration timeout = Duration.ofSeconds(5);
-    Deadline subsequentDeadline = Deadline.after(10, TimeUnit.SECONDS);
-    Deadline minExpectedDeadline = Deadline.after(timeout.getSeconds(), TimeUnit.SECONDS);
-
-    GrpcCallContext context =
-        GrpcCallContext.createDefault()
-            .withChannel(mockChannel)
-            .withCallOptions(CallOptions.DEFAULT.withDeadline(subsequentDeadline))
-            .withTimeout(timeout);
-
-    GrpcClientCalls.newCall(descriptor, context).start(mockListener, new Metadata());
-
-    // Verify that the timeout is ignored
-    Deadline maxExpectedDeadline = Deadline.after(timeout.getSeconds(), TimeUnit.SECONDS);
-
-    Truth.assertThat(capturedCallOptions.getValue().getDeadline()).isAtLeast(minExpectedDeadline);
-    Truth.assertThat(capturedCallOptions.getValue().getDeadline()).isAtMost(maxExpectedDeadline);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallableTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallableTest.java
deleted file mode 100644
index e5084b753..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectServerStreamingCallableTest.java
+++ /dev/null
@@ -1,292 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.api.gax.grpc.testing.FakeServiceGrpc.METHOD_SERVER_STREAMING_RECOGNIZE;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.grpc.testing.FakeServiceImpl;
-import com.google.api.gax.grpc.testing.InProcessServer;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStream;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StateCheckingResponseObserver;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StreamController;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ManagedChannel;
-import io.grpc.StatusRuntimeException;
-import io.grpc.inprocess.InProcessChannelBuilder;
-import java.io.IOException;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcDirectServerStreamingCallableTest {
-  private static final Color DEFAULT_REQUEST = Color.newBuilder().setRed(0.5f).build();
-  private static final Color ASYNC_REQUEST = DEFAULT_REQUEST.toBuilder().setGreen(1000).build();
-  private static final Color ERROR_REQUEST = Color.newBuilder().setRed(-1).build();
-  private static final Money DEFAULT_RESPONSE =
-      Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-
-  private InProcessServer<FakeServiceImpl> inprocessServer;
-  private ManagedChannel channel;
-  private ClientContext clientContext;
-  private ServerStreamingCallSettings<Color, Money> streamingCallSettings;
-  private ServerStreamingCallable<Color, Money> streamingCallable;
-
-  @Before
-  public void setUp() throws InstantiationException, IllegalAccessException, IOException {
-    String serverName = "fakeservice";
-    FakeServiceImpl serviceImpl = new FakeServiceImpl();
-    inprocessServer = new InProcessServer<>(serviceImpl, serverName);
-    inprocessServer.start();
-
-    channel = InProcessChannelBuilder.forName(serverName).directExecutor().usePlaintext().build();
-    clientContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(GrpcTransportChannel.create(channel))
-            .setDefaultCallContext(GrpcCallContext.of(channel, CallOptions.DEFAULT))
-            .build();
-    streamingCallSettings = ServerStreamingCallSettings.<Color, Money>newBuilder().build();
-    streamingCallable =
-        GrpcCallableFactory.createServerStreamingCallable(
-            GrpcCallSettings.create(METHOD_SERVER_STREAMING_RECOGNIZE),
-            streamingCallSettings,
-            clientContext);
-  }
-
-  @After
-  public void tearDown() {
-    channel.shutdown();
-    inprocessServer.stop();
-  }
-
-  @Test
-  public void testBadContext() {
-    streamingCallable =
-        GrpcCallableFactory.createServerStreamingCallable(
-            GrpcCallSettings.create(METHOD_SERVER_STREAMING_RECOGNIZE),
-            streamingCallSettings,
-            clientContext
-                .toBuilder()
-                .setDefaultCallContext(FakeCallContext.createDefault())
-                .build());
-
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver observer = new MoneyObserver(true, latch);
-    try {
-      streamingCallable.call(DEFAULT_REQUEST, observer);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of GrpcCallContext");
-    }
-  }
-
-  @Test
-  public void testServerStreamingStart() {
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(moneyObserver.controller).isNotNull();
-  }
-
-  @Test
-  public void testServerStreaming() throws Exception {
-    CountDownLatch latch = new CountDownLatch(2);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(latch.await(20, TimeUnit.SECONDS)).isTrue();
-    Truth.assertThat(moneyObserver.error).isNull();
-    Truth.assertThat(moneyObserver.response).isEqualTo(DEFAULT_RESPONSE);
-  }
-
-  @Test
-  public void testManualFlowControl() throws Exception {
-    CountDownLatch latch = new CountDownLatch(2);
-    MoneyObserver moneyObserver = new MoneyObserver(false, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(latch.await(500, TimeUnit.MILLISECONDS)).isFalse();
-    Truth.assertWithMessage("Received response before requesting it")
-        .that(moneyObserver.response)
-        .isNull();
-
-    moneyObserver.controller.request(1);
-    Truth.assertThat(latch.await(500, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.response).isEqualTo(DEFAULT_RESPONSE);
-    Truth.assertThat(moneyObserver.completed).isTrue();
-  }
-
-  @Test
-  public void testCancelClientCall() throws Exception {
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(false, latch);
-
-    streamingCallable.call(ASYNC_REQUEST, moneyObserver);
-
-    moneyObserver.controller.cancel();
-    moneyObserver.controller.request(1);
-    Truth.assertThat(latch.await(500, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.error).isInstanceOf(CancellationException.class);
-    Truth.assertThat(moneyObserver.error).hasMessageThat().isEqualTo("User cancelled stream");
-  }
-
-  @Test
-  public void testOnResponseError() throws Throwable {
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(ERROR_REQUEST, moneyObserver);
-    Truth.assertThat(latch.await(500, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.error).isInstanceOf(ApiException.class);
-    Truth.assertThat(((ApiException) moneyObserver.error).getStatusCode().getCode())
-        .isEqualTo(StatusCode.Code.INVALID_ARGUMENT);
-    Truth.assertThat(moneyObserver.error)
-        .hasMessageThat()
-        .isEqualTo("io.grpc.StatusRuntimeException: INVALID_ARGUMENT: red must be positive");
-  }
-
-  @Test
-  public void testObserverErrorCancelsCall() throws Throwable {
-    final RuntimeException expectedCause = new RuntimeException("some error");
-    final SettableApiFuture<Throwable> actualErrorF = SettableApiFuture.create();
-
-    ResponseObserver<Money> moneyObserver =
-        new StateCheckingResponseObserver<Money>() {
-          @Override
-          protected void onStartImpl(StreamController controller) {}
-
-          @Override
-          protected void onResponseImpl(Money response) {
-            throw expectedCause;
-          }
-
-          @Override
-          protected void onErrorImpl(Throwable t) {
-            actualErrorF.set(t);
-          }
-
-          @Override
-          protected void onCompleteImpl() {
-            actualErrorF.set(null);
-          }
-        };
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-    Throwable actualError = actualErrorF.get(500, TimeUnit.MILLISECONDS);
-
-    Truth.assertThat(actualError).isInstanceOf(ApiException.class);
-    Truth.assertThat(((ApiException) actualError).getStatusCode().getCode())
-        .isEqualTo(StatusCode.Code.CANCELLED);
-
-    // grpc is responsible for the immediate cancellation
-    Truth.assertThat(actualError.getCause()).isInstanceOf(StatusRuntimeException.class);
-    // and the client error is cause for grpc to cancel it
-    Truth.assertThat(actualError.getCause().getCause()).isSameInstanceAs(expectedCause);
-  }
-
-  @Test
-  public void testBlockingServerStreaming() {
-    Color request = Color.newBuilder().setRed(0.5f).build();
-    ServerStream<Money> response = streamingCallable.call(request);
-    List<Money> responseData = Lists.newArrayList(response);
-
-    Money expected = Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-    Truth.assertThat(responseData).containsExactly(expected);
-  }
-
-  static class MoneyObserver extends StateCheckingResponseObserver<Money> {
-    private final boolean autoFlowControl;
-    private final CountDownLatch latch;
-
-    volatile StreamController controller;
-    volatile Money response;
-    volatile Throwable error;
-    volatile boolean completed;
-
-    MoneyObserver(boolean autoFlowControl, CountDownLatch latch) {
-      this.autoFlowControl = autoFlowControl;
-      this.latch = latch;
-    }
-
-    @Override
-    protected void onStartImpl(StreamController controller) {
-      this.controller = controller;
-      if (!autoFlowControl) {
-        controller.disableAutoInboundFlowControl();
-      }
-    }
-
-    @Override
-    protected void onResponseImpl(Money value) {
-      response = value;
-      latch.countDown();
-    }
-
-    @Override
-    protected void onErrorImpl(Throwable t) {
-      error = t;
-      latch.countDown();
-    }
-
-    @Override
-    protected void onCompleteImpl() {
-      completed = true;
-      latch.countDown();
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectStreamingCallableTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectStreamingCallableTest.java
deleted file mode 100644
index 95d4550b0..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcDirectStreamingCallableTest.java
+++ /dev/null
@@ -1,209 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.api.gax.grpc.testing.FakeServiceGrpc.METHOD_CLIENT_STREAMING_RECOGNIZE;
-import static com.google.api.gax.grpc.testing.FakeServiceGrpc.METHOD_STREAMING_RECOGNIZE;
-import static com.google.api.gax.grpc.testing.FakeServiceGrpc.METHOD_STREAMING_RECOGNIZE_ERROR;
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.grpc.testing.FakeServiceImpl;
-import com.google.api.gax.grpc.testing.InProcessServer;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ManagedChannel;
-import io.grpc.Status;
-import io.grpc.StatusRuntimeException;
-import io.grpc.inprocess.InProcessChannelBuilder;
-import java.io.IOException;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcDirectStreamingCallableTest {
-  private InProcessServer<FakeServiceImpl> inprocessServer;
-  private ManagedChannel channel;
-  private FakeServiceImpl serviceImpl;
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() throws InstantiationException, IllegalAccessException, IOException {
-    String serverName = "fakeservice";
-    serviceImpl = new FakeServiceImpl();
-    inprocessServer = new InProcessServer<>(serviceImpl, serverName);
-    inprocessServer.start();
-    channel = InProcessChannelBuilder.forName(serverName).directExecutor().usePlaintext().build();
-    clientContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(GrpcTransportChannel.create(channel))
-            .setDefaultCallContext(GrpcCallContext.of(channel, CallOptions.DEFAULT))
-            .build();
-  }
-
-  @After
-  public void tearDown() {
-    channel.shutdown();
-    inprocessServer.stop();
-  }
-
-  @Test
-  public void testBidiStreaming() throws Exception {
-    BidiStreamingCallable<Color, Money> streamingCallable =
-        GrpcCallableFactory.createBidiStreamingCallable(
-            GrpcCallSettings.create(METHOD_STREAMING_RECOGNIZE), null, clientContext);
-
-    CountDownLatch latch = new CountDownLatch(1);
-    GrpcDirectServerStreamingCallableTest.MoneyObserver moneyObserver =
-        new GrpcDirectServerStreamingCallableTest.MoneyObserver(true, latch);
-
-    Color request = Color.newBuilder().setRed(0.5f).build();
-    ClientStream<Color> stream = streamingCallable.splitCall(moneyObserver);
-    stream.send(request);
-    stream.closeSend();
-
-    latch.await(20, TimeUnit.SECONDS);
-    assertThat(moneyObserver.error).isNull();
-    Money expected = Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-    assertThat(moneyObserver.response).isEqualTo(expected);
-    assertThat(moneyObserver.completed).isTrue();
-  }
-
-  @Test
-  public void testBidiStreamingServerError() throws Exception {
-    BidiStreamingCallable<Color, Money> streamingCallable =
-        GrpcCallableFactory.createBidiStreamingCallable(
-            GrpcCallSettings.create(METHOD_STREAMING_RECOGNIZE_ERROR), null, clientContext);
-
-    CountDownLatch latch = new CountDownLatch(1);
-    GrpcDirectServerStreamingCallableTest.MoneyObserver moneyObserver =
-        new GrpcDirectServerStreamingCallableTest.MoneyObserver(true, latch);
-
-    Color request = Color.newBuilder().setRed(0.5f).build();
-    ClientStream<Color> stream = streamingCallable.splitCall(moneyObserver);
-    stream.send(request);
-
-    latch.await(20, TimeUnit.SECONDS);
-    assertThat(moneyObserver.error).isNotNull();
-    assertThat(moneyObserver.error).isInstanceOf(ApiException.class);
-    assertThat(moneyObserver.error.getCause()).isInstanceOf(StatusRuntimeException.class);
-    assertThat(((StatusRuntimeException) moneyObserver.error.getCause()).getStatus())
-        .isEqualTo(Status.INVALID_ARGUMENT);
-    assertThat(moneyObserver.response).isNull();
-  }
-
-  @Test
-  public void testBidiStreamingClientError() throws Exception {
-    BidiStreamingCallable<Color, Money> streamingCallable =
-        GrpcCallableFactory.createBidiStreamingCallable(
-            GrpcCallSettings.create(METHOD_STREAMING_RECOGNIZE_ERROR), null, clientContext);
-
-    CountDownLatch latch = new CountDownLatch(1);
-    GrpcDirectServerStreamingCallableTest.MoneyObserver moneyObserver =
-        new GrpcDirectServerStreamingCallableTest.MoneyObserver(true, latch);
-
-    ClientStream<Color> stream = streamingCallable.splitCall(moneyObserver);
-    Throwable clientError = new StatusRuntimeException(Status.CANCELLED);
-    stream.closeSendWithError(clientError);
-
-    latch.await(20, TimeUnit.SECONDS);
-    assertThat(moneyObserver.error).isNotNull();
-    assertThat(moneyObserver.error).isInstanceOf(ApiException.class);
-    assertThat(((ApiException) moneyObserver.error).getStatusCode().getCode())
-        .isEqualTo(Code.CANCELLED);
-    assertThat(moneyObserver.response).isNull();
-
-    // As of gRPC 1.8, when the client closes, the server gRPC issues
-    //   io.grpc.StatusRuntimeException: CANCELLED: cancelled before receiving half close
-    // to the server application, and our error is not propagated.
-    // We don't check the error received by the server; we can't round-trip it.
-  }
-
-  @Test
-  public void testClientStreaming() throws Exception {
-    ClientStreamingCallable<Color, Money> streamingCallable =
-        GrpcCallableFactory.createClientStreamingCallable(
-            GrpcCallSettings.create(METHOD_CLIENT_STREAMING_RECOGNIZE), null, clientContext);
-
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(latch);
-
-    Color request = Color.newBuilder().setRed(0.5f).build();
-    ApiStreamObserver<Color> requestObserver = streamingCallable.clientStreamingCall(moneyObserver);
-    requestObserver.onNext(request);
-    requestObserver.onCompleted();
-
-    latch.await(20, TimeUnit.SECONDS);
-    assertThat(moneyObserver.error).isNull();
-    Money expected = Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-    assertThat(moneyObserver.response).isEqualTo(expected);
-    assertThat(moneyObserver.completed).isTrue();
-  }
-
-  private static class MoneyObserver implements ApiStreamObserver<Money> {
-    volatile Money response;
-    volatile Throwable error;
-    volatile boolean completed;
-    CountDownLatch latch;
-
-    MoneyObserver(CountDownLatch latch) {
-      this.latch = latch;
-    }
-
-    @Override
-    public void onNext(Money value) {
-      response = value;
-      latch.countDown();
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      error = t;
-      latch.countDown();
-    }
-
-    @Override
-    public void onCompleted() {
-      completed = true;
-    }
-  };
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcHeaderInterceptorTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcHeaderInterceptorTest.java
deleted file mode 100644
index cf49ddbcb..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcHeaderInterceptorTest.java
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertEquals;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.same;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.grpc.testing.FakeMethodDescriptor;
-import com.google.common.collect.ImmutableMap;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptors;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import java.util.Map;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.MockitoAnnotations;
-
-/** Tests for {@link GrpcHeaderInterceptor}. */
-@RunWith(JUnit4.class)
-public class GrpcHeaderInterceptorTest {
-
-  @Mock private Channel channel;
-
-  @Mock private ClientCall<String, Integer> call;
-
-  private static final MethodDescriptor<String, Integer> method = FakeMethodDescriptor.create();
-
-  /** Sets up mocks. */
-  @Before
-  public void setUp() {
-    MockitoAnnotations.initMocks(this);
-    when(channel.newCall(Mockito.<MethodDescriptor<String, Integer>>any(), any(CallOptions.class)))
-        .thenReturn(call);
-  }
-
-  @Test
-  public void testInterceptor() {
-    Map<String, String> data = ImmutableMap.of("x-goog-api-client", "abcd", "user-agent", "defg");
-    GrpcHeaderInterceptor interceptor = new GrpcHeaderInterceptor(data);
-    Channel intercepted = ClientInterceptors.intercept(channel, interceptor);
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Integer> listener = mock(ClientCall.Listener.class);
-    ClientCall<String, Integer> interceptedCall = intercepted.newCall(method, CallOptions.DEFAULT);
-    // start() on the intercepted call will eventually reach the call created by the real channel
-    interceptedCall.start(listener, new Metadata());
-    // The headers passed to the real channel call will contain the information inserted by the
-    // interceptor.
-    ArgumentCaptor<Metadata> captor = ArgumentCaptor.forClass(Metadata.class);
-    verify(call).start(same(listener), captor.capture());
-    final Metadata.Key<String> headerKey =
-        Metadata.Key.of("x-goog-api-client", Metadata.ASCII_STRING_MARSHALLER);
-    assertEquals("abcd", captor.getValue().get(headerKey));
-    assertEquals("defg", interceptor.getUserAgentHeader());
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningClientTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningClientTest.java
deleted file mode 100644
index dc3879505..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningClientTest.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.truth.Truth;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.Operation;
-import com.google.longrunning.stub.OperationsStub;
-import com.google.protobuf.Empty;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcLongRunningClientTest {
-
-  @Test
-  public void get() {
-    OperationsStub operationsStub = mock(OperationsStub.class);
-    when(operationsStub.getOperationCallable())
-        .thenReturn(
-            new UnaryCallable<GetOperationRequest, Operation>() {
-              @Override
-              public ApiFuture<Operation> futureCall(
-                  GetOperationRequest request, ApiCallContext context) {
-                if (!request.getName().equals("poseidon")) {
-                  return ApiFutures.immediateFailedFuture(
-                      new IllegalStateException("Unexpected request: " + request));
-                } else {
-                  return ApiFutures.immediateFuture(
-                      Operation.newBuilder().setName("greece").build());
-                }
-              }
-            });
-    LongRunningClient longRunningClient = new GrpcLongRunningClient(operationsStub);
-    Truth.assertThat(longRunningClient.getOperationCallable().call("poseidon").getName())
-        .isEqualTo("greece");
-  }
-
-  @Test
-  public void cancel() {
-    OperationsStub operationsStub = mock(OperationsStub.class);
-    when(operationsStub.cancelOperationCallable())
-        .thenReturn(
-            new UnaryCallable<CancelOperationRequest, Empty>() {
-              @Override
-              public ApiFuture<Empty> futureCall(
-                  CancelOperationRequest request, ApiCallContext context) {
-                if (!request.getName().equals("poseidon")) {
-                  return ApiFutures.immediateFailedFuture(
-                      new IllegalStateException("Unexpected request: " + request));
-                } else {
-                  return ApiFutures.immediateFuture(Empty.getDefaultInstance());
-                }
-              }
-            });
-    LongRunningClient longRunningClient = new GrpcLongRunningClient(operationsStub);
-    Truth.assertThat(longRunningClient.cancelOperationCallable().call("poseidon")).isNull();
-  }
-
-  @Test
-  public void delete() {
-    OperationsStub operationsStub = mock(OperationsStub.class);
-    when(operationsStub.deleteOperationCallable())
-        .thenReturn(
-            new UnaryCallable<DeleteOperationRequest, Empty>() {
-              @Override
-              public ApiFuture<Empty> futureCall(
-                  DeleteOperationRequest request, ApiCallContext context) {
-                if (!request.getName().equals("poseidon")) {
-                  return ApiFutures.immediateFailedFuture(
-                      new IllegalStateException("Unexpected request: " + request));
-                } else {
-                  return ApiFutures.immediateFuture(Empty.getDefaultInstance());
-                }
-              }
-            });
-    LongRunningClient longRunningClient = new GrpcLongRunningClient(operationsStub);
-    Truth.assertThat(longRunningClient.deleteOperationCallable().call("poseidon")).isNull();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningTest.java
deleted file mode 100644
index 7149f23ba..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcLongRunningTest.java
+++ /dev/null
@@ -1,237 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.core.RecordingScheduler;
-import com.google.api.gax.grpc.testing.FakeMethodDescriptor;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.longrunning.OperationTimedPollAlgorithm;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.longrunning.Operation;
-import com.google.longrunning.OperationsSettings;
-import com.google.longrunning.stub.GrpcOperationsStub;
-import com.google.longrunning.stub.OperationsStub;
-import com.google.longrunning.stub.OperationsStubSettings;
-import com.google.protobuf.Any;
-import com.google.protobuf.Message;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ClientCall;
-import io.grpc.ManagedChannel;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-import io.grpc.Status.Code;
-import java.io.IOException;
-import java.util.concurrent.TimeUnit;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class GrpcLongRunningTest {
-
-  private static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(1L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(1L))
-          .setInitialRpcTimeout(Duration.ofMillis(1L))
-          .setMaxAttempts(0)
-          .setJittered(false)
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(1L))
-          .setTotalTimeout(Duration.ofMillis(5L))
-          .build();
-
-  private ManagedChannel channel;
-  private OperationsStub operationsStub;
-  private RecordingScheduler executor;
-  private ClientContext initialContext;
-  private OperationCallSettings<Integer, Color, Money> callSettings;
-
-  private FakeApiClock clock;
-  private OperationTimedPollAlgorithm pollingAlgorithm;
-
-  @Before
-  public void setUp() throws IOException {
-    channel = mock(ManagedChannel.class);
-    TransportChannelProvider operationsChannelProvider = mock(TransportChannelProvider.class);
-    TransportChannel transportChannel =
-        GrpcTransportChannel.newBuilder().setManagedChannel(channel).build();
-    when(operationsChannelProvider.getTransportChannel()).thenReturn(transportChannel);
-
-    clock = new FakeApiClock(0L);
-    executor = RecordingScheduler.create(clock);
-    pollingAlgorithm = OperationTimedPollAlgorithm.create(FAST_RETRY_SETTINGS, clock);
-
-    OperationsSettings.Builder settingsBuilder = OperationsSettings.newBuilder();
-    settingsBuilder
-        .getOperationSettings()
-        .setRetrySettings(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(1).build());
-    OperationsSettings settings =
-        OperationsSettings.newBuilder()
-            .setTransportChannelProvider(operationsChannelProvider)
-            .build();
-    operationsStub =
-        GrpcOperationsStub.create(((OperationsStubSettings) settings.getStubSettings()));
-
-    UnaryCallSettings<Integer, OperationSnapshot> initialCallSettings =
-        UnaryCallSettings.<Integer, OperationSnapshot>newUnaryCallSettingsBuilder()
-            .setRetrySettings(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(1).build())
-            .build();
-
-    callSettings =
-        OperationCallSettings.<Integer, Color, Money>newBuilder()
-            .setInitialCallSettings(initialCallSettings)
-            .setResponseTransformer(
-                ProtoOperationTransformers.ResponseTransformer.create(Color.class))
-            .setMetadataTransformer(
-                ProtoOperationTransformers.MetadataTransformer.create(Money.class))
-            .setPollingAlgorithm(pollingAlgorithm)
-            .build();
-
-    initialContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(
-                GrpcTransportChannel.newBuilder().setManagedChannel(channel).build())
-            .setExecutor(executor)
-            .setDefaultCallContext(GrpcCallContext.of(channel, CallOptions.DEFAULT))
-            .setClock(clock)
-            .build();
-  }
-
-  @Test
-  public void testCall() {
-    Color resp = getColor(1.0f);
-    Money meta = getMoney("UAH");
-    Operation resultOperation = getOperation("testCall", resp, meta, true);
-    mockResponse(channel, Code.OK, resultOperation);
-
-    OperationCallable<Integer, Color, Money> callable =
-        GrpcCallableFactory.createOperationCallable(
-            createGrpcSettings(), callSettings, initialContext, operationsStub);
-
-    Color response = callable.call(2, GrpcCallContext.createDefault());
-    assertThat(response).isEqualTo(resp);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallPollDoneOnFirst() throws Exception {
-    String opName = "testFutureCallPollDoneOnFirst";
-    Color resp = getColor(0.5f);
-    Money meta = getMoney("UAH");
-    Operation initialOperation = getOperation(opName, null, null, false);
-    Operation resultOperation = getOperation(opName, resp, meta, true);
-    mockResponse(channel, Code.OK, initialOperation, resultOperation);
-
-    OperationCallable<Integer, Color, Money> callable =
-        GrpcCallableFactory.createOperationCallable(
-            createGrpcSettings(), callSettings, initialContext, operationsStub);
-
-    OperationFuture<Color, Money> future = callable.futureCall(2);
-
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  private void assertFutureSuccessMetaSuccess(
-      String opName, OperationFuture<Color, Money> future, Color resp, Money meta)
-      throws Exception {
-    assertThat(future.getName()).isEqualTo(opName);
-    assertThat(future.get(3, TimeUnit.SECONDS)).isEqualTo(resp);
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isFalse();
-    assertThat(future.get()).isEqualTo(resp);
-
-    assertThat(future.peekMetadata().get()).isEqualTo(meta);
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isFalse();
-
-    assertThat(future.getMetadata().get()).isEqualTo(meta);
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isFalse();
-  }
-
-  private Color getColor(float blueValue) {
-    return Color.newBuilder().setBlue(blueValue).build();
-  }
-
-  private Money getMoney(String currencyCode) {
-    return Money.newBuilder().setCurrencyCode(currencyCode).build();
-  }
-
-  private Operation getOperation(String name, Message response, Message metadata, boolean done) {
-    Operation.Builder builder = Operation.newBuilder().setName(name).setDone(done);
-    if (response instanceof com.google.rpc.Status) {
-      builder.setError((com.google.rpc.Status) response);
-    } else if (response != null) {
-      builder.setResponse(Any.pack(response));
-    }
-    if (metadata != null) {
-      builder.setMetadata(Any.pack(metadata));
-    }
-    return builder.build();
-  }
-
-  @SuppressWarnings("unchecked")
-  private void mockResponse(ManagedChannel channel, Code statusCode, Object... results) {
-    Status status = statusCode.toStatus();
-    ClientCall<Integer, ?> clientCall = new MockClientCall<>(results[0], status);
-    ClientCall<Integer, ?>[] moreCalls = new ClientCall[results.length - 1];
-    for (int i = 0; i < results.length - 1; i++) {
-      moreCalls[i] = new MockClientCall<>(results[i + 1], status);
-    }
-    when(channel.newCall(any(MethodDescriptor.class), any(CallOptions.class)))
-        .thenReturn(clientCall, moreCalls);
-  }
-
-  private GrpcCallSettings<Integer, Operation> createGrpcSettings() {
-    return GrpcCallSettings.create(FakeMethodDescriptor.<Integer, Operation>create());
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptorTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptorTest.java
deleted file mode 100644
index f8306fddf..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcMetadataHandlerInterceptorTest.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.grpc.testing.FakeMethodDescriptor;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptors;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.Status;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.MockitoAnnotations;
-
-/** Tests for {@link GrpcHeaderInterceptor}. */
-@RunWith(JUnit4.class)
-public class GrpcMetadataHandlerInterceptorTest {
-
-  private static class MutableBoolean {
-    private volatile boolean value = false;
-  }
-
-  @Mock private Channel channel;
-  @Mock private ClientCall<String, Integer> call;
-
-  private static final MethodDescriptor<String, Integer> method = FakeMethodDescriptor.create();
-
-  /** Sets up mocks. */
-  @Before
-  public void setUp() {
-    MockitoAnnotations.initMocks(this);
-    when(channel.newCall(Mockito.<MethodDescriptor<String, Integer>>any(), any(CallOptions.class)))
-        .thenReturn(call);
-  }
-
-  @Test
-  public void testInterceptor() {
-    final MutableBoolean metadataHandlerCalled = new MutableBoolean();
-    final MutableBoolean trailingMetadataHandlerCalled = new MutableBoolean();
-
-    CallOptions callOptions =
-        CallOptionsUtil.putMetadataHandlerOption(
-            CallOptions.DEFAULT,
-            new ResponseMetadataHandler() {
-              @Override
-              public void onHeaders(Metadata metadata) {
-                metadataHandlerCalled.value = true;
-              }
-
-              @Override
-              public void onTrailers(Metadata metadata) {
-                trailingMetadataHandlerCalled.value = true;
-              }
-            });
-
-    GrpcMetadataHandlerInterceptor interceptor = new GrpcMetadataHandlerInterceptor();
-    Channel intercepted = ClientInterceptors.intercept(channel, interceptor);
-    @SuppressWarnings("unchecked")
-    ClientCall.Listener<Integer> listener = mock(ClientCall.Listener.class);
-
-    ClientCall<String, Integer> interceptedCall = intercepted.newCall(method, callOptions);
-
-    // Confirm false
-    assertFalse(metadataHandlerCalled.value);
-    assertFalse(trailingMetadataHandlerCalled.value);
-
-    // start() on the intercepted call will eventually reach the call created by the real channel
-    interceptedCall.start(listener, new Metadata());
-    ArgumentCaptor<ClientCall.Listener> captor = ArgumentCaptor.forClass(ClientCall.Listener.class);
-    ArgumentCaptor<Metadata> metadataCaptor = ArgumentCaptor.forClass(Metadata.class);
-    verify(call).start(captor.capture(), metadataCaptor.capture());
-
-    // Confirm false before calling functions on listener
-    assertFalse(metadataHandlerCalled.value);
-    assertFalse(trailingMetadataHandlerCalled.value);
-
-    captor.getValue().onHeaders(new Metadata());
-
-    // Confirm values after headers but before close
-    assertTrue(metadataHandlerCalled.value);
-    assertFalse(trailingMetadataHandlerCalled.value);
-
-    captor.getValue().onClose(Status.fromCodeValue(0), new Metadata());
-
-    // Confirm values after close
-    assertTrue(metadataHandlerCalled.value);
-    assertTrue(trailingMetadataHandlerCalled.value);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcResponseMetadataTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcResponseMetadataTest.java
deleted file mode 100644
index 80b041a37..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcResponseMetadataTest.java
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.grpc.testing.FakeServiceGrpc;
-import com.google.api.gax.grpc.testing.FakeServiceGrpc.FakeServiceImplBase;
-import com.google.api.gax.grpc.testing.InProcessServer;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.CallOptions;
-import io.grpc.ForwardingServerCall.SimpleForwardingServerCall;
-import io.grpc.ManagedChannel;
-import io.grpc.Metadata;
-import io.grpc.Metadata.Key;
-import io.grpc.ServerCall;
-import io.grpc.ServerCall.Listener;
-import io.grpc.ServerCallHandler;
-import io.grpc.ServerInterceptor;
-import io.grpc.Status;
-import io.grpc.inprocess.InProcessChannelBuilder;
-import io.grpc.stub.StreamObserver;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
-
-@RunWith(JUnit4.class)
-public class GrpcResponseMetadataTest {
-
-  private static final String HEADER_KEY = "inprocessheaderkey";
-  private static final String HEADER_VALUE = "inprocessheadervalue";
-  private static final String TRAILER_KEY = "inprocesstrailerkey";
-  private static final String TRAILER_VALUE = "inprocesstrailervalue";
-
-  private InProcessServer<FakeServiceImplBase> inprocessServer;
-  private ManagedChannel channel;
-  private ClientContext clientContext;
-
-  private Metadata requestHeaders = null;
-
-  @Before
-  public void setUp() throws Exception {
-    String serverName = "fakeservice";
-    FakeServiceImplBase serviceImpl = Mockito.mock(FakeServiceImplBase.class);
-    Mockito.doAnswer(
-            new Answer<Void>() {
-              @Override
-              public Void answer(InvocationOnMock invocation) {
-                Color color = invocation.getArgument(0);
-                StreamObserver<Money> observer = invocation.getArgument(1);
-                observer.onNext(
-                    Money.newBuilder()
-                        .setCurrencyCode("USD")
-                        .setUnits((long) (color.getRed() * 255))
-                        .build());
-                observer.onCompleted();
-                return null;
-              }
-            })
-        .when(serviceImpl)
-        .recognize(Mockito.<Color>any(), Mockito.<StreamObserver<Money>>any());
-    requestHeaders = null;
-    inprocessServer =
-        new InProcessServer<>(
-            serviceImpl,
-            serverName,
-            new ServerInterceptor() {
-              @Override
-              public <ReqT, RespT> Listener<ReqT> interceptCall(
-                  ServerCall<ReqT, RespT> call,
-                  Metadata headers,
-                  ServerCallHandler<ReqT, RespT> next) {
-                requestHeaders = headers;
-                return next.startCall(
-                    new SimpleForwardingServerCall<ReqT, RespT>(call) {
-                      @Override
-                      public void sendHeaders(Metadata responseHeaders) {
-                        responseHeaders.put(
-                            Key.of(HEADER_KEY, Metadata.ASCII_STRING_MARSHALLER), HEADER_VALUE);
-                        super.sendHeaders(responseHeaders);
-                      }
-
-                      @Override
-                      public void close(Status status, Metadata trailers) {
-                        trailers.put(
-                            Key.of(TRAILER_KEY, Metadata.ASCII_STRING_MARSHALLER), TRAILER_VALUE);
-                        super.close(status, trailers);
-                      }
-                    },
-                    headers);
-              }
-            });
-    inprocessServer.start();
-
-    channel =
-        InProcessChannelBuilder.forName(serverName)
-            .directExecutor()
-            .usePlaintext()
-            .intercept(new GrpcMetadataHandlerInterceptor())
-            .build();
-    clientContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(GrpcTransportChannel.create(channel))
-            .setDefaultCallContext(GrpcCallContext.of(channel, CallOptions.DEFAULT))
-            .build();
-  }
-
-  @After
-  public void tearDown() {
-    channel.shutdown();
-    inprocessServer.stop();
-  }
-
-  @Test
-  public void testResponseMetadataUnaryCall() {
-    GrpcCallSettings<Color, Money> grpcCallSettings =
-        GrpcCallSettings.create(FakeServiceGrpc.METHOD_RECOGNIZE);
-
-    UnaryCallSettings<Color, Money> callSettings =
-        UnaryCallSettings.<Color, Money>newUnaryCallSettingsBuilder().build();
-
-    UnaryCallable<Color, Money> callable =
-        GrpcCallableFactory.createUnaryCallable(grpcCallSettings, callSettings, clientContext);
-
-    Assert.assertNull(requestHeaders);
-
-    GrpcResponseMetadata responseMetadata = new GrpcResponseMetadata();
-    callable.call(Color.getDefaultInstance(), responseMetadata.createContextWithHandlers());
-
-    Assert.assertNotNull(requestHeaders);
-
-    Metadata metadata = responseMetadata.getMetadata();
-    Metadata trailingMetadata = responseMetadata.getTrailingMetadata();
-
-    Assert.assertEquals(
-        metadata.get(Key.of(HEADER_KEY, Metadata.ASCII_STRING_MARSHALLER)), HEADER_VALUE);
-    Assert.assertEquals(
-        trailingMetadata.get(Key.of(TRAILER_KEY, Metadata.ASCII_STRING_MARSHALLER)), TRAILER_VALUE);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcStatusCodeTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcStatusCodeTest.java
deleted file mode 100644
index f078a4a92..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcStatusCodeTest.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.gax.rpc.StatusCode;
-import com.google.common.truth.Truth;
-import io.grpc.Status;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcStatusCodeTest {
-  @Test
-  public void testGrpcCodeToStatusCode() {
-    testCodes(StatusCode.Code.OK, Status.Code.OK);
-    testCodes(StatusCode.Code.CANCELLED, Status.Code.CANCELLED);
-    testCodes(StatusCode.Code.UNKNOWN, Status.Code.UNKNOWN);
-    testCodes(StatusCode.Code.INVALID_ARGUMENT, Status.Code.INVALID_ARGUMENT);
-    testCodes(StatusCode.Code.DEADLINE_EXCEEDED, Status.Code.DEADLINE_EXCEEDED);
-    testCodes(StatusCode.Code.NOT_FOUND, Status.Code.NOT_FOUND);
-    testCodes(StatusCode.Code.ALREADY_EXISTS, Status.Code.ALREADY_EXISTS);
-    testCodes(StatusCode.Code.PERMISSION_DENIED, Status.Code.PERMISSION_DENIED);
-    testCodes(StatusCode.Code.RESOURCE_EXHAUSTED, Status.Code.RESOURCE_EXHAUSTED);
-    testCodes(StatusCode.Code.FAILED_PRECONDITION, Status.Code.FAILED_PRECONDITION);
-    testCodes(StatusCode.Code.ABORTED, Status.Code.ABORTED);
-    testCodes(StatusCode.Code.OUT_OF_RANGE, Status.Code.OUT_OF_RANGE);
-    testCodes(StatusCode.Code.UNIMPLEMENTED, Status.Code.UNIMPLEMENTED);
-    testCodes(StatusCode.Code.INTERNAL, Status.Code.INTERNAL);
-    testCodes(StatusCode.Code.UNAVAILABLE, Status.Code.UNAVAILABLE);
-    testCodes(StatusCode.Code.DATA_LOSS, Status.Code.DATA_LOSS);
-    testCodes(StatusCode.Code.UNAUTHENTICATED, Status.Code.UNAUTHENTICATED);
-  }
-
-  private void testCodes(StatusCode.Code gaxCode, Status.Code grpcCode) {
-    Truth.assertThat(GrpcStatusCode.grpcCodeToStatusCode(grpcCode)).isEqualTo(gaxCode);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcTransportDescriptorTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcTransportDescriptorTest.java
deleted file mode 100644
index 456d4e73b..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcTransportDescriptorTest.java
+++ /dev/null
@@ -1,188 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.fail;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.DataLossException;
-import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.UnavailableException;
-import com.google.api.gax.rpc.UnknownException;
-import com.google.common.truth.Truth;
-import io.grpc.Status;
-import io.grpc.StatusException;
-import io.grpc.StatusRuntimeException;
-import java.util.Collections;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GrpcTransportDescriptorTest {
-  private static boolean NOT_RETRYABLE = false;
-  private static boolean IS_RETRYABLE = true;
-
-  @Test
-  public void translateException_StatusException_noRetry() {
-    Throwable originalException = new StatusException(Status.INVALID_ARGUMENT);
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(originalException), Collections.<StatusCode.Code>emptySet());
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, InvalidArgumentException.class, NOT_RETRYABLE, originalException);
-    }
-  }
-
-  @Test
-  public void translateException_StatusException_withRetry() {
-    Throwable originalException = new StatusException(Status.UNAVAILABLE);
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(originalException), Collections.singleton(Code.UNAVAILABLE));
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, UnavailableException.class, IS_RETRYABLE, originalException);
-    }
-  }
-
-  @Test
-  public void translateException_StatusRuntimeException_noRetry() {
-    Throwable originalException = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(originalException), Collections.<StatusCode.Code>emptySet());
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, InvalidArgumentException.class, NOT_RETRYABLE, originalException);
-    }
-  }
-
-  @Test
-  public void translateException_StatusRuntimeException_withRetry() {
-    Throwable originalException = new StatusRuntimeException(Status.UNAVAILABLE);
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(originalException), Collections.singleton(Code.UNAVAILABLE));
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, UnavailableException.class, IS_RETRYABLE, originalException);
-    }
-  }
-
-  @Test
-  public void translateException_cancelled() {
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(inactiveCallable(), Collections.<StatusCode.Code>emptySet());
-    ApiFuture<Integer> result = exceptionCallable.futureCall(0);
-    Truth.assertThat(result.isDone()).isFalse();
-    result.cancel(true);
-    Truth.assertThat(result.isCancelled()).isTrue();
-    Truth.assertThat(result.isDone()).isTrue();
-  }
-
-  @Test
-  public void translateException_ApiException() {
-    Throwable originalException = new RuntimeException("stuff went wrong");
-    Throwable apiException =
-        new DataLossException(
-            originalException, GrpcStatusCode.of(Status.Code.UNKNOWN), IS_RETRYABLE);
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(apiException), Collections.<StatusCode.Code>emptySet());
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, DataLossException.class, IS_RETRYABLE, originalException);
-    }
-  }
-
-  @Test
-  public void translateException_RuntimeException() {
-    Throwable originalException = new RuntimeException("stuff went wrong");
-    GrpcExceptionCallable<Integer, Integer> exceptionCallable =
-        new GrpcExceptionCallable<>(
-            failingCallable(originalException), Collections.<StatusCode.Code>emptySet());
-    try {
-      exceptionCallable.call(0);
-      fail("Expected exception to be thrown");
-    } catch (Throwable throwable) {
-      assertInnerExceptionIsInstanceOf(
-          throwable, UnknownException.class, NOT_RETRYABLE, originalException);
-    }
-  }
-
-  private UnaryCallable<Integer, Integer> failingCallable(final Throwable exception) {
-    return new UnaryCallable<Integer, Integer>() {
-      @Override
-      public ApiFuture<Integer> futureCall(Integer request, ApiCallContext context) {
-        return ApiFutures.immediateFailedFuture(exception);
-      }
-    };
-  }
-
-  private UnaryCallable<Integer, Integer> inactiveCallable() {
-    return new UnaryCallable<Integer, Integer>() {
-      @Override
-      public ApiFuture<Integer> futureCall(Integer request, ApiCallContext context) {
-        return SettableApiFuture.create();
-      }
-    };
-  }
-
-  public void assertInnerExceptionIsInstanceOf(
-      Throwable thrownException, Class<?> clazz, boolean retryable, Throwable originalException) {
-    Truth.assertThat(thrownException).isInstanceOf(clazz);
-    ApiException apiException = (ApiException) thrownException;
-    Truth.assertThat(apiException.isRetryable()).isEqualTo(retryable);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProviderTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProviderTest.java
deleted file mode 100644
index 654fc57b8..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProviderTest.java
+++ /dev/null
@@ -1,487 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider.Builder;
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.mtls.AbstractMtlsTransportChannelTest;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.auth.oauth2.CloudShellCredentials;
-import com.google.auth.oauth2.ComputeEngineCredentials;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import io.grpc.ManagedChannel;
-import io.grpc.ManagedChannelBuilder;
-import io.grpc.alts.ComputeEngineChannelBuilder;
-import java.io.IOException;
-import java.security.GeneralSecurityException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import javax.annotation.Nullable;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class InstantiatingGrpcChannelProviderTest extends AbstractMtlsTransportChannelTest {
-
-  @Test
-  public void testEndpoint() {
-    String endpoint = "localhost:8080";
-    InstantiatingGrpcChannelProvider.Builder builder =
-        InstantiatingGrpcChannelProvider.newBuilder();
-    builder.setEndpoint(endpoint);
-    assertEquals(builder.getEndpoint(), endpoint);
-
-    InstantiatingGrpcChannelProvider provider = builder.build();
-    assertEquals(provider.getEndpoint(), endpoint);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testEndpointNoPort() {
-    InstantiatingGrpcChannelProvider.newBuilder().setEndpoint("localhost");
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testEndpointBadPort() {
-    InstantiatingGrpcChannelProvider.newBuilder().setEndpoint("localhost:abcd");
-  }
-
-  @Test
-  public void testKeepAlive() {
-    Duration keepaliveTime = Duration.ofSeconds(1);
-    Duration keepaliveTimeout = Duration.ofSeconds(2);
-    boolean keepaliveWithoutCalls = true;
-
-    InstantiatingGrpcChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setKeepAliveTime(keepaliveTime)
-            .setKeepAliveTimeout(keepaliveTimeout)
-            .setKeepAliveWithoutCalls(keepaliveWithoutCalls)
-            .build();
-
-    assertEquals(provider.getKeepAliveTime(), keepaliveTime);
-    assertEquals(provider.getKeepAliveTimeout(), keepaliveTimeout);
-    assertEquals(provider.getKeepAliveWithoutCalls(), keepaliveWithoutCalls);
-  }
-
-  @Test
-  public void testMaxInboundMetadataSize() {
-    InstantiatingGrpcChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder().setMaxInboundMetadataSize(4096).build();
-    assertThat(provider.getMaxInboundMetadataSize()).isEqualTo(4096);
-  }
-
-  @Test
-  public void testCpuPoolSize() {
-    // happy path
-    Builder builder = InstantiatingGrpcChannelProvider.newBuilder().setProcessorCount(2);
-    builder.setChannelsPerCpu(2.5);
-    assertEquals(5, builder.getPoolSize());
-
-    // User specified max
-    builder = builder.setProcessorCount(50);
-    builder.setChannelsPerCpu(100, 10);
-    assertEquals(10, builder.getPoolSize());
-
-    // Sane default maximum
-    builder.setChannelsPerCpu(200);
-    assertEquals(100, builder.getPoolSize());
-  }
-
-  @Test
-  public void testWithPoolSize() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("localhost:8080");
-    assertThat(provider.acceptsPoolSize()).isTrue();
-
-    // Make sure we can create channels OK.
-    provider.getTransportChannel().shutdownNow();
-
-    provider = provider.withPoolSize(2);
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Test
-  public void testToBuilder() {
-    Duration keepaliveTime = Duration.ofSeconds(1);
-    Duration keepaliveTimeout = Duration.ofSeconds(2);
-    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-        builder -> {
-          throw new UnsupportedOperationException();
-        };
-    Map<String, ?> directPathServiceConfig = ImmutableMap.of("loadbalancingConfig", "grpclb");
-
-    InstantiatingGrpcChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setProcessorCount(2)
-            .setEndpoint("fake.endpoint:443")
-            .setMaxInboundMessageSize(12345678)
-            .setMaxInboundMetadataSize(4096)
-            .setKeepAliveTime(keepaliveTime)
-            .setKeepAliveTimeout(keepaliveTimeout)
-            .setKeepAliveWithoutCalls(true)
-            .setChannelConfigurator(channelConfigurator)
-            .setChannelsPerCpu(2.5)
-            .setDirectPathServiceConfig(directPathServiceConfig)
-            .build();
-
-    InstantiatingGrpcChannelProvider.Builder builder = provider.toBuilder();
-
-    assertThat(builder.getEndpoint()).isEqualTo("fake.endpoint:443");
-    assertThat(builder.getMaxInboundMessageSize()).isEqualTo(12345678);
-    assertThat(builder.getMaxInboundMetadataSize()).isEqualTo(4096);
-    assertThat(builder.getKeepAliveTime()).isEqualTo(keepaliveTime);
-    assertThat(builder.getKeepAliveTimeout()).isEqualTo(keepaliveTimeout);
-    assertThat(builder.getChannelConfigurator()).isEqualTo(channelConfigurator);
-    assertThat(builder.getPoolSize()).isEqualTo(5);
-    assertThat(builder.build().directPathServiceConfig).isEqualTo(directPathServiceConfig);
-  }
-
-  @Test
-  public void testWithInterceptors() throws Exception {
-    testWithInterceptors(1);
-  }
-
-  @Test
-  public void testWithInterceptorsAndMultipleChannels() throws Exception {
-    testWithInterceptors(5);
-  }
-
-  private void testWithInterceptors(int numChannels) throws Exception {
-    final GrpcInterceptorProvider interceptorProvider = Mockito.mock(GrpcInterceptorProvider.class);
-
-    InstantiatingGrpcChannelProvider channelProvider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setEndpoint("localhost:8080")
-            .setPoolSize(numChannels)
-            .setHeaderProvider(Mockito.mock(HeaderProvider.class))
-            .setExecutor(Mockito.mock(Executor.class))
-            .setInterceptorProvider(interceptorProvider)
-            .build();
-
-    Mockito.verify(interceptorProvider, Mockito.never()).getInterceptors();
-    channelProvider.getTransportChannel().shutdownNow();
-    Mockito.verify(interceptorProvider, Mockito.times(numChannels)).getInterceptors();
-  }
-
-  @Test
-  public void testChannelConfigurator() throws IOException {
-    final int numChannels = 5;
-
-    // Create a mock configurator that will insert mock channels
-    @SuppressWarnings("unchecked")
-    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-        Mockito.mock(ApiFunction.class);
-
-    ArgumentCaptor<ManagedChannelBuilder<?>> channelBuilderCaptor =
-        ArgumentCaptor.forClass(ManagedChannelBuilder.class);
-
-    ManagedChannelBuilder<?> swappedBuilder = Mockito.mock(ManagedChannelBuilder.class);
-    ManagedChannel fakeChannel = Mockito.mock(ManagedChannel.class);
-    Mockito.when(swappedBuilder.build()).thenReturn(fakeChannel);
-
-    Mockito.when(channelConfigurator.apply(channelBuilderCaptor.capture()))
-        .thenReturn(swappedBuilder);
-
-    // Invoke the provider
-    InstantiatingGrpcChannelProvider.newBuilder()
-        .setEndpoint("localhost:8080")
-        .setHeaderProvider(Mockito.mock(HeaderProvider.class))
-        .setExecutor(Mockito.mock(Executor.class))
-        .setChannelConfigurator(channelConfigurator)
-        .setPoolSize(numChannels)
-        .build()
-        .getTransportChannel();
-
-    // Make sure that the provider passed in a configured channel
-    assertThat(channelBuilderCaptor.getValue()).isNotNull();
-    // And that it was replaced with the mock
-    Mockito.verify(swappedBuilder, Mockito.times(numChannels)).build();
-  }
-
-  @Test
-  public void testWithGCECredentials() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setAttemptDirectPath(true)
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("localhost:8080");
-
-    assertThat(provider.needsCredentials()).isTrue();
-    if (InstantiatingGrpcChannelProvider.isOnComputeEngine()) {
-      provider = provider.withCredentials(ComputeEngineCredentials.create());
-    } else {
-      provider = provider.withCredentials(CloudShellCredentials.create(3000));
-    }
-    assertThat(provider.needsCredentials()).isFalse();
-
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Test
-  public void testWithNonGCECredentials() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-        channelBuilder -> {
-          // Clients with non-GCE credentials will not attempt DirectPath.
-          assertThat(channelBuilder instanceof ComputeEngineChannelBuilder).isFalse();
-          return channelBuilder;
-        };
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setAttemptDirectPath(true)
-            .setChannelConfigurator(channelConfigurator)
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("localhost:8080");
-
-    assertThat(provider.needsCredentials()).isTrue();
-    provider = provider.withCredentials(CloudShellCredentials.create(3000));
-    assertThat(provider.needsCredentials()).isFalse();
-
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Test
-  public void testWithDirectPathDisabled() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-        channelBuilder -> {
-          // Clients without setting attemptDirectPath flag will not attempt DirectPath
-          assertThat(channelBuilder instanceof ComputeEngineChannelBuilder).isFalse();
-          return channelBuilder;
-        };
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setAttemptDirectPath(false)
-            .setChannelConfigurator(channelConfigurator)
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("localhost:8080");
-
-    assertThat(provider.needsCredentials()).isTrue();
-    provider = provider.withCredentials(ComputeEngineCredentials.create());
-    assertThat(provider.needsCredentials()).isFalse();
-
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Test
-  public void testWithNoDirectPathFlagSet() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-        channelBuilder -> {
-          // Clients without setting attemptDirectPath flag will not attempt DirectPath
-          assertThat(channelBuilder instanceof ComputeEngineChannelBuilder).isFalse();
-          return channelBuilder;
-        };
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setChannelConfigurator(channelConfigurator)
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("localhost:8080");
-
-    assertThat(provider.needsCredentials()).isTrue();
-    provider = provider.withCredentials(ComputeEngineCredentials.create());
-    assertThat(provider.needsCredentials()).isFalse();
-
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Test
-  public void testWithIPv6Address() throws IOException {
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    TransportChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .build()
-            .withExecutor((Executor) executor)
-            .withHeaders(Collections.<String, String>emptyMap())
-            .withEndpoint("[::1]:8080");
-    assertThat(provider.needsEndpoint()).isFalse();
-
-    // Make sure we can create channels OK.
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  // Test that if ChannelPrimer is provided, it is called during creation
-  @Test
-  public void testWithPrimeChannel() throws IOException {
-    // create channelProvider with different pool sizes to verify ChannelPrimer is called the
-    // correct number of times
-    for (int poolSize = 1; poolSize < 5; poolSize++) {
-      final ChannelPrimer mockChannelPrimer = Mockito.mock(ChannelPrimer.class);
-
-      InstantiatingGrpcChannelProvider provider =
-          InstantiatingGrpcChannelProvider.newBuilder()
-              .setEndpoint("localhost:8080")
-              .setPoolSize(poolSize)
-              .setHeaderProvider(Mockito.mock(HeaderProvider.class))
-              .setExecutor(Mockito.mock(Executor.class))
-              .setChannelPrimer(mockChannelPrimer)
-              .build();
-
-      provider.getTransportChannel().shutdownNow();
-
-      // every channel in the pool should call primeChannel during creation.
-      Mockito.verify(mockChannelPrimer, Mockito.times(poolSize))
-          .primeChannel(Mockito.any(ManagedChannel.class));
-    }
-  }
-
-  @Test
-  public void testWithDefaultDirectPathServiceConfig() {
-    InstantiatingGrpcChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder().build();
-
-    ImmutableMap<String, ?> defaultServiceConfig = provider.directPathServiceConfig;
-
-    List<Map<String, ?>> lbConfigs = getAsObjectList(defaultServiceConfig, "loadBalancingConfig");
-    assertThat(lbConfigs).hasSize(1);
-    Map<String, ?> lbConfig = lbConfigs.get(0);
-    Map<String, ?> grpclb = getAsObject(lbConfig, "grpclb");
-    List<Map<String, ?>> childPolicies = getAsObjectList(grpclb, "childPolicy");
-    assertThat(childPolicies).hasSize(1);
-    Map<String, ?> childPolicy = childPolicies.get(0);
-    assertThat(childPolicy.keySet()).containsExactly("pick_first");
-  }
-
-  @Nullable
-  private static Map<String, ?> getAsObject(Map<String, ?> json, String key) {
-    Object mapObject = json.get(key);
-    if (mapObject == null) {
-      return null;
-    }
-    return checkObject(mapObject);
-  }
-
-  @SuppressWarnings("unchecked")
-  private static Map<String, ?> checkObject(Object json) {
-    checkArgument(json instanceof Map, "Invalid json object representation: %s", json);
-    for (Map.Entry<Object, Object> entry : ((Map<Object, Object>) json).entrySet()) {
-      checkArgument(entry.getKey() instanceof String, "Key is not string");
-    }
-    return (Map<String, ?>) json;
-  }
-
-  private static List<Map<String, ?>> getAsObjectList(Map<String, ?> json, String key) {
-    Object listObject = json.get(key);
-    if (listObject == null) {
-      return null;
-    }
-    return checkListOfObjects(listObject);
-  }
-
-  @SuppressWarnings("unchecked")
-  private static List<Map<String, ?>> checkListOfObjects(Object listObject) {
-    checkArgument(listObject instanceof List, "Passed object is not a list");
-    List<Map<String, ?>> list = new ArrayList<>();
-    for (Object object : ((List<Object>) listObject)) {
-      list.add(checkObject(object));
-    }
-    return list;
-  }
-
-  @Test
-  public void testWithCustomDirectPathServiceConfig() {
-    ImmutableMap<String, Object> pickFirstStrategy =
-        ImmutableMap.<String, Object>of("round_robin", ImmutableMap.of());
-    ImmutableMap<String, Object> childPolicy =
-        ImmutableMap.<String, Object>of(
-            "childPolicy", ImmutableList.of(pickFirstStrategy), "foo", "bar");
-    ImmutableMap<String, Object> grpcLbPolicy =
-        ImmutableMap.<String, Object>of("grpclb", childPolicy);
-    Map<String, Object> passedServiceConfig = new HashMap<>();
-    passedServiceConfig.put("loadBalancingConfig", ImmutableList.of(grpcLbPolicy));
-
-    InstantiatingGrpcChannelProvider provider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setDirectPathServiceConfig(passedServiceConfig)
-            .build();
-
-    ImmutableMap<String, ?> defaultServiceConfig = provider.directPathServiceConfig;
-    assertThat(defaultServiceConfig).isEqualTo(passedServiceConfig);
-  }
-
-  @Override
-  protected Object getMtlsObjectFromTransportChannel(MtlsProvider provider)
-      throws IOException, GeneralSecurityException {
-    InstantiatingGrpcChannelProvider channelProvider =
-        InstantiatingGrpcChannelProvider.newBuilder()
-            .setEndpoint("localhost:8080")
-            .setMtlsProvider(provider)
-            .setHeaderProvider(Mockito.mock(HeaderProvider.class))
-            .setExecutor(Mockito.mock(Executor.class))
-            .build();
-    return channelProvider.createMtlsChannelCredentials();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockClientCall.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/MockClientCall.java
deleted file mode 100644
index a1720293f..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockClientCall.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import io.grpc.ClientCall;
-import io.grpc.Metadata;
-import io.grpc.Status;
-import javax.annotation.Nullable;
-
-public class MockClientCall<RequestT, ResponseT> extends ClientCall<RequestT, ResponseT> {
-
-  private ResponseT response;
-  private Listener<ResponseT> responseListener;
-  private Metadata headers;
-  private Status status;
-
-  public MockClientCall(ResponseT response, Status status) {
-    this.response = response;
-    this.status = status;
-  }
-
-  @Override
-  public synchronized void start(Listener<ResponseT> responseListener, Metadata headers) {
-    this.responseListener = responseListener;
-    this.headers = headers;
-  }
-
-  @Override
-  public void request(int numMessages) {}
-
-  @Override
-  public void cancel(@Nullable String message, @Nullable Throwable cause) {}
-
-  @Override
-  public void halfClose() {}
-
-  @Override
-  public void sendMessage(RequestT message) {
-    responseListener.onHeaders(headers);
-    responseListener.onMessage(response);
-    responseListener.onClose(status, headers);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsEx.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsEx.java
deleted file mode 100644
index 0f6c3fd8a..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsEx.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.grpc.testing.MockGrpcService;
-import com.google.protobuf.AbstractMessage;
-import io.grpc.ServerServiceDefinition;
-import java.util.List;
-
-/** A MockGrpcService for OperationsApi which uses MockOperationsExImpl. */
-@BetaApi
-public class MockOperationsEx implements MockGrpcService {
-  private final MockOperationsExImpl serviceImpl;
-
-  public MockOperationsEx() {
-    serviceImpl = new MockOperationsExImpl();
-  }
-
-  @Override
-  public List<AbstractMessage> getRequests() {
-    return serviceImpl.getRequests();
-  }
-
-  @Override
-  public void addResponse(AbstractMessage response) {
-    serviceImpl.addGetOperationResponse(response);
-  }
-
-  @Override
-  public void addException(Exception error) {
-    serviceImpl.addGetOperationError(error);
-  }
-
-  @Override
-  public ServerServiceDefinition getServiceDefinition() {
-    return serviceImpl.bindService();
-  }
-
-  @Override
-  public void reset() {
-    serviceImpl.reset();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsExImpl.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsExImpl.java
deleted file mode 100644
index 055e7cdca..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/MockOperationsExImpl.java
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import com.google.api.core.BetaApi;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.longrunning.OperationsGrpc.OperationsImplBase;
-import com.google.protobuf.AbstractMessage;
-import com.google.protobuf.Empty;
-import io.grpc.stub.StreamObserver;
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-/** A custom mock Operations service implementation which only mocks responses for GetOperation. */
-@BetaApi
-public class MockOperationsExImpl extends OperationsImplBase {
-  private List<AbstractMessage> requests;
-  private Queue<Object> getOperationResponses;
-
-  public MockOperationsExImpl() {
-    requests = new ArrayList<>();
-    getOperationResponses = new LinkedList<>();
-  }
-
-  public List<AbstractMessage> getRequests() {
-    return requests;
-  }
-
-  public void addGetOperationResponse(AbstractMessage response) {
-    this.getOperationResponses.add(response);
-  }
-
-  public void addGetOperationError(Throwable error) {
-    this.getOperationResponses.add(error);
-  }
-
-  public void reset() {
-    requests = new ArrayList<>();
-    getOperationResponses = new LinkedList<>();
-  }
-
-  @Override
-  public void getOperation(
-      GetOperationRequest request, StreamObserver<Operation> responseObserver) {
-    requests.add(request);
-    Object response = getOperationResponses.remove();
-    if (response instanceof Throwable) {
-      responseObserver.onError((Throwable) response);
-    } else if (response instanceof AbstractMessage) {
-      responseObserver.onNext((Operation) response);
-      responseObserver.onCompleted();
-    }
-  }
-
-  @Override
-  public void listOperations(
-      ListOperationsRequest request, StreamObserver<ListOperationsResponse> responseObserver) {
-    requests.add(request);
-    responseObserver.onError(
-        new UnsupportedOperationException(
-            "MockOperationsExImpl: listOperations not yet supported"));
-  }
-
-  @Override
-  public void cancelOperation(
-      CancelOperationRequest request, StreamObserver<Empty> responseObserver) {
-    requests.add(request);
-    responseObserver.onNext(Empty.getDefaultInstance());
-    responseObserver.onCompleted();
-  }
-
-  @Override
-  public void deleteOperation(
-      DeleteOperationRequest request, StreamObserver<Empty> responseObserver) {
-    requests.add(request);
-    responseObserver.onError(
-        new UnsupportedOperationException(
-            "MockOperationsExImpl: listOperations not yet supported"));
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/ProtoOperationTransformersTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/ProtoOperationTransformersTest.java
deleted file mode 100644
index 5ac43f141..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/ProtoOperationTransformersTest.java
+++ /dev/null
@@ -1,116 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertThrows;
-
-import com.google.api.gax.grpc.ProtoOperationTransformers.MetadataTransformer;
-import com.google.api.gax.grpc.ProtoOperationTransformers.ResponseTransformer;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.UnavailableException;
-import com.google.api.gax.rpc.UnknownException;
-import com.google.common.truth.Truth;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Any;
-import com.google.rpc.Status;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.Status.Code;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ProtoOperationTransformersTest {
-  @Test
-  public void testAnyResponseTransformer() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    OperationSnapshot operationSnapshot =
-        GrpcOperationSnapshot.create(
-            Operation.newBuilder().setResponse(Any.pack(inputMoney)).build());
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testAnyResponseTransformer_exception() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    Status status = Status.newBuilder().setCode(Code.UNAVAILABLE.value()).build();
-    OperationSnapshot operationSnapshot =
-        GrpcOperationSnapshot.create(
-            Operation.newBuilder().setResponse(Any.pack(inputMoney)).setError(status).build());
-    Exception exception =
-        assertThrows(UnavailableException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception)
-        .hasMessageThat()
-        .contains("failed with status = GrpcStatusCode{transportCode=UNAVAILABLE}");
-  }
-
-  @Test
-  public void testAnyResponseTransformer_mismatchedTypes() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Status status = Status.newBuilder().setCode(Code.OK.value()).build();
-    OperationSnapshot operationSnapshot =
-        GrpcOperationSnapshot.create(
-            Operation.newBuilder()
-                .setResponse(Any.pack(Color.getDefaultInstance()))
-                .setError(status)
-                .build());
-    Exception exception =
-        assertThrows(UnknownException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception).hasMessageThat().contains("encountered a problem unpacking it");
-  }
-
-  @Test
-  public void testAnyMetadataTransformer() {
-    MetadataTransformer<Money> transformer = MetadataTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    OperationSnapshot operationSnapshot =
-        GrpcOperationSnapshot.create(
-            Operation.newBuilder().setMetadata(Any.pack(inputMoney)).build());
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testAnyMetadataTransformer_mismatchedTypes() {
-    MetadataTransformer<Money> transformer = MetadataTransformer.create(Money.class);
-    Status status = Status.newBuilder().setCode(Code.OK.value()).build();
-    OperationSnapshot operationSnapshot =
-        GrpcOperationSnapshot.create(
-            Operation.newBuilder()
-                .setMetadata(Any.pack(Color.getDefaultInstance()))
-                .setError(status)
-                .build());
-    Exception exception =
-        assertThrows(UnknownException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception).hasMessageThat().contains("encountered a problem unpacking it");
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/SettingsTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/SettingsTest.java
deleted file mode 100644
index e24e36c68..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/SettingsTest.java
+++ /dev/null
@@ -1,366 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static org.junit.Assert.assertEquals;
-
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.core.CredentialsProvider;
-import com.google.api.gax.core.FixedCredentialsProvider;
-import com.google.api.gax.core.GoogleCredentialsProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.paging.PagedListResponse;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.BatchingDescriptor;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.FixedWatchdogProvider;
-import com.google.api.gax.rpc.NoHeaderProvider;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.PagedListResponseFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StubSettings;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import java.io.IOException;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class SettingsTest {
-
-  interface FakePagedListResponse extends PagedListResponse<Integer> {}
-
-  private static class FakeStubSettings extends StubSettings<FakeStubSettings> {
-
-    @SuppressWarnings("unchecked")
-    private static final PagedListResponseFactory<Integer, Integer, FakePagedListResponse>
-        fakePagedListResponseFactory = Mockito.mock(PagedListResponseFactory.class);
-
-    @SuppressWarnings("unchecked")
-    private static final BatchingDescriptor<Integer, Integer> FAKE_BATCHING_DESCRIPTOR =
-        Mockito.mock(BatchingDescriptor.class);
-
-    private static final String DEFAULT_GAPIC_NAME = "gapic";
-    public static final String DEFAULT_SERVICE_ADDRESS = "pubsub-experimental.googleapis.com";
-    public static final int DEFAULT_SERVICE_PORT = 443;
-    public static final String DEFAULT_SERVICE_ENDPOINT =
-        DEFAULT_SERVICE_ADDRESS + ':' + DEFAULT_SERVICE_PORT;
-    public static final MtlsProvider DEFAULT_MTLS_PROVIDER = new MtlsProvider();
-    public static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
-        ImmutableList.<String>builder()
-            .add("https://www.googleapis.com/auth/pubsub")
-            .add("https://www.googleapis.com/auth/cloud-platform")
-            .build();
-
-    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
-        RETRYABLE_CODE_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
-          ImmutableMap.builder();
-      definitions.put(
-          "idempotent",
-          ImmutableSet.copyOf(
-              Lists.newArrayList(StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
-      definitions.put("non_idempotent", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
-      RETRYABLE_CODE_DEFINITIONS = definitions.build();
-    }
-
-    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
-      RetrySettings settings = null;
-      settings =
-          RetrySettings.newBuilder()
-              .setInitialRetryDelay(Duration.ofMillis(100L))
-              .setRetryDelayMultiplier(1.2)
-              .setMaxRetryDelay(Duration.ofMillis(1000L))
-              .setInitialRpcTimeout(Duration.ofMillis(2000L))
-              .setRpcTimeoutMultiplier(1.5)
-              .setMaxRpcTimeout(Duration.ofMillis(30000L))
-              .setTotalTimeout(Duration.ofMillis(45000L))
-              .build();
-      definitions.put("default", settings);
-      RETRY_PARAM_DEFINITIONS = definitions.build();
-    }
-
-    private final UnaryCallSettings<Integer, Integer> fakeMethodSimple;
-    private final PagedCallSettings<Integer, Integer, FakePagedListResponse> fakePagedMethod;
-    private final BatchingCallSettings<Integer, Integer> fakeMethodBatching;
-
-    public UnaryCallSettings<Integer, Integer> fakeMethodSimple() {
-      return fakeMethodSimple;
-    }
-
-    public PagedCallSettings<Integer, Integer, FakePagedListResponse> fakePagedMethod() {
-      return fakePagedMethod;
-    }
-
-    public BatchingCallSettings<Integer, Integer> fakeMethodBatching() {
-      return fakeMethodBatching;
-    }
-
-    public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-      return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
-    }
-
-    public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
-      return InstantiatingExecutorProvider.newBuilder();
-    }
-
-    /** Returns a builder for the default TransportChannelProvider for this service. */
-    public static InstantiatingGrpcChannelProvider.Builder defaultGrpcChannelProviderBuilder() {
-      return InstantiatingGrpcChannelProvider.newBuilder()
-          .setEndpoint(DEFAULT_SERVICE_ENDPOINT)
-          .setMtlsProvider(DEFAULT_MTLS_PROVIDER);
-    }
-
-    public static ApiClientHeaderProvider.Builder defaultGoogleServiceHeaderProviderBuilder() {
-      return ApiClientHeaderProvider.newBuilder()
-          .setGeneratedLibToken(DEFAULT_GAPIC_NAME, "0.10.0")
-          .setTransportToken(
-              GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion());
-    }
-
-    public static TransportChannelProvider defaultTransportChannelProvider() {
-      return defaultGrpcChannelProviderBuilder().build();
-    }
-
-    public static Builder newBuilder() {
-      return Builder.createDefault();
-    }
-
-    @Override
-    public Builder toBuilder() {
-      return new Builder(this);
-    }
-
-    private FakeStubSettings(Builder settingsBuilder) {
-      super(settingsBuilder);
-
-      fakeMethodSimple = settingsBuilder.fakeMethodSimple().build();
-      fakePagedMethod = settingsBuilder.fakePagedMethod().build();
-      fakeMethodBatching = settingsBuilder.fakeMethodBatching().build();
-    }
-
-    private static class Builder extends StubSettings.Builder<FakeStubSettings, Builder> {
-
-      private UnaryCallSettings.Builder<Integer, Integer> fakeMethodSimple;
-      private PagedCallSettings.Builder<Integer, Integer, FakePagedListResponse> fakePagedMethod;
-      private BatchingCallSettings.Builder<Integer, Integer> fakeMethodBatching;
-
-      private Builder() {
-        super((ClientContext) null);
-
-        fakeMethodSimple = UnaryCallSettings.newUnaryCallSettingsBuilder();
-        fakePagedMethod = PagedCallSettings.newBuilder(fakePagedListResponseFactory);
-        fakeMethodBatching =
-            BatchingCallSettings.newBuilder(FAKE_BATCHING_DESCRIPTOR)
-                .setBatchingSettings(BatchingSettings.newBuilder().build());
-      }
-
-      private static Builder createDefault() {
-        Builder builder = new Builder();
-        builder.setTransportChannelProvider(defaultTransportChannelProvider());
-        builder.setExecutorProvider(defaultExecutorProviderBuilder().build());
-        builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
-        builder.setHeaderProvider(new NoHeaderProvider());
-        builder.setInternalHeaderProvider(defaultGoogleServiceHeaderProviderBuilder().build());
-        builder.setStreamWatchdogProvider(FixedWatchdogProvider.create(null));
-
-        builder
-            .fakeMethodSimple()
-            .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-            .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-        builder
-            .fakePagedMethod()
-            .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-            .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-        builder
-            .fakeMethodBatching()
-            .setBatchingSettings(
-                BatchingSettings.newBuilder()
-                    .setElementCountThreshold(800L)
-                    .setRequestByteThreshold(8388608L)
-                    .setDelayThreshold(Duration.ofMillis(100))
-                    .build());
-        builder
-            .fakeMethodBatching()
-            .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-            .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
-
-        return builder;
-      }
-
-      private Builder(FakeStubSettings settings) {
-        super(settings);
-
-        fakeMethodSimple = settings.fakeMethodSimple().toBuilder();
-        fakePagedMethod = settings.fakePagedMethod().toBuilder();
-        fakeMethodBatching = settings.fakeMethodBatching().toBuilder();
-      }
-
-      @Override
-      public FakeStubSettings build() throws IOException {
-        return new FakeStubSettings(this);
-      }
-
-      public UnaryCallSettings.Builder<Integer, Integer> fakeMethodSimple() {
-        return fakeMethodSimple;
-      }
-
-      public PagedCallSettings.Builder<Integer, Integer, FakePagedListResponse> fakePagedMethod() {
-        return fakePagedMethod;
-      }
-
-      public BatchingCallSettings.Builder<Integer, Integer> fakeMethodBatching() {
-        return fakeMethodBatching;
-      }
-    }
-  }
-
-  // GrpcTransportProvider
-  // ====
-
-  @Test
-  public void customCredentials() throws IOException {
-    Credentials credentials = Mockito.mock(Credentials.class);
-
-    FakeStubSettings settings =
-        FakeStubSettings.newBuilder()
-            .setCredentialsProvider(FixedCredentialsProvider.create(credentials))
-            .build();
-
-    TransportChannelProvider actualChannelProvider = settings.getTransportChannelProvider();
-    Truth.assertThat(actualChannelProvider).isInstanceOf(InstantiatingGrpcChannelProvider.class);
-    InstantiatingGrpcChannelProvider actualInstChPr =
-        (InstantiatingGrpcChannelProvider) actualChannelProvider;
-
-    Truth.assertThat(actualInstChPr.getEndpoint())
-        .isEqualTo(FakeStubSettings.DEFAULT_SERVICE_ENDPOINT);
-    // TODO(michaelbausor): create JSON with credentials and define GOOGLE_APPLICATION_CREDENTIALS
-    // environment variable to allow travis build to access application default credentials
-    Truth.assertThat(settings.getCredentialsProvider().getCredentials())
-        .isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void channelCustomCredentialScopes() throws IOException {
-    ImmutableList<String> inputScopes =
-        ImmutableList.<String>builder().add("https://www.googleapis.com/auth/fakeservice").build();
-
-    CredentialsProvider credentialsProvider =
-        FakeStubSettings.defaultCredentialsProviderBuilder().setScopesToApply(inputScopes).build();
-    FakeStubSettings settings =
-        FakeStubSettings.newBuilder().setCredentialsProvider(credentialsProvider).build();
-
-    TransportChannelProvider actualChannelProvider = settings.getTransportChannelProvider();
-    Truth.assertThat(actualChannelProvider).isInstanceOf(InstantiatingGrpcChannelProvider.class);
-    InstantiatingGrpcChannelProvider actualInstChPr =
-        (InstantiatingGrpcChannelProvider) actualChannelProvider;
-
-    Truth.assertThat(actualInstChPr.getEndpoint())
-        .isEqualTo(FakeStubSettings.DEFAULT_SERVICE_ENDPOINT);
-
-    CredentialsProvider actualCredentialsProvider = settings.getCredentialsProvider();
-    Truth.assertThat(actualCredentialsProvider).isInstanceOf(GoogleCredentialsProvider.class);
-    GoogleCredentialsProvider googCredProv = (GoogleCredentialsProvider) actualCredentialsProvider;
-
-    Truth.assertThat(googCredProv.getScopesToApply()).isEqualTo(inputScopes);
-
-    // TODO(michaelbausor): create JSON with credentials and define GOOGLE_APPLICATION_CREDENTIALS
-    // environment variable to allow travis build to access application default credentials
-    // Truth.assertThat(connSettings.getCredentials()).isNotNull();
-  }
-
-  // CallSettings
-  // ====
-
-  @Test
-  public void callSettingsToBuilder() {
-    UnaryCallSettings.Builder<?, ?> builderA = UnaryCallSettings.newUnaryCallSettingsBuilder();
-    UnaryCallSettings<?, ?> settingsA = builderA.build();
-    UnaryCallSettings.Builder<?, ?> builderB = settingsA.toBuilder();
-    UnaryCallSettings<?, ?> settingsB = builderB.build();
-
-    assertEquals(settingsA, settingsB);
-  }
-
-  @Test
-  public void unaryCallSettingsBuilderBuildDoesNotFailUnsetProperties() {
-    UnaryCallSettings.Builder<Integer, Integer> builder =
-        UnaryCallSettings.newUnaryCallSettingsBuilder();
-    builder.build();
-  }
-
-  @Test
-  public void callSettingsBuildFromTimeoutNoRetries() {
-    Duration timeout = Duration.ofMillis(60000);
-
-    UnaryCallSettings.Builder<Integer, Integer> builderA =
-        UnaryCallSettings.newUnaryCallSettingsBuilder();
-    builderA.setSimpleTimeoutNoRetries(timeout);
-    UnaryCallSettings<Integer, Integer> settingsA = builderA.build();
-
-    UnaryCallSettings.Builder<Integer, Integer> builderB =
-        UnaryCallSettings.newUnaryCallSettingsBuilder();
-    builderB
-        .setRetryableCodes()
-        .setRetrySettings(
-            RetrySettings.newBuilder()
-                .setTotalTimeout(timeout)
-                .setInitialRetryDelay(Duration.ZERO)
-                .setRetryDelayMultiplier(1)
-                .setMaxRetryDelay(Duration.ZERO)
-                .setInitialRpcTimeout(timeout)
-                .setRpcTimeoutMultiplier(1)
-                .setMaxRpcTimeout(timeout)
-                .setMaxAttempts(1)
-                .build());
-    UnaryCallSettings<Integer, Integer> settingsB = builderB.build();
-
-    assertEquals("UnaryCallSettings", settingsA, settingsB);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/TimeoutTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/TimeoutTest.java
deleted file mode 100644
index 3b0d8ebc5..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/TimeoutTest.java
+++ /dev/null
@@ -1,447 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.times;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.collect.ImmutableSet;
-import io.grpc.CallOptions;
-import io.grpc.ClientCall;
-import io.grpc.Deadline;
-import io.grpc.ManagedChannel;
-import io.grpc.MethodDescriptor;
-import io.grpc.MethodDescriptor.Marshaller;
-import io.grpc.MethodDescriptor.MethodType;
-import java.util.concurrent.TimeUnit;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.ArgumentMatchers;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class TimeoutTest {
-  private static final String CALL_OPTIONS_AUTHORITY = "RETRYING_TEST";
-  private static final int DEADLINE_IN_DAYS = 7;
-  private static final int DEADLINE_IN_MINUTES = 10;
-  private static final int DEADLINE_IN_SECONDS = 20;
-  private static final ImmutableSet<StatusCode.Code> emptyRetryCodes = ImmutableSet.of();
-  private static final ImmutableSet<StatusCode.Code> retryUnknownCode =
-      ImmutableSet.of(StatusCode.Code.UNKNOWN);
-  private static final Duration totalTimeout = Duration.ofDays(DEADLINE_IN_DAYS);
-  private static final Duration maxRpcTimeout = Duration.ofMinutes(DEADLINE_IN_MINUTES);
-  private static final Duration initialRpcTimeout = Duration.ofSeconds(DEADLINE_IN_SECONDS);
-  private static final GrpcCallContext defaultCallContext = GrpcCallContext.createDefault();
-
-  @Rule public MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-  @Mock private Marshaller<String> stringMarshaller;
-  @Mock private RequestParamsExtractor<String> paramsExtractor;
-  @Mock private ManagedChannel managedChannel;
-
-  @Test
-  public void testNonRetryUnarySettings() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setInitialRpcTimeout(initialRpcTimeout)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    CallOptions callOptionsUsed =
-        setupUnaryCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryUnarySettingsContextWithRetry() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setInitialRpcTimeout(initialRpcTimeout)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    Duration newTimeout = Duration.ofSeconds(5);
-    RetrySettings contextRetrySettings =
-        retrySettings
-            .toBuilder()
-            .setInitialRpcTimeout(newTimeout)
-            .setMaxRpcTimeout(newTimeout)
-            .setMaxAttempts(3)
-            .build();
-    GrpcCallContext retryingContext =
-        defaultCallContext
-            .withRetrySettings(contextRetrySettings)
-            .withRetryableCodes(retryUnknownCode);
-    CallOptions callOptionsUsed =
-        setupUnaryCallable(retrySettings, emptyRetryCodes, retryingContext);
-
-    // Verify that the gRPC channel used the CallOptions the initial timeout of ~5 seconds.
-    // This indicates that the context retry settings were used on a callable that was instantiated
-    // with non-retryable settings.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(toSecondsPart(newTimeout) - 1, TimeUnit.SECONDS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(toSecondsPart(newTimeout), TimeUnit.SECONDS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryUnarySettingsWithoutInitialRpcTimeout() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    CallOptions callOptionsUsed =
-        setupUnaryCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryUnarySettingsWithoutIndividualRpcTimeout() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setRpcTimeoutMultiplier(1.0)
-            .setRpcTimeoutMultiplier(1.0)
-            .build();
-    CallOptions callOptionsUsed =
-        setupUnaryCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryServerStreamingSettings() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setInitialRpcTimeout(initialRpcTimeout)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    CallOptions callOptionsUsed =
-        setupServerStreamingCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryServerStreamingSettingsContextWithRetry() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setInitialRpcTimeout(initialRpcTimeout)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    Duration newTimeout = Duration.ofSeconds(5);
-    RetrySettings contextRetrySettings =
-        retrySettings.toBuilder().setTotalTimeout(newTimeout).setMaxAttempts(3).build();
-    GrpcCallContext retryingContext =
-        defaultCallContext
-            .withRetrySettings(contextRetrySettings)
-            .withRetryableCodes(retryUnknownCode);
-    CallOptions callOptionsUsed =
-        setupServerStreamingCallable(retrySettings, emptyRetryCodes, retryingContext);
-
-    // Verify that the gRPC channel used the CallOptions the total timeout of ~5 seconds.
-    // This indicates that the context retry settings were used on a callable that was instantiated
-    // with non-retryable settings.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(toSecondsPart(newTimeout) - 1, TimeUnit.SECONDS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(toSecondsPart(newTimeout), TimeUnit.SECONDS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryServerStreamingSettingsWithoutInitialRpcTimeout() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setRpcTimeoutMultiplier(1.0)
-            .setMaxRpcTimeout(maxRpcTimeout)
-            .build();
-    CallOptions callOptionsUsed =
-        setupServerStreamingCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  @Test
-  public void testNonRetryServerStreamingSettingsWithoutIndividualRpcTimeout() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(totalTimeout)
-            .setInitialRetryDelay(Duration.ZERO)
-            .setRetryDelayMultiplier(1.0)
-            .setMaxRetryDelay(Duration.ZERO)
-            .setMaxAttempts(1)
-            .setJittered(true)
-            .setRpcTimeoutMultiplier(1.0)
-            .setRpcTimeoutMultiplier(1.0)
-            .build();
-    CallOptions callOptionsUsed =
-        setupServerStreamingCallable(retrySettings, emptyRetryCodes, defaultCallContext);
-
-    // Verify that the gRPC channel used the CallOptions with our custom timeout of ~2 Days.
-    assertThat(callOptionsUsed.getDeadline()).isNotNull();
-    assertThat(callOptionsUsed.getDeadline())
-        .isGreaterThan(Deadline.after(DEADLINE_IN_DAYS - 1, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getDeadline())
-        .isLessThan(Deadline.after(DEADLINE_IN_DAYS, TimeUnit.DAYS));
-    assertThat(callOptionsUsed.getAuthority()).isEqualTo(CALL_OPTIONS_AUTHORITY);
-  }
-
-  private CallOptions setupUnaryCallable(
-      RetrySettings retrySettings,
-      ImmutableSet<StatusCode.Code> retryableCodes,
-      GrpcCallContext callContext) {
-    MethodDescriptor<String, String> methodDescriptor =
-        MethodDescriptor.<String, String>newBuilder()
-            .setSchemaDescriptor("yaml")
-            .setFullMethodName("fake.test/RingRing")
-            .setResponseMarshaller(stringMarshaller)
-            .setRequestMarshaller(stringMarshaller)
-            .setType(MethodType.UNARY)
-            .build();
-
-    @SuppressWarnings("unchecked")
-    ClientCall<String, String> clientCall = Mockito.mock(ClientCall.class);
-    Mockito.doReturn(clientCall)
-        .when(managedChannel)
-        .newCall(ArgumentMatchers.eq(methodDescriptor), ArgumentMatchers.any(CallOptions.class));
-
-    // Clobber the "authority" property with an identifier that allows us to trace
-    // the use of this CallOptions variable.
-    CallOptions spyCallOptions = CallOptions.DEFAULT.withAuthority("RETRYING_TEST");
-    GrpcCallContext context =
-        callContext.withChannel(managedChannel).withCallOptions(spyCallOptions);
-
-    ArgumentCaptor<CallOptions> callOptionsArgumentCaptor =
-        ArgumentCaptor.forClass(CallOptions.class);
-
-    // Throw an exception during the gRPC channel business so we don't have to deal with
-    // processing the channel output.
-    Mockito.doThrow(
-            new ApiException(new RuntimeException(), FakeStatusCode.of(Code.UNAVAILABLE), false))
-        .when(clientCall)
-        .halfClose();
-
-    GrpcCallSettings<String, String> grpcCallSettings =
-        GrpcCallSettings.<String, String>newBuilder()
-            .setMethodDescriptor(methodDescriptor)
-            .setParamsExtractor(paramsExtractor)
-            .build();
-    UnaryCallSettings<String, String> unaryCallSettings =
-        UnaryCallSettings.<String, String>newUnaryCallSettingsBuilder()
-            .setRetrySettings(retrySettings)
-            .setRetryableCodes(retryableCodes)
-            .build();
-    UnaryCallable<String, String> callable =
-        GrpcCallableFactory.createUnaryCallable(
-            grpcCallSettings,
-            unaryCallSettings,
-            ClientContext.newBuilder().setDefaultCallContext(context).build());
-
-    try {
-      callable.futureCall("Is your refrigerator running?");
-    } catch (ApiException e) {
-    }
-
-    Mockito.verify(managedChannel, times(1))
-        .newCall(ArgumentMatchers.eq(methodDescriptor), callOptionsArgumentCaptor.capture());
-    return callOptionsArgumentCaptor.getValue();
-  }
-
-  private CallOptions setupServerStreamingCallable(
-      RetrySettings retrySettings,
-      ImmutableSet<StatusCode.Code> retryableCodes,
-      GrpcCallContext callContext) {
-    MethodDescriptor<String, String> methodDescriptor =
-        MethodDescriptor.<String, String>newBuilder()
-            .setSchemaDescriptor("yaml")
-            .setFullMethodName("fake.test/RingRing")
-            .setResponseMarshaller(stringMarshaller)
-            .setRequestMarshaller(stringMarshaller)
-            .setType(MethodType.SERVER_STREAMING)
-            .build();
-
-    @SuppressWarnings("unchecked")
-    ClientCall<String, String> clientCall = Mockito.mock(ClientCall.class);
-    Mockito.doReturn(clientCall)
-        .when(managedChannel)
-        .newCall(ArgumentMatchers.eq(methodDescriptor), ArgumentMatchers.any(CallOptions.class));
-
-    // Clobber the "authority" property with an identifier that allows us to trace
-    // the use of this CallOptions variable.
-    CallOptions spyCallOptions = CallOptions.DEFAULT.withAuthority("RETRYING_TEST");
-    GrpcCallContext context =
-        callContext.withChannel(managedChannel).withCallOptions(spyCallOptions);
-
-    ArgumentCaptor<CallOptions> callOptionsArgumentCaptor =
-        ArgumentCaptor.forClass(CallOptions.class);
-
-    // Throw an exception during the gRPC channel business so we don't have to deal with
-    // processing the channel output.
-    Mockito.doThrow(
-            new ApiException(new RuntimeException(), FakeStatusCode.of(Code.UNAVAILABLE), false))
-        .when(clientCall)
-        .halfClose();
-
-    GrpcCallSettings<String, String> grpcCallSettings =
-        GrpcCallSettings.<String, String>newBuilder()
-            .setMethodDescriptor(methodDescriptor)
-            .setParamsExtractor(paramsExtractor)
-            .build();
-    ServerStreamingCallSettings<String, String> serverStreamingCallSettings =
-        ServerStreamingCallSettings.<String, String>newBuilder()
-            .setRetrySettings(retrySettings)
-            .setRetryableCodes(retryableCodes)
-            .build();
-    ServerStreamingCallable<String, String> callable =
-        GrpcCallableFactory.createServerStreamingCallable(
-            grpcCallSettings,
-            serverStreamingCallSettings,
-            ClientContext.newBuilder().setDefaultCallContext(context).build());
-
-    try {
-      callable.call("Is your refrigerator running?");
-    } catch (ApiException e) {
-    }
-
-    Mockito.verify(managedChannel, times(1))
-        .newCall(ArgumentMatchers.eq(methodDescriptor), callOptionsArgumentCaptor.capture());
-    return callOptionsArgumentCaptor.getValue();
-  }
-
-  /**
-   * Compatibility wrapper for Duration's toSecondsPart, which is not supported before Java 9. This
-   * codebase must continue to support Java 7 and up, in alignment with client libraries that depend
-   * on gax-java.
-   */
-  private int toSecondsPart(Duration duration) {
-    return (int)
-        (duration.getSeconds()
-            - TimeUnit.MINUTES.toSeconds(1)
-                * (int) Math.floor(duration.getSeconds() / TimeUnit.MINUTES.toSeconds(1)));
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeChannelFactory.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeChannelFactory.java
deleted file mode 100644
index 5a98d23d0..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeChannelFactory.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.gax.grpc.ChannelFactory;
-import com.google.api.gax.grpc.ChannelPrimer;
-import io.grpc.ManagedChannel;
-import java.util.List;
-
-public class FakeChannelFactory implements ChannelFactory {
-  private int called = 0;
-  private List<ManagedChannel> channels;
-  private ChannelPrimer channelPrimer;
-
-  public FakeChannelFactory(List<ManagedChannel> channels) {
-    this.channels = channels;
-  }
-
-  public FakeChannelFactory(List<ManagedChannel> channels, ChannelPrimer channelPrimer) {
-    this.channels = channels;
-    this.channelPrimer = channelPrimer;
-  }
-
-  public ManagedChannel createSingleChannel() {
-    ManagedChannel managedChannel = channels.get(called++);
-    if (this.channelPrimer != null) {
-      this.channelPrimer.primeChannel(managedChannel);
-    }
-    return managedChannel;
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeMethodDescriptor.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeMethodDescriptor.java
deleted file mode 100644
index 0aca65ecf..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeMethodDescriptor.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import io.grpc.MethodDescriptor;
-import java.io.InputStream;
-
-@BetaApi
-public class FakeMethodDescriptor {
-  // Utility class, uninstantiable.
-  private FakeMethodDescriptor() {}
-
-  public static <I, O> MethodDescriptor<I, O> create() {
-    return create(MethodDescriptor.MethodType.UNARY, "FakeClient/fake-method");
-  }
-
-  public static <I, O> MethodDescriptor<I, O> create(
-      MethodDescriptor.MethodType type, String name) {
-    return MethodDescriptor.<I, O>newBuilder()
-        .setType(MethodDescriptor.MethodType.UNARY)
-        .setFullMethodName(name)
-        .setRequestMarshaller(new FakeMarshaller<I>())
-        .setResponseMarshaller(new FakeMarshaller<O>())
-        .build();
-  }
-
-  private static class FakeMarshaller<T> implements MethodDescriptor.Marshaller<T> {
-    @Override
-    public T parse(InputStream stream) {
-      throw new UnsupportedOperationException("FakeMarshaller doesn't actually do anything");
-    }
-
-    @Override
-    public InputStream stream(T value) {
-      throw new UnsupportedOperationException("FakeMarshaller doesn't actually do anything");
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceGrpc.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceGrpc.java
deleted file mode 100644
index 20b8564d8..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceGrpc.java
+++ /dev/null
@@ -1,268 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import static io.grpc.MethodDescriptor.generateFullMethodName;
-import static io.grpc.stub.ServerCalls.asyncBidiStreamingCall;
-import static io.grpc.stub.ServerCalls.asyncClientStreamingCall;
-import static io.grpc.stub.ServerCalls.asyncServerStreamingCall;
-import static io.grpc.stub.ServerCalls.asyncUnaryCall;
-import static io.grpc.stub.ServerCalls.asyncUnimplementedStreamingCall;
-import static io.grpc.stub.ServerCalls.asyncUnimplementedUnaryCall;
-
-import com.google.api.core.BetaApi;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.BindableService;
-import io.grpc.MethodDescriptor;
-import io.grpc.ServerServiceDefinition;
-import io.grpc.ServiceDescriptor;
-import io.grpc.protobuf.ProtoFileDescriptorSupplier;
-import io.grpc.protobuf.ProtoUtils;
-import io.grpc.stub.ServerCalls.BidiStreamingMethod;
-import io.grpc.stub.ServerCalls.ClientStreamingMethod;
-import io.grpc.stub.ServerCalls.ServerStreamingMethod;
-import io.grpc.stub.ServerCalls.UnaryMethod;
-import io.grpc.stub.StreamObserver;
-
-/**
- * This is a manually-written grpc stub class that mirrors the same structure generated by grpc from
- * proto declarations.
- */
-@BetaApi
-public final class FakeServiceGrpc {
-
-  private FakeServiceGrpc() {}
-
-  public static final String SERVICE_NAME = "google.gax.FakeService";
-
-  public static final MethodDescriptor<Color, Money> METHOD_RECOGNIZE =
-      MethodDescriptor.<Color, Money>newBuilder()
-          .setType(MethodDescriptor.MethodType.UNARY)
-          .setFullMethodName(generateFullMethodName("google.gax.FakeService", "Recognize"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Money.getDefaultInstance()))
-          .build();
-
-  public static final MethodDescriptor<Color, Operation> METHOD_LONG_RUNNING_RECOGNIZE =
-      MethodDescriptor.<Color, Operation>newBuilder()
-          .setType(MethodDescriptor.MethodType.UNARY)
-          .setFullMethodName(
-              generateFullMethodName("google.gax.FakeService", "LongRunningRecognize"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Operation.getDefaultInstance()))
-          .build();
-
-  public static final MethodDescriptor<Color, Money> METHOD_STREAMING_RECOGNIZE =
-      MethodDescriptor.<Color, Money>newBuilder()
-          .setType(MethodDescriptor.MethodType.BIDI_STREAMING)
-          .setFullMethodName(generateFullMethodName("google.gax.FakeService", "StreamingRecognize"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Money.getDefaultInstance()))
-          .build();
-
-  public static final MethodDescriptor<Color, Money> METHOD_STREAMING_RECOGNIZE_ERROR =
-      MethodDescriptor.<Color, Money>newBuilder()
-          .setType(MethodDescriptor.MethodType.BIDI_STREAMING)
-          .setFullMethodName(
-              generateFullMethodName("google.gax.FakeService", "StreamingRecognizeError"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Money.getDefaultInstance()))
-          .build();
-
-  public static final MethodDescriptor<Color, Money> METHOD_SERVER_STREAMING_RECOGNIZE =
-      MethodDescriptor.<Color, Money>newBuilder()
-          .setType(MethodDescriptor.MethodType.SERVER_STREAMING)
-          .setFullMethodName(
-              generateFullMethodName("google.gax.FakeService", "ServerStreamingRecognize"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Money.getDefaultInstance()))
-          .build();
-
-  public static final MethodDescriptor<Color, Money> METHOD_CLIENT_STREAMING_RECOGNIZE =
-      MethodDescriptor.<Color, Money>newBuilder()
-          .setType(MethodDescriptor.MethodType.CLIENT_STREAMING)
-          .setFullMethodName(
-              generateFullMethodName("google.gax.FakeService", "ClientStreamingRecognize"))
-          .setRequestMarshaller(ProtoUtils.marshaller(Color.getDefaultInstance()))
-          .setResponseMarshaller(ProtoUtils.marshaller(Money.getDefaultInstance()))
-          .build();
-
-  public abstract static class FakeServiceImplBase implements BindableService {
-
-    public void recognize(Color request, StreamObserver<Money> responseObserver) {
-      asyncUnimplementedUnaryCall(METHOD_RECOGNIZE, responseObserver);
-    }
-
-    public void longRunningRecognize(Color request, StreamObserver<Operation> responseObserver) {
-      asyncUnimplementedUnaryCall(METHOD_LONG_RUNNING_RECOGNIZE, responseObserver);
-    }
-
-    public StreamObserver<Color> streamingRecognize(StreamObserver<Money> responseObserver) {
-      return asyncUnimplementedStreamingCall(METHOD_STREAMING_RECOGNIZE, responseObserver);
-    }
-
-    public StreamObserver<Color> streamingRecognizeError(StreamObserver<Money> responseObserver) {
-      return asyncUnimplementedStreamingCall(METHOD_STREAMING_RECOGNIZE_ERROR, responseObserver);
-    }
-
-    public void serverStreamingRecognize(Color request, StreamObserver<Money> responseObserver) {
-      asyncUnimplementedUnaryCall(METHOD_SERVER_STREAMING_RECOGNIZE, responseObserver);
-    }
-
-    public StreamObserver<Color> clientStreamingRecognize(StreamObserver<Money> responseObserver) {
-      return asyncUnimplementedStreamingCall(METHOD_CLIENT_STREAMING_RECOGNIZE, responseObserver);
-    }
-
-    @Override
-    public final ServerServiceDefinition bindService() {
-      return ServerServiceDefinition.builder(getServiceDescriptor())
-          .addMethod(
-              METHOD_RECOGNIZE,
-              asyncUnaryCall(new MethodHandlers<Color, Money>(this, METHODID_RECOGNIZE)))
-          .addMethod(
-              METHOD_LONG_RUNNING_RECOGNIZE,
-              asyncUnaryCall(
-                  new MethodHandlers<Color, Operation>(this, METHODID_LONG_RUNNING_RECOGNIZE)))
-          .addMethod(
-              METHOD_STREAMING_RECOGNIZE,
-              asyncBidiStreamingCall(
-                  new MethodHandlers<Color, Money>(this, METHODID_STREAMING_RECOGNIZE)))
-          .addMethod(
-              METHOD_STREAMING_RECOGNIZE_ERROR,
-              asyncBidiStreamingCall(
-                  new MethodHandlers<Color, Money>(this, METHODID_STREAMING_RECOGNIZE_ERROR)))
-          .addMethod(
-              METHOD_SERVER_STREAMING_RECOGNIZE,
-              asyncServerStreamingCall(
-                  new MethodHandlers<Color, Money>(this, METHODID_SERVER_STREAMING_RECOGNIZE)))
-          .addMethod(
-              METHOD_CLIENT_STREAMING_RECOGNIZE,
-              asyncClientStreamingCall(
-                  new MethodHandlers<Color, Money>(this, METHODID_CLIENT_STREAMING_RECOGNIZE)))
-          .build();
-    }
-  }
-
-  private static final int METHODID_RECOGNIZE = 0;
-  private static final int METHODID_LONG_RUNNING_RECOGNIZE = 1;
-  private static final int METHODID_STREAMING_RECOGNIZE = 2;
-  private static final int METHODID_STREAMING_RECOGNIZE_ERROR = 3;
-  private static final int METHODID_SERVER_STREAMING_RECOGNIZE = 4;
-  private static final int METHODID_CLIENT_STREAMING_RECOGNIZE = 5;
-
-  private static final class MethodHandlers<Req, Resp>
-      implements UnaryMethod<Req, Resp>,
-          ServerStreamingMethod<Req, Resp>,
-          ClientStreamingMethod<Req, Resp>,
-          BidiStreamingMethod<Req, Resp> {
-
-    private final FakeServiceImplBase serviceImpl;
-    private final int methodId;
-
-    MethodHandlers(FakeServiceImplBase serviceImpl, int methodId) {
-      this.serviceImpl = serviceImpl;
-      this.methodId = methodId;
-    }
-
-    @Override
-    @SuppressWarnings("unchecked")
-    public void invoke(Req request, StreamObserver<Resp> responseObserver) {
-      switch (methodId) {
-        case METHODID_RECOGNIZE:
-          serviceImpl.recognize((Color) request, (StreamObserver<Money>) responseObserver);
-          break;
-        case METHODID_LONG_RUNNING_RECOGNIZE:
-          serviceImpl.longRunningRecognize(
-              (Color) request, (StreamObserver<Operation>) responseObserver);
-          break;
-        case METHODID_SERVER_STREAMING_RECOGNIZE:
-          serviceImpl.serverStreamingRecognize(
-              (Color) request, (StreamObserver<Money>) responseObserver);
-          break;
-        default:
-          throw new AssertionError();
-      }
-    }
-
-    @Override
-    @SuppressWarnings("unchecked")
-    public StreamObserver<Req> invoke(StreamObserver<Resp> responseObserver) {
-      switch (methodId) {
-        case METHODID_STREAMING_RECOGNIZE:
-          return (StreamObserver<Req>)
-              serviceImpl.streamingRecognize((StreamObserver<Money>) responseObserver);
-        case METHODID_STREAMING_RECOGNIZE_ERROR:
-          return (StreamObserver<Req>)
-              serviceImpl.streamingRecognizeError((StreamObserver<Money>) responseObserver);
-        case METHODID_CLIENT_STREAMING_RECOGNIZE:
-          return (StreamObserver<Req>)
-              serviceImpl.clientStreamingRecognize((StreamObserver<Money>) responseObserver);
-        default:
-          throw new AssertionError();
-      }
-    }
-  }
-
-  private static final class FakeServiceDescriptorSupplier implements ProtoFileDescriptorSupplier {
-
-    @Override
-    public FileDescriptor getFileDescriptor() {
-      return null;
-    }
-  }
-
-  private static volatile ServiceDescriptor serviceDescriptor;
-
-  public static ServiceDescriptor getServiceDescriptor() {
-    ServiceDescriptor result = serviceDescriptor;
-    if (result == null) {
-      synchronized (FakeServiceGrpc.class) {
-        result = serviceDescriptor;
-        if (result == null) {
-          serviceDescriptor =
-              result =
-                  ServiceDescriptor.newBuilder(SERVICE_NAME)
-                      .setSchemaDescriptor(new FakeServiceDescriptorSupplier())
-                      .addMethod(METHOD_RECOGNIZE)
-                      .addMethod(METHOD_LONG_RUNNING_RECOGNIZE)
-                      .addMethod(METHOD_STREAMING_RECOGNIZE)
-                      .addMethod(METHOD_STREAMING_RECOGNIZE_ERROR)
-                      .addMethod(METHOD_SERVER_STREAMING_RECOGNIZE)
-                      .addMethod(METHOD_CLIENT_STREAMING_RECOGNIZE)
-                      .build();
-        }
-      }
-    }
-    return result;
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceImpl.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceImpl.java
deleted file mode 100644
index 298e84783..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/FakeServiceImpl.java
+++ /dev/null
@@ -1,137 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.grpc.testing.FakeServiceGrpc.FakeServiceImplBase;
-import com.google.type.Color;
-import com.google.type.Money;
-import io.grpc.Status;
-import io.grpc.StatusRuntimeException;
-import io.grpc.stub.StreamObserver;
-
-@BetaApi
-public class FakeServiceImpl extends FakeServiceImplBase {
-  private Throwable receivedError;
-
-  public Throwable getLastRecievedError() {
-    return receivedError;
-  }
-
-  @Override
-  public StreamObserver<Color> streamingRecognize(StreamObserver<Money> responseObserver) {
-    return new RequestStreamObserver(responseObserver);
-  }
-
-  public StreamObserver<Color> streamingRecognizeError(
-      final StreamObserver<Money> responseObserver) {
-    return new StreamObserver<Color>() {
-      @Override
-      public void onNext(Color color) {
-        responseObserver.onError(new StatusRuntimeException(Status.INVALID_ARGUMENT));
-      }
-
-      @Override
-      public void onError(Throwable throwable) {
-        receivedError = throwable;
-      }
-
-      @Override
-      public void onCompleted() {}
-    };
-  }
-
-  @Override
-  public void serverStreamingRecognize(
-      final Color color, final StreamObserver<Money> responseObserver) {
-    if (color.getRed() < 0) {
-      responseObserver.onError(
-          Status.INVALID_ARGUMENT.withDescription("red must be positive").asRuntimeException());
-      return;
-    }
-
-    // Defer the execution using the green channel. This is necessary when testing cancellation,
-    // because the InProcessServer uses a direct executor and will buffer the results ignoring
-    // cancellation
-    Runnable runnable =
-        new Runnable() {
-          @Override
-          public void run() {
-            try {
-              Thread.sleep((long) color.getGreen());
-            } catch (InterruptedException e) {
-              Thread.interrupted();
-              return;
-            }
-            responseObserver.onNext(convert(color));
-            responseObserver.onCompleted();
-          }
-        };
-
-    if (color.getGreen() > 0) {
-      new Thread(runnable).start();
-    } else {
-      runnable.run();
-    }
-  }
-
-  public StreamObserver<Color> clientStreamingRecognize(StreamObserver<Money> responseObserver) {
-    return new RequestStreamObserver(responseObserver);
-  }
-
-  private static Money convert(Color color) {
-    Money result =
-        Money.newBuilder().setCurrencyCode("USD").setUnits((long) (color.getRed() * 255)).build();
-    return result;
-  }
-
-  private static class RequestStreamObserver implements StreamObserver<Color> {
-    private StreamObserver<Money> responseObserver;
-
-    public RequestStreamObserver(StreamObserver<Money> responseObserver) {
-      this.responseObserver = responseObserver;
-    }
-
-    @Override
-    public void onNext(Color color) {
-      responseObserver.onNext(convert(color));
-    }
-
-    @Override
-    public void onError(Throwable throwable) {
-      throwable.printStackTrace(System.err);
-    }
-
-    @Override
-    public void onCompleted() {
-      responseObserver.onCompleted();
-    }
-  };
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/InProcessServer.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/InProcessServer.java
deleted file mode 100644
index d93495aa8..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/InProcessServer.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import io.grpc.BindableService;
-import io.grpc.Metadata;
-import io.grpc.Server;
-import io.grpc.ServerCall;
-import io.grpc.ServerCall.Listener;
-import io.grpc.ServerCallHandler;
-import io.grpc.ServerInterceptor;
-import io.grpc.inprocess.InProcessServerBuilder;
-import java.io.IOException;
-
-@BetaApi
-public class InProcessServer<T extends BindableService> {
-  private T serverImpl;
-  private String name;
-  private ServerInterceptor interceptor;
-
-  private Server server;
-
-  public InProcessServer(T serverImpl, String name) {
-    this(
-        serverImpl,
-        name,
-        new ServerInterceptor() {
-          @Override
-          public <ReqT, RespT> Listener<ReqT> interceptCall(
-              ServerCall<ReqT, RespT> call, Metadata headers, ServerCallHandler<ReqT, RespT> next) {
-            return next.startCall(call, headers);
-          }
-        });
-  }
-
-  public InProcessServer(T serverImpl, String name, ServerInterceptor interceptor) {
-    this.serverImpl = serverImpl;
-    this.name = name;
-    this.interceptor = interceptor;
-  }
-
-  public void start() throws IOException, InstantiationException, IllegalAccessException {
-    server =
-        InProcessServerBuilder.forName(name)
-            .directExecutor()
-            .addService(serverImpl)
-            .intercept(interceptor)
-            .build()
-            .start();
-    Runtime.getRuntime()
-        .addShutdownHook(
-            new Thread() {
-              @Override
-              public void run() {
-                InProcessServer.this.stop();
-              }
-            });
-  }
-
-  public void stop() {
-    if (server != null) {
-      server.shutdown();
-    }
-  }
-
-  public void blockUntilShutdown() throws InterruptedException {
-    if (server != null) {
-      server.awaitTermination();
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/LocalChannelProvider.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/LocalChannelProvider.java
deleted file mode 100644
index 5e538a06c..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/LocalChannelProvider.java
+++ /dev/null
@@ -1,206 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.grpc.GrpcHeaderInterceptor;
-import com.google.api.gax.grpc.GrpcTransportChannel;
-import com.google.api.gax.rpc.FixedHeaderProvider;
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.auth.Credentials;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.ForwardingClientCall.SimpleForwardingClientCall;
-import io.grpc.ManagedChannelBuilder;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.inprocess.InProcessChannelBuilder;
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.regex.Pattern;
-
-/** LocalChannelProvider creates channels for in-memory gRPC services. */
-@BetaApi
-public class LocalChannelProvider implements TransportChannelProvider {
-
-  private final List<LocalHeaderInterceptor> interceptors;
-  private final String address;
-
-  private volatile HeaderProvider headerProvider;
-
-  private LocalChannelProvider(String address, HeaderProvider headerProvider) {
-    this.interceptors = new CopyOnWriteArrayList<>();
-    this.address = address;
-    this.headerProvider = headerProvider;
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return true;
-  }
-
-  @Deprecated
-  @Override
-  public boolean needsExecutor() {
-    return false;
-  }
-
-  @Deprecated
-  @Override
-  public TransportChannelProvider withExecutor(ScheduledExecutorService executor) {
-    return withExecutor((Executor) executor);
-  }
-
-  @Override
-  public TransportChannelProvider withExecutor(Executor executor) {
-    throw new UnsupportedOperationException("LocalChannelProvider doesn't need an executor");
-  }
-
-  @Override
-  public boolean needsHeaders() {
-    return headerProvider == null;
-  }
-
-  @Override
-  public boolean needsEndpoint() {
-    return false;
-  }
-
-  @Override
-  public TransportChannelProvider withEndpoint(String endpoint) {
-    throw new UnsupportedOperationException("LocalChannelProvider doesn't need an endpoint");
-  }
-
-  @Override
-  @BetaApi("The surface for customizing pool size is not stable yet and may change in the future.")
-  public boolean acceptsPoolSize() {
-    return false;
-  }
-
-  @Override
-  @BetaApi("The surface for customizing pool size is not stable yet and may change in the future.")
-  public TransportChannelProvider withPoolSize(int size) {
-    throw new UnsupportedOperationException(
-        "LocalChannelProvider doesn't allow pool size customization");
-  }
-
-  @Override
-  public TransportChannelProvider withHeaders(Map<String, String> headers) {
-    this.headerProvider = FixedHeaderProvider.create(headers);
-    return this;
-  }
-
-  @Override
-  public TransportChannel getTransportChannel() throws IOException {
-    ManagedChannelBuilder channelBuilder = InProcessChannelBuilder.forName(address).usePlaintext();
-    if (headerProvider != null) {
-      GrpcHeaderInterceptor interceptor = new GrpcHeaderInterceptor(headerProvider.getHeaders());
-      LocalHeaderInterceptor localHeaderInterceptor = new LocalHeaderInterceptor(interceptor);
-      interceptors.add(localHeaderInterceptor);
-      channelBuilder.intercept(localHeaderInterceptor).userAgent(interceptor.getUserAgentHeader());
-    }
-    return GrpcTransportChannel.newBuilder().setManagedChannel(channelBuilder.build()).build();
-  }
-
-  @Override
-  public String getTransportName() {
-    return GrpcTransportChannel.getGrpcTransportName();
-  }
-
-  @Override
-  public boolean needsCredentials() {
-    return false;
-  }
-
-  @Override
-  public TransportChannelProvider withCredentials(Credentials credentials) {
-    throw new UnsupportedOperationException("LocalChannelProvider doesn't need credentials");
-  }
-
-  /** Creates a LocalChannelProvider. */
-  public static LocalChannelProvider create(String addressString) {
-    return new LocalChannelProvider(addressString, null);
-  }
-
-  public boolean isHeaderSent(String headerKey, Pattern headerPattern) {
-    Metadata.Key<String> key = Metadata.Key.of(headerKey, Metadata.ASCII_STRING_MARSHALLER);
-
-    if (interceptors.isEmpty()) {
-      return false;
-    }
-    for (LocalHeaderInterceptor interceptor : interceptors) {
-      if (interceptor.getSubmittedHeaders().isEmpty()) {
-        return false;
-      }
-      for (Metadata submittedHeaders : interceptor.getSubmittedHeaders()) {
-        String headerValue = submittedHeaders.get(key);
-        if (headerValue == null || !headerPattern.matcher(headerValue).matches()) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  private static class LocalHeaderInterceptor implements ClientInterceptor {
-    private final ClientInterceptor innerInterceptor;
-    private final List<Metadata> submittedHeaders;
-
-    private LocalHeaderInterceptor(ClientInterceptor innerInterceptor) {
-      this.innerInterceptor = innerInterceptor;
-      this.submittedHeaders = new CopyOnWriteArrayList<>();
-    }
-
-    @Override
-    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
-        MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
-      ClientCall<ReqT, RespT> call = innerInterceptor.interceptCall(method, callOptions, next);
-      return new SimpleForwardingClientCall<ReqT, RespT>(call) {
-        @Override
-        public void start(Listener<RespT> responseListener, Metadata headers) {
-          super.start(responseListener, headers);
-          submittedHeaders.add(headers);
-        }
-      };
-    }
-
-    List<Metadata> getSubmittedHeaders() {
-      return submittedHeaders;
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockGrpcService.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockGrpcService.java
deleted file mode 100644
index 237760913..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockGrpcService.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.protobuf.AbstractMessage;
-import io.grpc.ServerServiceDefinition;
-import java.util.List;
-
-/** An interface of mock gRPC service. */
-@BetaApi
-public interface MockGrpcService {
-  /** Returns all the requests received. */
-  List<AbstractMessage> getRequests();
-
-  /** Adds the response to the response queue. */
-  void addResponse(AbstractMessage response);
-
-  /** Adds the exception to the response queue. */
-  void addException(Exception exception);
-
-  /** Returns gRPC service definition used for binding. */
-  ServerServiceDefinition getServiceDefinition();
-
-  /** Resets the state. */
-  void reset();
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelper.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelper.java
deleted file mode 100644
index 9f763b0f5..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelper.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.Lists;
-import io.grpc.Server;
-import io.grpc.inprocess.InProcessServerBuilder;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-
-/** A utility class to control a local service which is used by testing. */
-@BetaApi
-public class MockServiceHelper {
-  private static final int FLOW_CONTROL_WINDOW = 65 * 1024;
-
-  private final String addressString;
-  private final Server server;
-  private final List<MockGrpcService> mockServices;
-
-  /** Constructs a new MockServiceHelper. The method start() must be called before it is used. */
-  public MockServiceHelper(String addressString, MockGrpcService mockService) {
-    this(addressString, Arrays.asList(mockService));
-  }
-
-  public MockServiceHelper(String addressString, List<MockGrpcService> mockServices) {
-    this.addressString = addressString;
-    this.mockServices = Lists.newArrayList(mockServices);
-    InProcessServerBuilder builder = InProcessServerBuilder.forName(addressString);
-    for (MockGrpcService mockService : mockServices) {
-      builder.addService(mockService.getServiceDefinition());
-    }
-    this.server = builder.build();
-  }
-
-  @VisibleForTesting
-  MockServiceHelper(Server server, String address, MockGrpcService mockService) {
-    this(server, address, Arrays.asList(mockService));
-  }
-
-  @VisibleForTesting
-  MockServiceHelper(Server server, String addressString, List<MockGrpcService> mockServices) {
-    this.server = server;
-    this.addressString = addressString;
-    this.mockServices = mockServices;
-  }
-
-  /** Starts the local server. */
-  public void start() {
-    try {
-      server.start();
-    } catch (IOException ex) {
-      throw new RuntimeException(ex);
-    }
-  }
-
-  /** Resets the state of the mock service. */
-  public void reset() {
-    for (MockGrpcService mockService : mockServices) {
-      mockService.reset();
-    }
-  }
-
-  /** Stops the local server. */
-  public void stop() {
-    server.shutdownNow();
-  }
-
-  /** Returns the mock grpc service. */
-  public MockGrpcService getService() {
-    if (mockServices.size() != 1) {
-      throw new IllegalStateException(
-          "MockServiceHelper.getService() can only be called if "
-              + "there is one service, but there are "
-              + mockServices.size());
-    }
-    return mockServices.get(0);
-  }
-
-  /** Returns all of the mocked grpc services. */
-  public List<MockGrpcService> getServices() {
-    return mockServices;
-  }
-
-  /** Creates a channel for making requests to the mock service. */
-  public LocalChannelProvider createChannelProvider() {
-    return LocalChannelProvider.create(addressString);
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelperTest.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelperTest.java
deleted file mode 100644
index 585f8ec65..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockServiceHelperTest.java
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.common.truth.Truth;
-import io.grpc.Server;
-import io.grpc.ServerServiceDefinition;
-import java.io.IOException;
-import java.util.Arrays;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.MockitoAnnotations;
-
-/** Tests for {@link MockServiceHelper}. */
-@RunWith(JUnit4.class)
-public class MockServiceHelperTest {
-  @Mock private MockGrpcService grpcService;
-  @Mock private MockGrpcService grpcService2;
-
-  @Mock private Server server;
-
-  /** Sets up mocks. */
-  @Before
-  public void setUp() {
-    MockitoAnnotations.initMocks(this);
-    when(grpcService.getServiceDefinition())
-        .thenReturn(ServerServiceDefinition.builder("fake-service").build());
-    when(grpcService2.getServiceDefinition())
-        .thenReturn(ServerServiceDefinition.builder("fake-service2").build());
-  }
-
-  @Test
-  public void testGetService() {
-    MockServiceHelper serviceHelper = new MockServiceHelper(server, "fake-address", grpcService);
-    Truth.assertThat(serviceHelper.getService()).isSameInstanceAs(grpcService);
-    Truth.assertThat(serviceHelper.getServices().size()).isEqualTo(1);
-  }
-
-  @Test(expected = IllegalStateException.class)
-  public void testGetServiceInvalid() {
-    MockServiceHelper serviceHelper =
-        new MockServiceHelper(server, "fake-address2", Arrays.asList(grpcService, grpcService2));
-    serviceHelper.getService();
-  }
-
-  @Test
-  public void testStart() throws IOException {
-    MockServiceHelper serviceHelper = new MockServiceHelper(server, "fake-address", grpcService);
-    serviceHelper.start();
-    verify(server, times(1)).start();
-  }
-
-  @Test
-  public void testReset() {
-    MockServiceHelper serviceHelper = new MockServiceHelper("fake-address", grpcService);
-    serviceHelper.reset();
-    verify(grpcService, times(1)).getServiceDefinition();
-    verify(grpcService, times(1)).reset();
-  }
-
-  @Test
-  public void testCreateChannelProvider() throws Exception {
-    MockServiceHelper serviceHelper = new MockServiceHelper("fake-address", grpcService);
-    TransportChannel channel = serviceHelper.createChannelProvider().getTransportChannel();
-    assertNotNull(channel);
-    assertFalse(channel.isTerminated());
-    channel.shutdownNow();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockStreamObserver.java b/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockStreamObserver.java
deleted file mode 100644
index ce86cff5a..000000000
--- a/gax-grpc/src/test/java/com/google/api/gax/grpc/testing/MockStreamObserver.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.grpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import java.util.ArrayList;
-import java.util.List;
-
-/** An implementation of ApiStreamObserver used by testing. */
-@BetaApi
-public class MockStreamObserver<T> implements ApiStreamObserver<T> {
-
-  private final SettableApiFuture<List<T>> future = SettableApiFuture.create();
-  private final List<T> actualMessages = new ArrayList<>();
-
-  @Override
-  public void onNext(T message) {
-    actualMessages.add(message);
-  }
-
-  @Override
-  public void onError(Throwable t) {
-    future.setException(t);
-  }
-
-  @Override
-  public void onCompleted() {
-    future.set(actualMessages);
-  }
-  // Returns the SettableFuture object which can be used to retrieve received messages.
-  public SettableApiFuture<List<T>> future() {
-    return future;
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/longrunning/MockOperations.java b/gax-grpc/src/test/java/com/google/longrunning/MockOperations.java
deleted file mode 100644
index 624eaa5c6..000000000
--- a/gax-grpc/src/test/java/com/google/longrunning/MockOperations.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.grpc.testing.MockGrpcService;
-import com.google.protobuf.AbstractMessage;
-import io.grpc.ServerServiceDefinition;
-import java.util.List;
-
-@BetaApi
-public class MockOperations implements MockGrpcService {
-  private final MockOperationsImpl serviceImpl;
-
-  public MockOperations() {
-    serviceImpl = new MockOperationsImpl();
-  }
-
-  @Override
-  public List<AbstractMessage> getRequests() {
-    return serviceImpl.getRequests();
-  }
-
-  @Override
-  public void addResponse(AbstractMessage response) {
-    serviceImpl.addResponse(response);
-  }
-
-  @Override
-  public void addException(Exception exception) {
-    serviceImpl.addException(exception);
-  }
-
-  @Override
-  public ServerServiceDefinition getServiceDefinition() {
-    return serviceImpl.bindService();
-  }
-
-  @Override
-  public void reset() {
-    serviceImpl.reset();
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/longrunning/MockOperationsImpl.java b/gax-grpc/src/test/java/com/google/longrunning/MockOperationsImpl.java
deleted file mode 100644
index 594508d3d..000000000
--- a/gax-grpc/src/test/java/com/google/longrunning/MockOperationsImpl.java
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning;
-
-import com.google.api.core.BetaApi;
-import com.google.longrunning.OperationsGrpc.OperationsImplBase;
-import com.google.protobuf.AbstractMessage;
-import com.google.protobuf.Empty;
-import io.grpc.stub.StreamObserver;
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-@BetaApi
-public class MockOperationsImpl extends OperationsImplBase {
-  private List<AbstractMessage> requests;
-  private Queue<Object> responses;
-
-  public MockOperationsImpl() {
-    requests = new ArrayList<>();
-    responses = new LinkedList<>();
-  }
-
-  public List<AbstractMessage> getRequests() {
-    return requests;
-  }
-
-  public void addResponse(AbstractMessage response) {
-    responses.add(response);
-  }
-
-  public void setResponses(List<AbstractMessage> responses) {
-    this.responses = new LinkedList<Object>(responses);
-  }
-
-  public void addException(Exception exception) {
-    responses.add(exception);
-  }
-
-  public void reset() {
-    requests = new ArrayList<>();
-    responses = new LinkedList<>();
-  }
-
-  @Override
-  public void listOperations(
-      ListOperationsRequest request, StreamObserver<ListOperationsResponse> responseObserver) {
-    Object response = responses.remove();
-    if (response instanceof ListOperationsResponse) {
-      requests.add(request);
-      responseObserver.onNext((ListOperationsResponse) response);
-      responseObserver.onCompleted();
-    } else if (response instanceof Exception) {
-      responseObserver.onError((Exception) response);
-    } else {
-      responseObserver.onError(new IllegalArgumentException("Unrecognized response type"));
-    }
-  }
-
-  @Override
-  public void getOperation(
-      GetOperationRequest request, StreamObserver<Operation> responseObserver) {
-    Object response = responses.remove();
-    if (response instanceof Operation) {
-      requests.add(request);
-      responseObserver.onNext((Operation) response);
-      responseObserver.onCompleted();
-    } else if (response instanceof Exception) {
-      responseObserver.onError((Exception) response);
-    } else {
-      responseObserver.onError(new IllegalArgumentException("Unrecognized response type"));
-    }
-  }
-
-  @Override
-  public void deleteOperation(
-      DeleteOperationRequest request, StreamObserver<Empty> responseObserver) {
-    Object response = responses.remove();
-    if (response instanceof Empty) {
-      requests.add(request);
-      responseObserver.onNext((Empty) response);
-      responseObserver.onCompleted();
-    } else if (response instanceof Exception) {
-      responseObserver.onError((Exception) response);
-    } else {
-      responseObserver.onError(new IllegalArgumentException("Unrecognized response type"));
-    }
-  }
-
-  @Override
-  public void cancelOperation(
-      CancelOperationRequest request, StreamObserver<Empty> responseObserver) {
-    Object response = responses.remove();
-    if (response instanceof Empty) {
-      requests.add(request);
-      responseObserver.onNext((Empty) response);
-      responseObserver.onCompleted();
-    } else if (response instanceof Exception) {
-      responseObserver.onError((Exception) response);
-    } else {
-      responseObserver.onError(new IllegalArgumentException("Unrecognized response type"));
-    }
-  }
-
-  @Override
-  public void waitOperation(
-      WaitOperationRequest request, StreamObserver<Operation> responseObserver) {
-    Object response = responses.remove();
-    if (response instanceof Operation) {
-      requests.add(request);
-      responseObserver.onNext((Operation) response);
-      responseObserver.onCompleted();
-    } else if (response instanceof Exception) {
-      responseObserver.onError((Exception) response);
-    } else {
-      responseObserver.onError(
-          new IllegalArgumentException(
-              String.format(
-                  "Unrecognized response type %s, expected %s or %s",
-                  response.getClass().getName(),
-                  Operation.class.getName(),
-                  Exception.class.getName())));
-    }
-  }
-}
diff --git a/gax-grpc/src/test/java/com/google/longrunning/OperationsClientTest.java b/gax-grpc/src/test/java/com/google/longrunning/OperationsClientTest.java
deleted file mode 100644
index 0c5eaa302..000000000
--- a/gax-grpc/src/test/java/com/google/longrunning/OperationsClientTest.java
+++ /dev/null
@@ -1,280 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.longrunning;
-
-import com.google.api.gax.core.NoCredentialsProvider;
-import com.google.api.gax.grpc.testing.LocalChannelProvider;
-import com.google.api.gax.grpc.testing.MockGrpcService;
-import com.google.api.gax.grpc.testing.MockServiceHelper;
-import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.common.collect.Lists;
-import com.google.longrunning.OperationsClient.ListOperationsPagedResponse;
-import com.google.protobuf.AbstractMessage;
-import com.google.protobuf.Duration;
-import com.google.protobuf.Empty;
-import io.grpc.Status;
-import io.grpc.StatusRuntimeException;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.BeforeClass;
-import org.junit.Test;
-
-public class OperationsClientTest {
-  private static MockOperations mockOperations;
-  private static MockServiceHelper serviceHelper;
-  private OperationsClient client;
-  private LocalChannelProvider channelProvider;
-
-  @BeforeClass
-  public static void startStaticServer() {
-    mockOperations = new MockOperations();
-    serviceHelper =
-        new MockServiceHelper("in-process-1", Arrays.<MockGrpcService>asList(mockOperations));
-    serviceHelper.start();
-  }
-
-  @AfterClass
-  public static void stopServer() {
-    serviceHelper.stop();
-  }
-
-  @Before
-  public void setUp() throws IOException {
-    serviceHelper.reset();
-    channelProvider = serviceHelper.createChannelProvider();
-    OperationsSettings settings =
-        OperationsSettings.newBuilder()
-            .setTransportChannelProvider(channelProvider)
-            .setCredentialsProvider(NoCredentialsProvider.create())
-            .build();
-    client = OperationsClient.create(settings);
-  }
-
-  @After
-  public void tearDown() {
-    client.close();
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void getOperationTest() {
-    String name2 = "name2-1052831874";
-    boolean done = true;
-    Operation expectedResponse = Operation.newBuilder().setName(name2).setDone(done).build();
-    mockOperations.addResponse(expectedResponse);
-
-    String name = "name3373707";
-
-    Operation actualResponse = client.getOperation(name);
-    Assert.assertEquals(expectedResponse, actualResponse);
-
-    List<AbstractMessage> actualRequests = mockOperations.getRequests();
-    Assert.assertEquals(1, actualRequests.size());
-    GetOperationRequest actualRequest = (GetOperationRequest) actualRequests.get(0);
-
-    Assert.assertEquals(name, actualRequest.getName());
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void getOperationExceptionTest() throws Exception {
-    StatusRuntimeException exception = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    mockOperations.addException(exception);
-
-    try {
-      String name = "name3373707";
-
-      client.getOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception
-    }
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void listOperationsTest() {
-    String nextPageToken = "";
-    Operation operationsElement = Operation.newBuilder().build();
-    List<Operation> operations = Arrays.asList(operationsElement);
-    ListOperationsResponse expectedResponse =
-        ListOperationsResponse.newBuilder()
-            .setNextPageToken(nextPageToken)
-            .addAllOperations(operations)
-            .build();
-    mockOperations.addResponse(expectedResponse);
-
-    String name = "name3373707";
-    String filter = "filter-1274492040";
-
-    ListOperationsPagedResponse pagedListResponse = client.listOperations(name, filter);
-
-    List<Operation> resources = Lists.newArrayList(pagedListResponse.iterateAll());
-    Assert.assertEquals(1, resources.size());
-    Assert.assertEquals(expectedResponse.getOperationsList().get(0), resources.get(0));
-
-    List<AbstractMessage> actualRequests = mockOperations.getRequests();
-    Assert.assertEquals(1, actualRequests.size());
-    ListOperationsRequest actualRequest = (ListOperationsRequest) actualRequests.get(0);
-
-    Assert.assertEquals(name, actualRequest.getName());
-    Assert.assertEquals(filter, actualRequest.getFilter());
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void listOperationsExceptionTest() throws Exception {
-    StatusRuntimeException exception = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    mockOperations.addException(exception);
-
-    try {
-      String name = "name3373707";
-      String filter = "filter-1274492040";
-
-      client.listOperations(name, filter);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception
-    }
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void cancelOperationTest() {
-    Empty expectedResponse = Empty.newBuilder().build();
-    mockOperations.addResponse(expectedResponse);
-
-    String name = "name3373707";
-
-    client.cancelOperation(name);
-
-    List<AbstractMessage> actualRequests = mockOperations.getRequests();
-    Assert.assertEquals(1, actualRequests.size());
-    CancelOperationRequest actualRequest = (CancelOperationRequest) actualRequests.get(0);
-
-    Assert.assertEquals(name, actualRequest.getName());
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void cancelOperationExceptionTest() throws Exception {
-    StatusRuntimeException exception = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    mockOperations.addException(exception);
-
-    try {
-      String name = "name3373707";
-
-      client.cancelOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception
-    }
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void deleteOperationTest() {
-    Empty expectedResponse = Empty.newBuilder().build();
-    mockOperations.addResponse(expectedResponse);
-
-    String name = "name3373707";
-
-    client.deleteOperation(name);
-
-    List<AbstractMessage> actualRequests = mockOperations.getRequests();
-    Assert.assertEquals(1, actualRequests.size());
-    DeleteOperationRequest actualRequest = (DeleteOperationRequest) actualRequests.get(0);
-
-    Assert.assertEquals(name, actualRequest.getName());
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void deleteOperationExceptionTest() throws Exception {
-    StatusRuntimeException exception = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    mockOperations.addException(exception);
-
-    try {
-      String name = "name3373707";
-
-      client.deleteOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception
-    }
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void waitOperationTest() {
-    String name2 = "name2-1052831874";
-    boolean done = true;
-    Operation expectedResponse = Operation.newBuilder().setName(name2).setDone(done).build();
-    mockOperations.addResponse(expectedResponse);
-
-    String name = "name3373707";
-    Duration timeout = Duration.newBuilder().setSeconds(5).build();
-    WaitOperationRequest request =
-        WaitOperationRequest.newBuilder().setName(name).setTimeout(timeout).build();
-
-    Operation actualResponse = client.waitOperation(request);
-    Assert.assertEquals(expectedResponse, actualResponse);
-
-    List<AbstractMessage> actualRequests = mockOperations.getRequests();
-    Assert.assertEquals(1, actualRequests.size());
-    WaitOperationRequest actualRequest = (WaitOperationRequest) actualRequests.get(0);
-
-    Assert.assertEquals(name, actualRequest.getName());
-  }
-
-  @Test
-  @SuppressWarnings("all")
-  public void waitOperationExceptionTest() throws Exception {
-    StatusRuntimeException exception = new StatusRuntimeException(Status.INVALID_ARGUMENT);
-    mockOperations.addException(exception);
-
-    try {
-      String name = "name3373707";
-      Duration timeout = Duration.newBuilder().setSeconds(5).build();
-      WaitOperationRequest request =
-          WaitOperationRequest.newBuilder().setName(name).setTimeout(timeout).build();
-
-      client.waitOperation(request);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception
-    }
-  }
-}
diff --git a/gax-httpjson/BUILD.bazel b/gax-httpjson/BUILD.bazel
deleted file mode 100644
index 0ddf20181..000000000
--- a/gax-httpjson/BUILD.bazel
+++ /dev/null
@@ -1,79 +0,0 @@
-load("//:gax_java.bzl", "google_java_format", "google_java_format_verification", "java_tests")
-
-_JAVA_COPTS = [
-    "-source",
-    "1.8",
-    "-target",
-    "1.8",
-]
-
-_COMPILE_DEPS = [
-    "@com_google_code_gson_gson//jar",
-    "@com_google_guava_guava//jar",
-    "@com_google_code_findbugs_jsr305//jar",
-    "@org_threeten_threetenbp//jar",
-    "@com_google_http_client_google_http_client//jar",
-    "@com_google_auth_google_auth_library_oauth2_http//jar",
-    "@com_google_auth_google_auth_library_credentials//jar",
-    "@com_google_api_api_common//jar",
-    "@com_google_auto_value_auto_value//jar",
-    "@com_google_auto_value_auto_value_annotations//jar",
-    "@javax_annotation_javax_annotation_api//jar",
-    "@com_google_http_client_google_http_client_gson//jar",
-    "@com_google_api_grpc_proto_google_common_protos//jar",
-    "@com_google_protobuf//:protobuf_java",
-    "@com_google_protobuf_java_util//jar",
-    "//gax:gax",
-]
-
-_TEST_COMPILE_DEPS = [
-    "@junit_junit//jar",
-    "@org_mockito_mockito_core//jar",
-    "@com_google_truth_truth//jar",
-    "//gax:gax_testlib",
-    "@com_googlecode_java_diff_utils_diffutils//jar",
-]
-
-java_library(
-    name = "gax_httpjson",
-    srcs = glob(["src/main/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    resources = ["//:dependencies.properties"],
-    visibility = ["//visibility:public"],
-    deps = _COMPILE_DEPS,
-)
-
-java_library(
-    name = "gax_httpjson_testlib",
-    srcs = glob(["src/test/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    visibility = ["//visibility:public"],
-    deps = [":gax_httpjson"] + _COMPILE_DEPS + _TEST_COMPILE_DEPS,
-)
-
-java_tests(
-    name = "gax_httpjson_tests",
-    size = "small",
-    srcs = glob(
-        include = ["src/test/java/**/*Test.java"],
-        exclude = [
-            "src/test/java/**/Abstract*Test.java",
-        ],
-    ),
-    runtime_deps = [":gax_httpjson_testlib"],
-)
-
-google_java_format(
-    name = "google_java_format",
-    srcs = glob(["src/**/*.java"]),
-    formatter = "//:google_java_format_binary",
-)
-
-#Uncomment once java formatter is upgraded to 1.6+
-#google_java_format_verification(
-#    name = "google_java_format_verification",
-#    srcs = glob(["src/**/*.java"]),
-#    formatter = "//:google_java_format_binary",
-#)
diff --git a/gax-httpjson/build.gradle b/gax-httpjson/build.gradle
deleted file mode 100644
index d16bf0fed..000000000
--- a/gax-httpjson/build.gradle
+++ /dev/null
@@ -1,43 +0,0 @@
-archivesBaseName = 'gax-httpjson'
-
-// TODO: Populate this from dependencies.properties version property (for proper Gradle-Bazel sync)
-project.version = "0.105.1" // {x-version-update:gax-httpjson:current}
-
-dependencies {
-  api(project(':gax'),
-    libraries['maven.com_google_api_api_common'],
-    libraries['maven.com_google_api_grpc_proto_google_common_protos'],
-    libraries['maven.com_google_auth_google_auth_library_credentials'],
-    libraries['maven.com_google_code_gson_gson'],
-    libraries['maven.com_google_guava_guava'],
-    libraries['maven.com_google_http_client_google_http_client'],
-    libraries['maven.com_google_protobuf'],
-    libraries['maven.org_threeten_threetenbp'])
-
-  implementation(libraries['maven.com_google_auth_google_auth_library_oauth2_http'],
-    libraries['maven.com_google_code_findbugs_jsr305'],
-    libraries['maven.com_google_http_client_google_http_client_gson'],
-    libraries['maven.com_google_protobuf_java_util'])
-
-  compileOnly libraries['maven.com_google_auto_value_auto_value']
-
-  testImplementation(project(':gax').sourceSets.test.output,
-    libraries['maven.junit_junit'],
-    libraries['maven.org_mockito_mockito_core'],
-    libraries['maven.com_google_truth_truth'])
-
-  annotationProcessor libraries['maven.com_google_auto_value_auto_value']
-
-  shadowNoGuava libraries['maven.com_google_guava_guava']
-}
-
-jar {
-  manifest {
-    attributes 'Specification-Title': project.name,
-      'Specification-Version': project.version,
-      'Specification-Vendor': libraryVendor,
-      'Implementation-Title': project.name,
-      'Implementation-Version': project.version,
-      'Implementation-Vendor': libraryVendor
-  }
-}
diff --git a/gax-httpjson/pom.xml b/gax-httpjson/pom.xml
deleted file mode 100644
index 32fcdc5f1..000000000
--- a/gax-httpjson/pom.xml
+++ /dev/null
@@ -1,114 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <artifactId>gax-httpjson</artifactId>
-  <version>0.105.1</version> <!-- {x-version-update:gax-httpjson:current} -->
-  <packaging>jar</packaging>
-  <name>GAX (Google Api eXtensions) for Java (HTTP JSON)</name>
-  <description>Google Api eXtensions for Java (HTTP JSON)</description>
-
-  <parent>
-    <groupId>com.google.api</groupId>
-    <artifactId>gax-parent</artifactId>
-    <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-  </parent>
-
-  <properties>
-    <!-- Skip breaking changes checking against previous version while gax-httpjson is not GA -->
-    <clirr.skip>true</clirr.skip>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>gax</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>api-common</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api.grpc</groupId>
-      <artifactId>proto-google-common-protos</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-credentials</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.code.gson</groupId>
-      <artifactId>gson</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.guava</groupId>
-      <artifactId>guava</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.http-client</groupId>
-      <artifactId>google-http-client</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.protobuf</groupId>
-      <artifactId>protobuf-java</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>org.threeten</groupId>
-      <artifactId>threetenbp</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-oauth2-http</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.http-client</groupId>
-      <artifactId>google-http-client-gson</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.protobuf</groupId>
-      <artifactId>protobuf-java-util</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.code.findbugs</groupId>
-      <artifactId>jsr305</artifactId>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auto.value</groupId>
-      <artifactId>auto-value-annotations</artifactId>
-      <scope>provided</scope>
-    </dependency>
-
-    <!-- test dependencies -->
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>gax</artifactId>
-      <type>test-jar</type>
-      <scope>test</scope>
-      <classifier>testlib</classifier>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <executions>
-          <execution>
-            <goals>
-              <goal>test-jar</goal>
-            </goals>
-            <configuration>
-              <skip>false</skip>
-              <classifier>testlib</classifier>
-              <includes>
-                <include>com/google/api/gax/httpjson/testing/**</include>
-              </includes>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
-</project>
\ No newline at end of file
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java
deleted file mode 100644
index 6952f4885..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.auto.value.AutoValue;
-import javax.annotation.Nullable;
-
-@BetaApi
-@AutoValue
-/* Method descriptor for messages to be transmitted over HTTP. */
-public abstract class ApiMethodDescriptor<RequestT, ResponseT> {
-  public enum MethodType {
-    UNARY,
-    CLIENT_STREAMING,
-    SERVER_STREAMING,
-    BIDI_STREAMING,
-    UNKNOWN;
-  }
-
-  public abstract String getFullMethodName();
-
-  public abstract HttpRequestFormatter<RequestT> getRequestFormatter();
-
-  public abstract HttpResponseParser<ResponseT> getResponseParser();
-
-  /** Return the HTTP method for this request message type. */
-  @Nullable
-  public abstract String getHttpMethod();
-
-  @Nullable
-  public abstract OperationSnapshotFactory<RequestT, ResponseT> getOperationSnapshotFactory();
-
-  @Nullable
-  public abstract PollingRequestFactory<RequestT> getPollingRequestFactory();
-
-  public abstract MethodType getType();
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new AutoValue_ApiMethodDescriptor.Builder<RequestT, ResponseT>()
-        .setType(MethodType.UNARY);
-  }
-
-  public abstract Builder<RequestT, ResponseT> toBuilder();
-
-  @AutoValue.Builder
-  public abstract static class Builder<RequestT, ResponseT> {
-
-    public abstract Builder<RequestT, ResponseT> setFullMethodName(String fullMethodName);
-
-    public abstract Builder<RequestT, ResponseT> setRequestFormatter(
-        HttpRequestFormatter<RequestT> requestFormatter);
-
-    public abstract HttpRequestFormatter<RequestT> getRequestFormatter();
-
-    public abstract Builder<RequestT, ResponseT> setResponseParser(
-        HttpResponseParser<ResponseT> responseParser);
-
-    public abstract Builder<RequestT, ResponseT> setHttpMethod(String httpMethod);
-
-    public abstract Builder<RequestT, ResponseT> setOperationSnapshotFactory(
-        OperationSnapshotFactory<RequestT, ResponseT> operationSnapshotFactory);
-
-    public abstract Builder<RequestT, ResponseT> setPollingRequestFactory(
-        PollingRequestFactory<RequestT> pollingRequestFactory);
-
-    public abstract Builder<RequestT, ResponseT> setType(MethodType type);
-
-    public abstract ApiMethodDescriptor<RequestT, ResponseT> build();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java
deleted file mode 100644
index 024e8d3d1..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-/**
- * A functional interface to be implemented for each request message to extract specific fields from
- * it. For advanced usage only.
- */
-public interface FieldsExtractor<RequestT, ParamsT> {
-  ParamsT extract(RequestT request);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCall.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCall.java
deleted file mode 100644
index 8539b2b50..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCall.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import javax.annotation.Nullable;
-
-/**
- * A {@link HttpJsonClientCall} which forwards all of its methods to another {@link
- * HttpJsonClientCall}.
- */
-@BetaApi
-public abstract class ForwardingHttpJsonClientCall<RequestT, ResponseT>
-    extends HttpJsonClientCall<RequestT, ResponseT> {
-
-  protected abstract HttpJsonClientCall<RequestT, ResponseT> delegate();
-
-  @Override
-  public void start(Listener<ResponseT> responseListener, HttpJsonMetadata requestHeaders) {
-    delegate().start(responseListener, requestHeaders);
-  }
-
-  @Override
-  public void request(int numMessages) {
-    delegate().request(numMessages);
-  }
-
-  @Override
-  public void cancel(@Nullable String message, @Nullable Throwable cause) {
-    delegate().cancel(message, cause);
-  }
-
-  @Override
-  public void halfClose() {
-    delegate().halfClose();
-  }
-
-  @Override
-  public void sendMessage(RequestT message) {
-    delegate().sendMessage(message);
-  }
-
-  /**
-   * A simplified version of {@link ForwardingHttpJsonClientCall} where subclasses can pass in a
-   * {@link HttpJsonClientCall} as the delegate.
-   */
-  public abstract static class SimpleForwardingHttpJsonClientCall<RequestT, ResponseT>
-      extends ForwardingHttpJsonClientCall<RequestT, ResponseT> {
-
-    private final HttpJsonClientCall<RequestT, ResponseT> delegate;
-
-    protected SimpleForwardingHttpJsonClientCall(HttpJsonClientCall<RequestT, ResponseT> delegate) {
-      this.delegate = delegate;
-    }
-
-    @Override
-    protected HttpJsonClientCall<RequestT, ResponseT> delegate() {
-      return delegate;
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCallListener.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCallListener.java
deleted file mode 100644
index 8c64b957f..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ForwardingHttpJsonClientCallListener.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-
-/**
- * A {@link HttpJsonClientCall.Listener} which forwards all of its methods to another {@link
- * HttpJsonClientCall.Listener}.
- */
-@BetaApi
-public abstract class ForwardingHttpJsonClientCallListener<ResponseT>
-    extends HttpJsonClientCall.Listener<ResponseT> {
-
-  protected abstract HttpJsonClientCall.Listener<ResponseT> delegate();
-
-  @Override
-  public void onHeaders(HttpJsonMetadata responseHeaders) {
-    delegate().onHeaders(responseHeaders);
-  }
-
-  @Override
-  public void onMessage(ResponseT message) {
-    delegate().onMessage(message);
-  }
-
-  @Override
-  public void onClose(int statusCode, HttpJsonMetadata trailers) {
-    delegate().onClose(statusCode, trailers);
-  }
-
-  /**
-   * A simplified version of {@link ForwardingHttpJsonClientCallListener} where subclasses can pass
-   * in a {@link HttpJsonClientCall.Listener} as the delegate.
-   */
-  public abstract static class SimpleForwardingHttpJsonClientCallListener<ResponseT>
-      extends ForwardingHttpJsonClientCallListener<ResponseT> {
-
-    private final HttpJsonClientCall.Listener<ResponseT> delegate;
-
-    protected SimpleForwardingHttpJsonClientCallListener(
-        HttpJsonClientCall.Listener<ResponseT> delegate) {
-      this.delegate = delegate;
-    }
-
-    @Override
-    protected HttpJsonClientCall.Listener<ResponseT> delegate() {
-      return delegate;
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/GaxHttpJsonProperties.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/GaxHttpJsonProperties.java
deleted file mode 100644
index fab63c320..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/GaxHttpJsonProperties.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.InternalApi;
-import java.util.regex.Pattern;
-
-/** Provides properties of the GAX-HTTPJSON library. */
-@InternalApi
-public class GaxHttpJsonProperties {
-  private static final Pattern DEFAULT_API_CLIENT_HEADER_PATTERN =
-      Pattern.compile("gl-java/.+ gapic/.* gax/.+ rest/.*");
-
-  /** Returns default api client header pattern (to facilitate testing) */
-  public static Pattern getDefaultApiClientHeaderPattern() {
-    return DEFAULT_API_CLIENT_HEADER_PATTERN;
-  }
-
-  public static String getHttpJsonTokenName() {
-    return "rest";
-  }
-
-  public static String getHttpJsonVersion() {
-    return "";
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpHeadersUtils.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpHeadersUtils.java
deleted file mode 100644
index 8f1ce432e..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpHeadersUtils.java
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpHeaders;
-import com.google.api.client.util.ClassInfo;
-import com.google.api.client.util.FieldInfo;
-import com.google.api.core.InternalApi;
-import com.google.common.collect.ImmutableList;
-import java.util.List;
-import java.util.Map;
-
-/** This class is for internal use only and is public for technical reasons. */
-@InternalApi
-public class HttpHeadersUtils {
-  public static String getUserAgentValue(Map<String, String> headersMap) {
-    for (Map.Entry<String, String> entry : headersMap.entrySet()) {
-      if ("user-agent".equalsIgnoreCase(entry.getKey())) {
-        return entry.getValue();
-      }
-    }
-    return null;
-  }
-
-  public static HttpHeaders setHeaders(HttpHeaders headers, Map<String, String> headersMap) {
-    for (Map.Entry<String, String> entry : headersMap.entrySet()) {
-      setHeader(headers, entry.getKey(), entry.getValue());
-    }
-    return headers;
-  }
-
-  public static HttpHeaders setHeader(HttpHeaders headers, String key, String value) {
-    ClassInfo classInfo = headers.getClassInfo();
-    FieldInfo fieldInfo = classInfo.getFieldInfo(key);
-    Object headerValue;
-    if (fieldInfo == null) {
-      headerValue = value;
-    } else {
-      Class<?> elementyType = fieldInfo.getType();
-      if (List.class.isAssignableFrom(fieldInfo.getType())) {
-        elementyType =
-            "Age".equalsIgnoreCase(key) || "Content-Length".equalsIgnoreCase(key)
-                ? Long.class
-                : String.class;
-      }
-      headerValue = ImmutableList.of(fromString(elementyType, value));
-    }
-    headers.set(key, headerValue);
-    return headers;
-  }
-
-  private static Object fromString(Class<?> clazz, String stringValue) {
-    if (String.class == clazz) {
-      return stringValue;
-    } else if (Long.class == clazz) {
-      return Long.valueOf(stringValue);
-    }
-
-    // It seems only String and Long have chances of being used. Not adding other
-    // classes to avoid having dead code, even though without them this looks incomplete.
-    throw new IllegalArgumentException(
-        "Instantiating "
-            + clazz
-            + " from string representation is not supported. Most likely an"
-            + " incompatible version of google-http-client was used.");
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonApiExceptionFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonApiExceptionFactory.java
deleted file mode 100644
index a48f0b5a2..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonApiExceptionFactory.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpResponseException;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.collect.ImmutableSet;
-import java.util.Set;
-import java.util.concurrent.CancellationException;
-
-class HttpJsonApiExceptionFactory {
-  private final Set<Code> retryableCodes;
-
-  HttpJsonApiExceptionFactory(Set<Code> retryableCodes) {
-    this.retryableCodes = ImmutableSet.copyOf(retryableCodes);
-  }
-
-  ApiException create(Throwable throwable) {
-    if (throwable instanceof HttpResponseException) {
-      HttpResponseException e = (HttpResponseException) throwable;
-      StatusCode statusCode = HttpJsonStatusCode.of(e.getStatusCode());
-      boolean canRetry = retryableCodes.contains(statusCode.getCode());
-      String message = e.getStatusMessage();
-      return createApiException(throwable, statusCode, message, canRetry);
-    } else if (throwable instanceof HttpJsonStatusRuntimeException) {
-      HttpJsonStatusRuntimeException e = (HttpJsonStatusRuntimeException) throwable;
-      StatusCode statusCode = HttpJsonStatusCode.of(e.getStatusCode());
-      return createApiException(
-          throwable, statusCode, e.getMessage(), retryableCodes.contains(statusCode.getCode()));
-    } else if (throwable instanceof CancellationException) {
-      return ApiExceptionFactory.createException(
-          throwable, HttpJsonStatusCode.of(Code.CANCELLED), false);
-    } else if (throwable instanceof ApiException) {
-      return (ApiException) throwable;
-    } else {
-      // Do not retry on unknown throwable, even when UNKNOWN is in retryableCodes
-      return ApiExceptionFactory.createException(
-          throwable, HttpJsonStatusCode.of(StatusCode.Code.UNKNOWN), false);
-    }
-  }
-
-  private ApiException createApiException(
-      Throwable throwable, StatusCode statusCode, String message, boolean canRetry) {
-    return message == null
-        ? ApiExceptionFactory.createException(throwable, statusCode, canRetry)
-        : ApiExceptionFactory.createException(message, throwable, statusCode, canRetry);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallContext.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallContext.java
deleted file mode 100644
index 469435d60..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallContext.java
+++ /dev/null
@@ -1,530 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.internal.ApiCallContextOptions;
-import com.google.api.gax.rpc.internal.Headers;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.api.gax.tracing.BaseApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-import org.threeten.bp.Instant;
-
-/**
- * HttpJsonCallContext encapsulates context data used to make an http-json call.
- *
- * <p>HttpJsonCallContext is immutable in the sense that none of its methods modifies the
- * HttpJsonCallContext itself or the underlying data. Methods of the form {@code withX} return
- * copies of the object, but with one field changed. The immutability and thread safety of the
- * arguments solely depends on the arguments themselves.
- */
-@BetaApi("Reference ApiCallContext instead - this class is likely to experience breaking changes")
-public final class HttpJsonCallContext implements ApiCallContext {
-  private final HttpJsonChannel channel;
-  private final HttpJsonCallOptions callOptions;
-  @Nullable private final Duration timeout;
-  @Nullable private final Duration streamWaitTimeout;
-  @Nullable private final Duration streamIdleTimeout;
-  private final ImmutableMap<String, List<String>> extraHeaders;
-  private final ApiCallContextOptions options;
-  private final ApiTracer tracer;
-  @Nullable private final RetrySettings retrySettings;
-  @Nullable private final ImmutableSet<StatusCode.Code> retryableCodes;
-
-  /** Returns an empty instance. */
-  public static HttpJsonCallContext createDefault() {
-    return new HttpJsonCallContext(
-        null,
-        HttpJsonCallOptions.newBuilder().build(),
-        null,
-        null,
-        null,
-        ImmutableMap.of(),
-        ApiCallContextOptions.getDefaultOptions(),
-        null,
-        null,
-        null);
-  }
-
-  public static HttpJsonCallContext of(HttpJsonChannel channel, HttpJsonCallOptions options) {
-    return new HttpJsonCallContext(
-        channel,
-        options,
-        null,
-        null,
-        null,
-        ImmutableMap.of(),
-        ApiCallContextOptions.getDefaultOptions(),
-        null,
-        null,
-        null);
-  }
-
-  private HttpJsonCallContext(
-      HttpJsonChannel channel,
-      HttpJsonCallOptions callOptions,
-      Duration timeout,
-      Duration streamWaitTimeout,
-      Duration streamIdleTimeout,
-      ImmutableMap<String, List<String>> extraHeaders,
-      ApiCallContextOptions options,
-      ApiTracer tracer,
-      RetrySettings defaultRetrySettings,
-      Set<StatusCode.Code> defaultRetryableCodes) {
-    this.channel = channel;
-    this.callOptions = callOptions;
-    this.timeout = timeout;
-    this.streamWaitTimeout = streamWaitTimeout;
-    this.streamIdleTimeout = streamIdleTimeout;
-    this.extraHeaders = extraHeaders;
-    this.options = options;
-    this.tracer = tracer;
-    this.retrySettings = defaultRetrySettings;
-    this.retryableCodes =
-        defaultRetryableCodes == null ? null : ImmutableSet.copyOf(defaultRetryableCodes);
-  }
-
-  /**
-   * Returns inputContext cast to {@link HttpJsonCallContext}, or an empty {@link
-   * HttpJsonCallContext} if inputContext is null.
-   *
-   * @param inputContext the {@link ApiCallContext} to cast if it is not null
-   */
-  @Override
-  public HttpJsonCallContext nullToSelf(ApiCallContext inputContext) {
-    HttpJsonCallContext httpJsonCallContext;
-    if (inputContext == null) {
-      httpJsonCallContext = this;
-    } else {
-      if (!(inputContext instanceof HttpJsonCallContext)) {
-        throw new IllegalArgumentException(
-            "context must be an instance of HttpJsonCallContext, but found "
-                + inputContext.getClass().getName());
-      }
-      httpJsonCallContext = (HttpJsonCallContext) inputContext;
-    }
-    return httpJsonCallContext;
-  }
-
-  @Override
-  public HttpJsonCallContext merge(ApiCallContext inputCallContext) {
-    if (inputCallContext == null) {
-      return this;
-    }
-    if (!(inputCallContext instanceof HttpJsonCallContext)) {
-      throw new IllegalArgumentException(
-          "context must be an instance of HttpJsonCallContext, but found "
-              + inputCallContext.getClass().getName());
-    }
-    HttpJsonCallContext httpJsonCallContext = (HttpJsonCallContext) inputCallContext;
-
-    HttpJsonChannel newChannel = httpJsonCallContext.channel;
-    if (newChannel == null) {
-      newChannel = this.channel;
-    }
-
-    // Do deep merge of callOptions
-    HttpJsonCallOptions newCallOptions = callOptions.merge(httpJsonCallContext.callOptions);
-
-    Duration newTimeout = httpJsonCallContext.timeout;
-    if (newTimeout == null) {
-      newTimeout = this.timeout;
-    }
-
-    Duration newStreamWaitTimeout = httpJsonCallContext.streamWaitTimeout;
-    if (newStreamWaitTimeout == null) {
-      newStreamWaitTimeout = streamWaitTimeout;
-    }
-
-    Duration newStreamIdleTimeout = httpJsonCallContext.streamIdleTimeout;
-    if (newStreamIdleTimeout == null) {
-      newStreamIdleTimeout = streamIdleTimeout;
-    }
-
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(extraHeaders, httpJsonCallContext.extraHeaders);
-
-    ApiCallContextOptions newOptions = options.merge(httpJsonCallContext.options);
-
-    ApiTracer newTracer = httpJsonCallContext.tracer;
-    if (newTracer == null) {
-      newTracer = this.tracer;
-    }
-
-    RetrySettings newRetrySettings = httpJsonCallContext.retrySettings;
-    if (newRetrySettings == null) {
-      newRetrySettings = this.retrySettings;
-    }
-
-    Set<StatusCode.Code> newRetryableCodes = httpJsonCallContext.retryableCodes;
-    if (newRetryableCodes == null) {
-      newRetryableCodes = this.retryableCodes;
-    }
-
-    return new HttpJsonCallContext(
-        newChannel,
-        newCallOptions,
-        newTimeout,
-        newStreamWaitTimeout,
-        newStreamIdleTimeout,
-        newExtraHeaders,
-        newOptions,
-        newTracer,
-        newRetrySettings,
-        newRetryableCodes);
-  }
-
-  @Override
-  public HttpJsonCallContext withCredentials(Credentials newCredentials) {
-    HttpJsonCallOptions.Builder builder =
-        callOptions != null ? callOptions.toBuilder() : HttpJsonCallOptions.newBuilder();
-    return withCallOptions(builder.setCredentials(newCredentials).build());
-  }
-
-  @Override
-  public HttpJsonCallContext withTransportChannel(TransportChannel inputChannel) {
-    Preconditions.checkNotNull(inputChannel);
-    if (!(inputChannel instanceof HttpJsonTransportChannel)) {
-      throw new IllegalArgumentException(
-          "Expected HttpJsonTransportChannel, got " + inputChannel.getClass().getName());
-    }
-    HttpJsonTransportChannel transportChannel = (HttpJsonTransportChannel) inputChannel;
-    return withChannel(transportChannel.getChannel());
-  }
-
-  @Override
-  public HttpJsonCallContext withTimeout(Duration timeout) {
-    // Default RetrySettings use 0 for RPC timeout. Treat that as disabled timeouts.
-    if (timeout != null && (timeout.isZero() || timeout.isNegative())) {
-      timeout = null;
-    }
-
-    // Prevent expanding deadlines
-    if (timeout != null && this.timeout != null && this.timeout.compareTo(timeout) <= 0) {
-      return this;
-    }
-
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Nullable
-  @Override
-  public Duration getTimeout() {
-    return timeout;
-  }
-
-  @Override
-  public HttpJsonCallContext withStreamWaitTimeout(@Nullable Duration streamWaitTimeout) {
-    if (streamWaitTimeout != null) {
-      Preconditions.checkArgument(
-          streamWaitTimeout.compareTo(Duration.ZERO) >= 0, "Invalid timeout: < 0 s");
-    }
-
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  /**
-   * The stream wait timeout set for this context.
-   *
-   * @see ApiCallContext#withStreamWaitTimeout(Duration)
-   */
-  @Override
-  @Nullable
-  public Duration getStreamWaitTimeout() {
-    return streamWaitTimeout;
-  }
-
-  @Override
-  public HttpJsonCallContext withStreamIdleTimeout(@Nullable Duration streamIdleTimeout) {
-    if (streamIdleTimeout != null) {
-      Preconditions.checkArgument(
-          streamIdleTimeout.compareTo(Duration.ZERO) >= 0, "Invalid timeout: < 0 s");
-    }
-
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  /**
-   * The stream idle timeout set for this context.
-   *
-   * @see ApiCallContext#withStreamIdleTimeout(Duration)
-   */
-  @Override
-  @Nullable
-  public Duration getStreamIdleTimeout() {
-    return streamIdleTimeout;
-  }
-
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  @Override
-  public ApiCallContext withExtraHeaders(Map<String, List<String>> extraHeaders) {
-    Preconditions.checkNotNull(extraHeaders);
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(this.extraHeaders, extraHeaders);
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        newExtraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  @Override
-  public Map<String, List<String>> getExtraHeaders() {
-    return extraHeaders;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public <T> ApiCallContext withOption(Key<T> key, T value) {
-    ApiCallContextOptions newOptions = options.withOption(key, value);
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        newOptions,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public <T> T getOption(Key<T> key) {
-    return options.getOption(key);
-  }
-
-  public HttpJsonChannel getChannel() {
-    return channel;
-  }
-
-  public HttpJsonCallOptions getCallOptions() {
-    return callOptions;
-  }
-
-  @Deprecated
-  @Nullable
-  public Instant getDeadline() {
-    return getCallOptions() != null ? getCallOptions().getDeadline() : null;
-  }
-
-  @Deprecated
-  @Nullable
-  public Credentials getCredentials() {
-    return getCallOptions() != null ? getCallOptions().getCredentials() : null;
-  }
-
-  @Override
-  public RetrySettings getRetrySettings() {
-    return retrySettings;
-  }
-
-  @Override
-  public HttpJsonCallContext withRetrySettings(RetrySettings retrySettings) {
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public Set<StatusCode.Code> getRetryableCodes() {
-    return retryableCodes;
-  }
-
-  @Override
-  public HttpJsonCallContext withRetryableCodes(Set<StatusCode.Code> retryableCodes) {
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        retryableCodes);
-  }
-
-  public HttpJsonCallContext withChannel(HttpJsonChannel newChannel) {
-    return new HttpJsonCallContext(
-        newChannel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  public HttpJsonCallContext withCallOptions(HttpJsonCallOptions newCallOptions) {
-    return new HttpJsonCallContext(
-        this.channel,
-        newCallOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Deprecated
-  public HttpJsonCallContext withDeadline(Instant newDeadline) {
-    HttpJsonCallOptions.Builder builder =
-        callOptions != null ? callOptions.toBuilder() : HttpJsonCallOptions.newBuilder();
-    return withCallOptions(builder.setDeadline(newDeadline).build());
-  }
-
-  @Nonnull
-  @Override
-  public ApiTracer getTracer() {
-    if (tracer == null) {
-      return BaseApiTracer.getInstance();
-    }
-    return tracer;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public HttpJsonCallContext withTracer(@Nonnull ApiTracer newTracer) {
-    Preconditions.checkNotNull(newTracer);
-
-    return new HttpJsonCallContext(
-        this.channel,
-        this.callOptions,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        newTracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-    HttpJsonCallContext that = (HttpJsonCallContext) o;
-    return Objects.equals(this.channel, that.channel)
-        && Objects.equals(this.callOptions, that.callOptions)
-        && Objects.equals(this.timeout, that.timeout)
-        && Objects.equals(this.extraHeaders, that.extraHeaders)
-        && Objects.equals(this.options, that.options)
-        && Objects.equals(this.tracer, that.tracer)
-        && Objects.equals(this.retrySettings, that.retrySettings)
-        && Objects.equals(this.retryableCodes, that.retryableCodes);
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(
-        channel,
-        callOptions,
-        timeout,
-        extraHeaders,
-        options,
-        tracer,
-        retrySettings,
-        retryableCodes);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallOptions.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallOptions.java
deleted file mode 100644
index dbb3cb625..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallOptions.java
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.auth.Credentials;
-import com.google.auto.value.AutoValue;
-import com.google.protobuf.TypeRegistry;
-import javax.annotation.Nullable;
-import org.threeten.bp.Instant;
-
-/** Options for an http-json call, including deadline and credentials. */
-@BetaApi
-@AutoValue
-public abstract class HttpJsonCallOptions {
-  public static final HttpJsonCallOptions DEFAULT = newBuilder().build();
-
-  @Nullable
-  public abstract Instant getDeadline();
-
-  @Nullable
-  public abstract Credentials getCredentials();
-
-  @Nullable
-  public abstract TypeRegistry getTypeRegistry();
-
-  public abstract Builder toBuilder();
-
-  public static Builder newBuilder() {
-    return new AutoValue_HttpJsonCallOptions.Builder();
-  }
-
-  public HttpJsonCallOptions merge(HttpJsonCallOptions inputOptions) {
-    if (inputOptions == null) {
-      return this;
-    }
-
-    Builder builder = this.toBuilder();
-
-    Instant newDeadline = inputOptions.getDeadline();
-    if (newDeadline != null) {
-      builder.setDeadline(newDeadline);
-    }
-
-    Credentials newCredentials = inputOptions.getCredentials();
-    if (newCredentials != null) {
-      builder.setCredentials(newCredentials);
-    }
-
-    TypeRegistry newTypeRegistry = inputOptions.getTypeRegistry();
-    if (newTypeRegistry != null) {
-      builder.setTypeRegistry(newTypeRegistry);
-    }
-
-    return builder.build();
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setDeadline(Instant value);
-
-    public abstract Builder setCredentials(Credentials value);
-
-    public abstract Builder setTypeRegistry(TypeRegistry value);
-
-    public abstract HttpJsonCallOptions build();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallSettings.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallSettings.java
deleted file mode 100644
index ac013ed74..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallSettings.java
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.protobuf.TypeRegistry;
-
-/** HTTP-specific settings for creating callables. */
-public class HttpJsonCallSettings<RequestT, ResponseT> {
-  private final ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor;
-  private final TypeRegistry typeRegistry;
-
-  private HttpJsonCallSettings(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, TypeRegistry typeRegistry) {
-    this.methodDescriptor = methodDescriptor;
-    this.typeRegistry = typeRegistry;
-  }
-
-  public ApiMethodDescriptor<RequestT, ResponseT> getMethodDescriptor() {
-    return methodDescriptor;
-  }
-
-  public TypeRegistry getTypeRegistry() {
-    return typeRegistry;
-  }
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new Builder<>();
-  }
-
-  public static <RequestT, ResponseT> HttpJsonCallSettings<RequestT, ResponseT> create(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor) {
-    return HttpJsonCallSettings.<RequestT, ResponseT>newBuilder()
-        .setMethodDescriptor(methodDescriptor)
-        .build();
-  }
-
-  public Builder toBuilder() {
-    return new Builder<>(this);
-  }
-
-  public static class Builder<RequestT, ResponseT> {
-    private ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor;
-    private TypeRegistry typeRegistry;
-
-    private Builder() {}
-
-    private Builder(HttpJsonCallSettings<RequestT, ResponseT> settings) {
-      this.methodDescriptor = settings.methodDescriptor;
-    }
-
-    public Builder<RequestT, ResponseT> setMethodDescriptor(
-        ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor) {
-      this.methodDescriptor = methodDescriptor;
-      return this;
-    }
-
-    public Builder<RequestT, ResponseT> setTypeRegistry(TypeRegistry typeRegistry) {
-      this.typeRegistry = typeRegistry;
-      return this;
-    }
-
-    public HttpJsonCallSettings<RequestT, ResponseT> build() {
-      return new HttpJsonCallSettings<>(methodDescriptor, typeRegistry);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallableFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallableFactory.java
deleted file mode 100644
index 6131c911f..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonCallableFactory.java
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.Callables;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.tracing.SpanName;
-import com.google.api.gax.tracing.TracedUnaryCallable;
-import com.google.common.base.Preconditions;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-import javax.annotation.Nonnull;
-
-/** Class with utility methods to create http/json-based direct callables. */
-public class HttpJsonCallableFactory {
-  // Used to extract service and method name from a grpc MethodDescriptor.
-  // fullMethodName has the format: service.resource.action
-  // For example: compute.instances.addAccessConfig
-  private static final Pattern FULL_METHOD_NAME_REGEX = Pattern.compile("^(.+)\\.(.+)$");
-
-  private HttpJsonCallableFactory() {}
-
-  private static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createDirectUnaryCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings) {
-    return new HttpJsonDirectCallable<RequestT, ResponseT>(
-        httpJsonCallSettings.getMethodDescriptor(), httpJsonCallSettings.getTypeRegistry());
-  }
-
-  static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      UnaryCallSettings<?, ?> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        new HttpJsonExceptionCallable<>(innerCallable, callSettings.getRetryableCodes());
-    callable = Callables.retrying(callable, callSettings, clientContext);
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a Unary callable object with minimal http/json-specific functionality. Designed for use
-   * by generated code.
-   *
-   * @param httpJsonCallSettings the gRPC call settings
-   * @param callSettings the unary call settings
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBaseUnaryCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      UnaryCallSettings<?, ?> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
-    callable = new HttpJsonExceptionCallable<>(callable, callSettings.getRetryableCodes());
-    callable = Callables.retrying(callable, callSettings, clientContext);
-
-    return callable;
-  }
-
-  /**
-   * Create a callable object with http/json-specific functionality. Designed for use by generated
-   * code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param callSettings {@link UnaryCallSettings} to configure the method-level settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> innerCallable =
-        createDirectUnaryCallable(httpJsonCallSettings);
-
-    innerCallable =
-        new TracedUnaryCallable<>(
-            innerCallable,
-            clientContext.getTracerFactory(),
-            getSpanName(httpJsonCallSettings.getMethodDescriptor()));
-
-    return createUnaryCallable(innerCallable, callSettings, clientContext);
-  }
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
-    callable = createUnaryCallable(callable, pagedCallSettings, clientContext);
-    UnaryCallable<RequestT, PagedListResponseT> pagedCallable =
-        Callables.paged(callable, pagedCallSettings);
-    return pagedCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable = createDirectUnaryCallable(httpJsonCallSettings);
-    callable = createUnaryCallable(callable, batchingCallSettings, clientContext);
-    callable = Callables.batching(callable, batchingCallSettings, clientContext);
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  public static <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          LongRunningClient longRunningClient,
-          UnaryCallable<RequestT, OperationSnapshot> operationSnapshotCallable) {
-    OperationCallable<RequestT, ResponseT, MetadataT> operationCallable =
-        Callables.longRunningOperation(
-            operationSnapshotCallable, operationCallSettings, clientContext, longRunningClient);
-    return operationCallable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  public static <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          HttpJsonCallSettings<RequestT, ResponseT> httpJsoncallSettings,
-          ServerStreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-
-    ServerStreamingCallable<RequestT, ResponseT> callable =
-        new HttpJsonDirectServerStreamingCallable<>(httpJsoncallSettings.getMethodDescriptor());
-
-    callable =
-        new HttpJsonExceptionServerStreamingCallable<>(
-            callable, streamingCallSettings.getRetryableCodes());
-
-    if (clientContext.getStreamWatchdog() != null) {
-      callable = Callables.watched(callable, streamingCallSettings, clientContext);
-    }
-
-    callable = Callables.retrying(callable, streamingCallSettings, clientContext);
-    return callable.withDefaultCallContext(clientContext.getDefaultCallContext());
-  }
-
-  @InternalApi("Visible for testing")
-  static SpanName getSpanName(@Nonnull ApiMethodDescriptor<?, ?> methodDescriptor) {
-    Matcher matcher = FULL_METHOD_NAME_REGEX.matcher(methodDescriptor.getFullMethodName());
-
-    Preconditions.checkArgument(matcher.matches(), "Invalid fullMethodName");
-    return SpanName.of(matcher.group(1), matcher.group(2));
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonChannel.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonChannel.java
deleted file mode 100644
index 96db96b46..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonChannel.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-
-/** HttpJsonChannel contains the functionality to issue http-json calls. */
-@BetaApi
-public interface HttpJsonChannel {
-  <RequestT, ResponseT> HttpJsonClientCall<RequestT, ResponseT> newCall(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, HttpJsonCallOptions callOptions);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCall.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCall.java
deleted file mode 100644
index 16ecd6795..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCall.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import javax.annotation.Nullable;
-
-// This class mimics the structure and behavior of the corresponding ClientCall from gRPC package as
-// closely as possible.
-/**
- * An instance of a call to a remote method. A call will send zero or more request messages to the
- * server and receive zero or more response messages back.
- *
- * <p>Instances are created by a {@link HttpJsonChannel} and used by stubs to invoke their remote
- * behavior.
- *
- * <p>{@link #start} must be called prior to calling any other methods, with the exception of {@link
- * #cancel}. Whereas {@link #cancel} must not be followed by any other methods, but can be called
- * more than once, while only the first one has effect.
- *
- * <p>Methods are potentially blocking but are designed to execute quickly. The implementations of
- * this class are expected to be thread-safe.
- *
- * <p>There is a race between {@link #cancel} and the completion/failure of the RPC in other ways.
- * If {@link #cancel} won the race, {@link HttpJsonClientCall.Listener#onClose Listener.onClose()}
- * is called with {@code statusCode} corresponding to {@link
- * com.google.api.gax.rpc.StatusCode.Code#CANCELLED CANCELLED}. Otherwise, {@link
- * HttpJsonClientCall.Listener#onClose Listener.onClose()} is called with whatever status the RPC
- * was finished. We ensure that at most one is called.
- *
- * @param <RequestT> type of message sent to the server
- * @param <ResponseT> type of message received one or more times from the server
- */
-@BetaApi
-public abstract class HttpJsonClientCall<RequestT, ResponseT> {
-  /**
-   * Callbacks for receiving metadata, response messages and completion status from the server.
-   *
-   * <p>Implementations are discouraged to block for extended periods of time. Implementations are
-   * not required to be thread-safe, but they must not be thread-hostile. The caller is free to call
-   * an instance from multiple threads, but only one call simultaneously.
-   */
-  @BetaApi
-  public abstract static class Listener<T> {
-    /**
-     * The response headers have been received. Headers always precede messages.
-     *
-     * @param responseHeaders containing metadata sent by the server at the start of the response
-     */
-    public void onHeaders(HttpJsonMetadata responseHeaders) {}
-
-    /**
-     * A response message has been received. May be called zero or more times depending on whether
-     * the call response is empty, a single message or a stream of messages.
-     *
-     * @param message returned by the server
-     */
-    public void onMessage(T message) {}
-
-    /**
-     * The ClientCall has been closed. Any additional calls to the {@code ClientCall} will not be
-     * processed by the server. No further receiving will occur and no further notifications will be
-     * made.
-     *
-     * <p>This method should not throw. If this method throws, there is no way to be notified of the
-     * exception. Implementations should therefore be careful of exceptions which can accidentally
-     * leak resources.
-     *
-     * @param statusCode the HTTP status code representing the result of the remote call
-     * @param trailers metadata provided at call completion
-     */
-    public void onClose(int statusCode, HttpJsonMetadata trailers) {}
-  }
-
-  /**
-   * Start a call, using {@code responseListener} for processing response messages.
-   *
-   * <p>It must be called prior to any other method on this class, except for {@link #cancel} which
-   * may be called at any time.
-   *
-   * @param responseListener receives response messages
-   * @param requestHeaders which can contain extra call metadata, e.g. authentication credentials.
-   */
-  public abstract void start(Listener<ResponseT> responseListener, HttpJsonMetadata requestHeaders);
-
-  /**
-   * Requests up to the given number of messages from the call to be delivered to {@link
-   * HttpJsonClientCall.Listener#onMessage(Object)}. No additional messages will be delivered.
-   *
-   * <p>Message delivery is guaranteed to be sequential in the order received. In addition, the
-   * listener methods will not be accessed concurrently. While it is not guaranteed that the same
-   * thread will always be used, it is guaranteed that only a single thread will access the listener
-   * at a time.
-   *
-   * <p>If called multiple times, the number of messages able to delivered will be the sum of the
-   * calls.
-   *
-   * <p>This method is safe to call from multiple threads without external synchronization.
-   *
-   * @param numMessages the requested number of messages to be delivered to the listener. Must be
-   *     non-negative.
-   */
-  public abstract void request(int numMessages);
-
-  /**
-   * Prevent any further processing for this {@code HttpJsonClientCall}. No further messages may be
-   * sent or will be received. The server is not informed of cancellations. Cancellation is
-   * permitted even if previously {@link #halfClose}d. Cancelling an already {@code cancel()}ed
-   * {@code ClientCall} has no effect.
-   *
-   * <p>No other methods on this class can be called after this method has been called.
-   *
-   * @param message if not {@code null}, will appear as the description of the CANCELLED status
-   * @param cause if not {@code null}, will appear as the cause of the CANCELLED status
-   */
-  public abstract void cancel(@Nullable String message, @Nullable Throwable cause);
-
-  /**
-   * Close the call for request message sending. Incoming response messages are unaffected. This
-   * should be called when no more messages will be sent from the client.
-   */
-  public abstract void halfClose();
-
-  /**
-   * Send a request message to the server. May be called zero or more times but for unary and server
-   * streaming calls it must be called not more than once.
-   *
-   * @param message message to be sent to the server.
-   */
-  public abstract void sendMessage(RequestT message);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCallImpl.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCallImpl.java
deleted file mode 100644
index 9f52712b2..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCallImpl.java
+++ /dev/null
@@ -1,493 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpTransport;
-import com.google.api.gax.httpjson.ApiMethodDescriptor.MethodType;
-import com.google.api.gax.httpjson.HttpRequestRunnable.ResultListener;
-import com.google.api.gax.httpjson.HttpRequestRunnable.RunnableResult;
-import com.google.common.base.Preconditions;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.Reader;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayDeque;
-import java.util.Queue;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.Executor;
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-
-/**
- * This class serves as main implementation of {@link HttpJsonClientCall} for REST transport and is
- * expected to be used for every REST call. It currently supports unary and server-streaming
- * workflows. The overall behavior and surface of the class mimics as close as possible behavior of
- * the corresponding ClientCall implementation in gRPC transport.
- *
- * <p>This class is thread-safe.
- *
- * @param <RequestT> call request type
- * @param <ResponseT> call response type
- */
-final class HttpJsonClientCallImpl<RequestT, ResponseT>
-    extends HttpJsonClientCall<RequestT, ResponseT> implements ResultListener {
-  //
-  // A lock to guard the state of this call (and the response stream).
-  //
-  private final Object lock = new Object();
-
-  // An active delivery loop marker.
-  @GuardedBy("lock")
-  private boolean inDelivery = false;
-
-  // A queue to keep "scheduled" calls to HttpJsonClientCall.Listener<ResponseT> in a form of tasks.
-  // It may seem like an overkill, but it exists to implement the following listeners contract:
-  //   - onHeaders() must be called before any onMessage();
-  //   - onClose() must be the last call made, no onMessage() or onHeaders() are allowed after that;
-  //   - while methods on the same listener may be called from different threads they must never be
-  //     called simultaneously;
-  //   - listeners should not be called under the internal lock of the client call to reduce risk of
-  //     deadlocking and minimize time spent under lock;
-  //   - a specialized notifications' dispatcher thread may be used in the future to send
-  //     notifications (not the case right now).
-  @GuardedBy("lock")
-  private final Queue<NotificationTask<ResponseT>> pendingNotifications = new ArrayDeque<>();
-
-  //
-  // Immutable API method-specific data.
-  //
-  private final HttpJsonCallOptions callOptions;
-  private final String endpoint;
-  private final ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor;
-  private final HttpTransport httpTransport;
-  private final Executor executor;
-
-  //
-  // Request-specific data (provided by client code) before we get a response.
-  //
-  @GuardedBy("lock")
-  private HttpJsonMetadata requestHeaders;
-
-  @GuardedBy("lock")
-  private Listener<ResponseT> listener;
-
-  @GuardedBy("lock")
-  private int pendingNumMessages;
-
-  //
-  // Response-specific data (received from server).
-  //
-  @GuardedBy("lock")
-  private HttpRequestRunnable<RequestT, ResponseT> requestRunnable;
-
-  @GuardedBy("lock")
-  private RunnableResult runnableResult;
-
-  @GuardedBy("lock")
-  private ProtoMessageJsonStreamIterator responseStreamIterator;
-
-  @GuardedBy("lock")
-  private boolean closed;
-
-  HttpJsonClientCallImpl(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor,
-      String endpoint,
-      HttpJsonCallOptions callOptions,
-      HttpTransport httpTransport,
-      Executor executor) {
-    this.methodDescriptor = methodDescriptor;
-    this.endpoint = endpoint;
-    this.callOptions = callOptions;
-    this.httpTransport = httpTransport;
-    this.executor = executor;
-    this.closed = false;
-  }
-
-  @Override
-  public void setResult(RunnableResult runnableResult) {
-    Preconditions.checkNotNull(runnableResult);
-    synchronized (lock) {
-      if (closed) {
-        return;
-      }
-      Preconditions.checkState(this.runnableResult == null, "The call result is already set");
-      this.runnableResult = runnableResult;
-      if (runnableResult.getResponseHeaders() != null) {
-        pendingNotifications.offer(
-            new OnHeadersNotificationTask<>(listener, runnableResult.getResponseHeaders()));
-      }
-    }
-
-    // trigger delivery loop if not already running
-    deliver();
-  }
-
-  @Override
-  public void start(Listener<ResponseT> responseListener, HttpJsonMetadata requestHeaders) {
-    Preconditions.checkNotNull(responseListener);
-    Preconditions.checkNotNull(requestHeaders);
-    synchronized (lock) {
-      if (closed) {
-        return;
-      }
-      Preconditions.checkState(this.listener == null, "The call is already started");
-      this.listener = responseListener;
-      this.requestHeaders = requestHeaders;
-    }
-  }
-
-  @Override
-  public void request(int numMessages) {
-    if (numMessages < 0) {
-      throw new IllegalArgumentException("numMessages must be non-negative");
-    }
-    synchronized (lock) {
-      if (closed) {
-        return;
-      }
-      pendingNumMessages += numMessages;
-    }
-
-    // trigger delivery loop if not already running
-    deliver();
-  }
-
-  @Override
-  public void cancel(@Nullable String message, @Nullable Throwable cause) {
-    Throwable actualCause = cause;
-    if (actualCause == null) {
-      actualCause = new CancellationException(message);
-    }
-
-    synchronized (lock) {
-      close(499, message, actualCause, true);
-    }
-
-    // trigger delivery loop if not already running
-    deliver();
-  }
-
-  @Override
-  public void sendMessage(RequestT message) {
-    Preconditions.checkNotNull(message);
-    HttpRequestRunnable<RequestT, ResponseT> localRunnable;
-    synchronized (lock) {
-      if (closed) {
-        return;
-      }
-      Preconditions.checkState(listener != null, "The call hasn't been started");
-      Preconditions.checkState(
-          requestRunnable == null,
-          "The message has already been sent. Bidirectional streaming calls are not supported");
-
-      requestRunnable =
-          new HttpRequestRunnable<>(
-              message,
-              methodDescriptor,
-              endpoint,
-              callOptions,
-              httpTransport,
-              requestHeaders,
-              this);
-      localRunnable = requestRunnable;
-    }
-    executor.execute(localRunnable);
-  }
-
-  @Override
-  public void halfClose() {
-    // no-op for now, as halfClose makes sense only for bidirectional streams.
-  }
-
-  private void deliver() {
-    // A flag stored in method stack space to detect when we enter a delivery loop (regardless if
-    // it is a concurrent thread or a recursive call execution of delivery() method within the same
-    // thread).
-    boolean newActiveDeliveryLoop = true;
-    boolean allMessagesConsumed = false;
-    while (true) {
-      // The try block around listener notification logic. We need to keep this
-      // block inside the loop to make sure that in case onMessage() call throws, we close the
-      // request properly and call onClose() method on listener once eventually (because the
-      // listener can be called only inside this loop).
-      try {
-        // Check if there is only one delivery loop active. Exit if a competing delivery loop
-        // detected (either in a concurrent thread or in a previous recursive call to this method in
-        // the same thread). The last-standing delivery loop will do all the job. Even if something
-        // in this loop throws, the code will first go through this block before exiting the loop to
-        // make sure that the activeDeliveryLoops counter stays correct.
-        //
-        // Note, we must enter the loop before doing the check.
-        synchronized (lock) {
-          if (inDelivery && newActiveDeliveryLoop) {
-            // EXIT delivery loop because another active delivery loop has been detected.
-            break;
-          }
-          newActiveDeliveryLoop = false;
-          inDelivery = true;
-        }
-
-        if (Thread.interrupted()) {
-          // The catch block below will properly cancel the call. Note Thread.interrupted() clears
-          // the interruption flag on this thread, so we don't throw forever.
-          throw new InterruptedException("Message delivery has been interrupted");
-        }
-
-        // All listeners must be called under delivery loop (but outside the lock) to ensure that no
-        // two notifications come simultaneously from two different threads and that we do not go
-        // indefinitely deep in the stack if delivery logic is called recursively via listeners.
-        notifyListeners();
-
-        // The synchronized block around message reading and cancellation notification processing
-        // logic
-        synchronized (lock) {
-          if (allMessagesConsumed) {
-            // allMessagesProcessed was set to true on previous loop iteration. We do it this
-            // way to make sure that notifyListeners() is called in between consuming the last
-            // message in a stream and closing the call.
-            // This is to make sure that onMessage() for the last message in a stream is called
-            // before closing this call, because that last onMessage() listener execution may change
-            // how the call has to be closed (normally or cancelled).
-
-            // Close the call normally.
-            // once close() is called we will never ever enter this again, because `close` flag
-            // will be set to true by the close() method. If the call is already closed, close()
-            // will have no effect.
-            allMessagesConsumed = false;
-            close(
-                runnableResult.getStatusCode(),
-                runnableResult.getTrailers().getStatusMessage(),
-                runnableResult.getTrailers().getException(),
-                false);
-          }
-
-          // Attempt to terminate the delivery loop if:
-          //   `runnableResult == null` => there is no response from the server yet;
-          //   `pendingNumMessages <= 0` => we have already delivered as much as has been asked;
-          //   `closed` => this call has been closed already;
-          if (runnableResult == null || pendingNumMessages <= 0 || closed) {
-            // The loop terminates only when there are no pending notifications left. The check
-            // happens under the lock, so no other thread may add a listener notification task in
-            // the middle of this logic.
-            if (pendingNotifications.isEmpty()) {
-              // EXIT delivery loop because there is no more work left to do. This is expected to be
-              // the only active delivery loop.
-              inDelivery = false;
-              break;
-            } else {
-              // We still have some stuff in notiticationTasksQueue so continue the loop, most
-              // likely we will finally terminate on the next cycle.
-              continue;
-            }
-          }
-          pendingNumMessages--;
-          allMessagesConsumed = consumeMessageFromStream();
-        }
-      } catch (Throwable e) {
-        // Exceptions in message delivery result into cancellation of the call to stay consistent
-        // with other transport implementations.
-        HttpJsonStatusRuntimeException ex =
-            new HttpJsonStatusRuntimeException(499, "Exception in message delivery", e);
-        // If we are already closed the exception will be swallowed, which is the best thing we
-        // can do in such an unlikely situation (otherwise we would stay forever in the delivery
-        // loop).
-        synchronized (lock) {
-          // Close the call immediately marking it cancelled. If already closed close() will have no
-          // effect.
-          close(ex.getStatusCode(), ex.getMessage(), ex, true);
-        }
-      }
-    }
-  }
-
-  private void notifyListeners() {
-    while (true) {
-      NotificationTask<ResponseT> notification;
-      synchronized (lock) {
-        if (pendingNotifications.isEmpty()) {
-          return;
-        }
-        notification = pendingNotifications.poll();
-      }
-      notification.call();
-    }
-  }
-
-  @GuardedBy("lock")
-  private boolean consumeMessageFromStream() throws IOException {
-    if (runnableResult.getTrailers().getException() != null
-        || runnableResult.getResponseContent() == null) {
-      // Server returned an error, no messages to process. This will result into closing a call with
-      // an error.
-      return true;
-    }
-
-    boolean allMessagesConsumed;
-    Reader responseReader;
-    if (methodDescriptor.getType() == MethodType.SERVER_STREAMING) {
-      // Lazily initialize responseStreamIterator in case if it is a server steraming response
-      if (responseStreamIterator == null) {
-        responseStreamIterator =
-            new ProtoMessageJsonStreamIterator(
-                new InputStreamReader(runnableResult.getResponseContent(), StandardCharsets.UTF_8));
-      }
-      if (responseStreamIterator.hasNext()) {
-        responseReader = responseStreamIterator.next();
-      } else {
-        return true;
-      }
-      // To make sure that the call will be closed immediately once we read the last
-      // message from the response (otherwise we would need to wait for another request(1)
-      // from the client to check if there is anything else left in the stream).
-      allMessagesConsumed = !responseStreamIterator.hasNext();
-    } else {
-      responseReader =
-          new InputStreamReader(runnableResult.getResponseContent(), StandardCharsets.UTF_8);
-      // Unary calls have only one message in their response, so we should be ready to close
-      // immediately after delivering a single response message.
-      allMessagesConsumed = true;
-    }
-
-    ResponseT message =
-        methodDescriptor.getResponseParser().parse(responseReader, callOptions.getTypeRegistry());
-    pendingNotifications.offer(new OnMessageNotificationTask<>(listener, message));
-
-    return allMessagesConsumed;
-  }
-
-  @GuardedBy("lock")
-  private void close(
-      int statusCode, String message, Throwable cause, boolean terminateImmediatelly) {
-    try {
-      if (closed) {
-        return;
-      }
-      closed = true;
-      // Best effort task cancellation (to not be confused with task's thread interruption).
-      // If the task is in blocking I/O waiting for the server response, it will keep waiting for
-      // the response from the server, but once response is received the task will exit silently.
-      // If the task has already completed, this call has no effect.
-      if (requestRunnable != null) {
-        requestRunnable.cancel();
-        requestRunnable = null;
-      }
-
-      HttpJsonMetadata.Builder meatadaBuilder = HttpJsonMetadata.newBuilder();
-      if (runnableResult != null && runnableResult.getTrailers() != null) {
-        meatadaBuilder = runnableResult.getTrailers().toBuilder();
-      }
-      meatadaBuilder.setException(cause);
-      meatadaBuilder.setStatusMessage(message);
-      if (responseStreamIterator != null) {
-        responseStreamIterator.close();
-      }
-      if (runnableResult != null && runnableResult.getResponseContent() != null) {
-        runnableResult.getResponseContent().close();
-      }
-
-      // onClose() suppresses all other pending notifications.
-      // there should be no place in the code which inserts something in this queue before checking
-      // the `closed` flag under the lock and refusing to insert anything if `closed == true`.
-      if (terminateImmediatelly) {
-        // This usually means we are cancelling the call before processing the response in full.
-        // It may happen if a user explicitly cancels the call or in response to an unexpected
-        // exception either from server or a call listener execution.
-        pendingNotifications.clear();
-      }
-
-      pendingNotifications.offer(
-          new OnCloseNotificationTask<>(listener, statusCode, meatadaBuilder.build()));
-
-    } catch (Throwable e) {
-      // suppress stream closing exceptions in favor of the actual call closing cause. This method
-      // should not throw, otherwise we may stuck in an infinite loop of exception processing.
-    }
-  }
-
-  //
-  // Listener notification tasks. Each class simply calls only one specific method on the Listener
-  // interface, and to do so it also stores tha parameters needed to make the all.
-  //
-  private abstract static class NotificationTask<ResponseT> {
-    private final Listener<ResponseT> listener;
-
-    NotificationTask(Listener<ResponseT> listener) {
-      this.listener = listener;
-    }
-
-    protected Listener<ResponseT> getListener() {
-      return listener;
-    }
-
-    abstract void call();
-  }
-
-  private static class OnHeadersNotificationTask<ResponseT> extends NotificationTask<ResponseT> {
-    private final HttpJsonMetadata responseHeaders;
-
-    OnHeadersNotificationTask(Listener<ResponseT> listener, HttpJsonMetadata responseHeaders) {
-      super(listener);
-      this.responseHeaders = responseHeaders;
-    }
-
-    public void call() {
-      getListener().onHeaders(responseHeaders);
-    }
-  }
-
-  private static class OnMessageNotificationTask<ResponseT> extends NotificationTask<ResponseT> {
-    private final ResponseT message;
-
-    OnMessageNotificationTask(Listener<ResponseT> listener, ResponseT message) {
-      super(listener);
-      this.message = message;
-    }
-
-    public void call() {
-      getListener().onMessage(message);
-    }
-  }
-
-  private static class OnCloseNotificationTask<ResponseT> extends NotificationTask<ResponseT> {
-    private final int statusCode;
-    private final HttpJsonMetadata trailers;
-
-    OnCloseNotificationTask(
-        Listener<ResponseT> listener, int statusCode, HttpJsonMetadata trailers) {
-      super(listener);
-      this.statusCode = statusCode;
-      this.trailers = trailers;
-    }
-
-    public void call() {
-      getListener().onClose(statusCode, trailers);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCalls.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCalls.java
deleted file mode 100644
index 9512537cd..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientCalls.java
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import javax.annotation.Nonnull;
-import org.threeten.bp.Instant;
-
-/**
- * {@code HttpJsonClientCalls} creates a new {@code HttpJsonClientCAll} from the given call context.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonClientCalls {
-  private static final Logger LOGGER = Logger.getLogger(HttpJsonClientCalls.class.getName());
-
-  public static <RequestT, ResponseT> HttpJsonClientCall<RequestT, ResponseT> newCall(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, ApiCallContext context) {
-
-    HttpJsonCallContext httpJsonContext = HttpJsonCallContext.createDefault().nullToSelf(context);
-
-    // Try to convert the timeout into a deadline and use it if it occurs before the actual deadline
-    if (httpJsonContext.getTimeout() != null) {
-      @Nonnull Instant newDeadline = Instant.now().plus(httpJsonContext.getTimeout());
-      HttpJsonCallOptions callOptions = httpJsonContext.getCallOptions();
-      if (callOptions.getDeadline() == null || newDeadline.isBefore(callOptions.getDeadline())) {
-        callOptions = callOptions.toBuilder().setDeadline(newDeadline).build();
-        httpJsonContext = httpJsonContext.withCallOptions(callOptions);
-      }
-    }
-
-    // TODO: add headers interceptor logic
-    return httpJsonContext.getChannel().newCall(methodDescriptor, httpJsonContext.getCallOptions());
-  }
-
-  static <RequestT, ResponseT> ApiFuture<ResponseT> eagerFutureUnaryCall(
-      HttpJsonClientCall<RequestT, ResponseT> clientCall, RequestT request) {
-    // Start the call
-    HttpJsonFuture<ResponseT> future = new HttpJsonFuture<>(clientCall);
-    clientCall.start(new FutureListener<>(future), HttpJsonMetadata.newBuilder().build());
-
-    // Send the request
-    try {
-      clientCall.sendMessage(request);
-      clientCall.halfClose();
-      // Request an extra message to detect misconfigured servers
-      clientCall.request(2);
-    } catch (Throwable sendError) {
-      // Cancel if anything goes wrong
-      try {
-        clientCall.cancel(null, sendError);
-      } catch (Throwable cancelError) {
-        LOGGER.log(Level.SEVERE, "Error encountered while closing it", sendError);
-      }
-
-      throw sendError;
-    }
-
-    return future;
-  }
-
-  private static class HttpJsonFuture<T> extends AbstractApiFuture<T> {
-    private final HttpJsonClientCall<?, T> call;
-
-    private HttpJsonFuture(HttpJsonClientCall<?, T> call) {
-      this.call = call;
-    }
-
-    @Override
-    protected void interruptTask() {
-      call.cancel("HttpJsonFuture was cancelled", null);
-    }
-
-    @Override
-    public boolean set(T value) {
-      return super.set(value);
-    }
-
-    @Override
-    public boolean setException(Throwable throwable) {
-      return super.setException(throwable);
-    }
-  }
-
-  private static class FutureListener<T> extends HttpJsonClientCall.Listener<T> {
-    private final HttpJsonFuture<T> future;
-
-    private FutureListener(HttpJsonFuture<T> future) {
-      this.future = future;
-    }
-
-    @Override
-    public void onMessage(T message) {
-      if (!future.set(message)) {
-        throw new IllegalStateException("More than one value received for unary call");
-      }
-    }
-
-    @Override
-    public void onClose(int statusCode, HttpJsonMetadata trailers) {
-      if (!future.isDone()) {
-        if (trailers == null || trailers.getException() == null) {
-          future.setException(
-              new HttpJsonStatusRuntimeException(
-                  statusCode,
-                  "Exception during a client call closure",
-                  new NullPointerException(
-                      "Both response message and response exception were null")));
-        } else {
-          future.setException(trailers.getException());
-        }
-      } else if (statusCode < 200 || statusCode >= 400) {
-        LOGGER.log(
-            Level.WARNING, "Received error for unary call after receiving a successful response");
-      }
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientInterceptor.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientInterceptor.java
deleted file mode 100644
index 446fe09f2..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonClientInterceptor.java
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-
-/**
- * Interface for intercepting outgoing calls before they are dispatched by a {@link
- * HttpJsonChannel}.
- *
- * <p>The interceptor may be called for multiple {@link HttpJsonClientCall calls} by one or more
- * threads without completing the previous ones first. The implementations must be thread-safe.
- */
-@BetaApi
-public interface HttpJsonClientInterceptor {
-  /**
-   * Intercept {@link HttpJsonClientCall} creation by the {@code next} {@link HttpJsonChannel}.
-   *
-   * @param method the remote method to be called
-   * @param callOptions the runtime options to be applied to this call
-   * @param next the channel which is being intercepted
-   * @return the call object for the remote operation, never {@code null}
-   */
-  <ReqT, RespT> HttpJsonClientCall<ReqT, RespT> interceptCall(
-      ApiMethodDescriptor<ReqT, RespT> method,
-      HttpJsonCallOptions callOptions,
-      HttpJsonChannel next);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectCallable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectCallable.java
deleted file mode 100644
index dd0826dd6..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectCallable.java
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-import com.google.protobuf.TypeRegistry;
-
-/**
- * {@code HttpJsonDirectCallable} creates HTTP calls.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonDirectCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final ApiMethodDescriptor<RequestT, ResponseT> descriptor;
-  private final TypeRegistry typeRegistry;
-
-  HttpJsonDirectCallable(ApiMethodDescriptor<RequestT, ResponseT> descriptor) {
-    this(descriptor, null);
-  }
-
-  HttpJsonDirectCallable(
-      ApiMethodDescriptor<RequestT, ResponseT> descriptor, TypeRegistry typeRegistry) {
-    this.descriptor = descriptor;
-    this.typeRegistry = typeRegistry;
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    Preconditions.checkNotNull(request);
-    HttpJsonCallContext context = HttpJsonCallContext.createDefault().nullToSelf(inputContext);
-
-    context =
-        context.withCallOptions(
-            context.getCallOptions().toBuilder().setTypeRegistry(typeRegistry).build());
-
-    HttpJsonClientCall<RequestT, ResponseT> clientCall =
-        HttpJsonClientCalls.newCall(descriptor, context);
-    return HttpJsonClientCalls.eagerFutureUnaryCall(clientCall, request);
-  }
-
-  @Override
-  public String toString() {
-    return String.format("direct(%s)", descriptor);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallable.java
deleted file mode 100644
index ed3bebde3..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallable.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-
-/**
- * {@code HttpJsonDirectServerStreamingCallable} creates server-streaming REST calls.
- *
- * <p>In a chain of {@link ServerStreamingCallable}s this is the innermost callable. It wraps a
- * {@link HttpJsonClientCall} in a {@link StreamController} and the downstream {@link
- * ResponseObserver} in a {@link HttpJsonClientCall.Listener}. This class is implemented to look and
- * behave as similarly as possible to gRPC variant of it.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonDirectServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-
-  private final ApiMethodDescriptor<RequestT, ResponseT> descriptor;
-
-  HttpJsonDirectServerStreamingCallable(ApiMethodDescriptor<RequestT, ResponseT> descriptor) {
-    this.descriptor = descriptor;
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    Preconditions.checkNotNull(request);
-    Preconditions.checkNotNull(responseObserver);
-
-    HttpJsonClientCall<RequestT, ResponseT> call = HttpJsonClientCalls.newCall(descriptor, context);
-    HttpJsonDirectStreamController<RequestT, ResponseT> controller =
-        new HttpJsonDirectStreamController<>(call, responseObserver);
-    controller.start(request);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectStreamController.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectStreamController.java
deleted file mode 100644
index 5f56390f0..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonDirectStreamController.java
+++ /dev/null
@@ -1,126 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.CancellationException;
-
-/**
- * Wraps a HttpJsonClientCall in a {@link StreamController}. It feeds events to a {@link
- * ResponseObserver} and allows for back pressure.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonDirectStreamController<RequestT, ResponseT> implements StreamController {
-  private final HttpJsonClientCall<RequestT, ResponseT> clientCall;
-  private final ResponseObserver<ResponseT> responseObserver;
-  private volatile boolean hasStarted;
-  private volatile boolean autoflowControl = true;
-  private volatile int numRequested;
-  private volatile CancellationException cancellationException;
-
-  HttpJsonDirectStreamController(
-      HttpJsonClientCall<RequestT, ResponseT> clientCall,
-      ResponseObserver<ResponseT> responseObserver) {
-    this.clientCall = clientCall;
-    this.responseObserver = responseObserver;
-  }
-
-  @Override
-  public void cancel() {
-    cancellationException = new CancellationException("User cancelled stream");
-    clientCall.cancel(null, cancellationException);
-  }
-
-  @Override
-  public void disableAutoInboundFlowControl() {
-    Preconditions.checkState(
-        !hasStarted, "Can't disable automatic flow control after the stream has started.");
-    autoflowControl = false;
-  }
-
-  @Override
-  public void request(int count) {
-    Preconditions.checkState(!autoflowControl, "Autoflow control is enabled.");
-
-    // Buffer the requested count in case the consumer requested responses in the onStart()
-    if (!hasStarted) {
-      numRequested += count;
-    } else {
-      clientCall.request(count);
-    }
-  }
-
-  void start(RequestT request) {
-    responseObserver.onStart(this);
-    this.hasStarted = true;
-    clientCall.start(new ResponseObserverAdapter(), HttpJsonMetadata.newBuilder().build());
-
-    if (autoflowControl) {
-      clientCall.request(1);
-    } else if (numRequested > 0) {
-      clientCall.request(numRequested);
-    }
-
-    clientCall.sendMessage(request);
-  }
-
-  private class ResponseObserverAdapter extends HttpJsonClientCall.Listener<ResponseT> {
-    /**
-     * Notifies the outerObserver of the new message and if automatic flow control is enabled,
-     * requests the next message. Any errors raised by the outerObserver will be bubbled up to GRPC,
-     * which cancel the ClientCall and close this listener.
-     *
-     * @param message The new message.
-     */
-    @Override
-    public void onMessage(ResponseT message) {
-      responseObserver.onResponse(message);
-
-      if (autoflowControl) {
-        clientCall.request(1);
-      }
-    }
-
-    @Override
-    public void onClose(int statusCode, HttpJsonMetadata trailers) {
-      if (statusCode >= 200 && statusCode < 300) {
-        responseObserver.onComplete();
-      } else if (cancellationException != null) {
-        // Intercept cancellations and replace with the top level cause
-        responseObserver.onError(cancellationException);
-      } else {
-        responseObserver.onError(trailers.getException());
-      }
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionCallable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionCallable.java
deleted file mode 100644
index ede9ce343..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionCallable.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-import java.util.Set;
-import java.util.concurrent.CancellationException;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonExceptionCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final HttpJsonApiExceptionFactory exceptionFactory;
-
-  HttpJsonExceptionCallable(
-      UnaryCallable<RequestT, ResponseT> callable, Set<StatusCode.Code> retryableCodes) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.exceptionFactory = new HttpJsonApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    HttpJsonCallContext context = HttpJsonCallContext.createDefault().nullToSelf(inputContext);
-    ApiFuture<ResponseT> innerCallFuture = callable.futureCall(request, context);
-    ExceptionTransformingFuture transformingFuture =
-        new ExceptionTransformingFuture(innerCallFuture);
-    ApiFutures.addCallback(innerCallFuture, transformingFuture, directExecutor());
-    return transformingFuture;
-  }
-
-  private class ExceptionTransformingFuture extends AbstractApiFuture<ResponseT>
-      implements ApiFutureCallback<ResponseT> {
-    private final ApiFuture<ResponseT> innerCallFuture;
-    private volatile boolean cancelled = false;
-
-    public ExceptionTransformingFuture(ApiFuture<ResponseT> innerCallFuture) {
-      this.innerCallFuture = innerCallFuture;
-    }
-
-    @Override
-    protected void interruptTask() {
-      cancelled = true;
-      innerCallFuture.cancel(true);
-    }
-
-    @Override
-    public void onSuccess(ResponseT r) {
-      super.set(r);
-    }
-
-    @Override
-    public void onFailure(Throwable throwable) {
-      if (throwable instanceof CancellationException && cancelled) {
-        // this just circled around, so ignore.
-        return;
-      }
-      setException(exceptionFactory.create(throwable));
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionResponseObserver.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionResponseObserver.java
deleted file mode 100644
index 0264a33f0..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionResponseObserver.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StateCheckingResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import java.util.concurrent.CancellationException;
-
-/** Package-private for internal use. */
-class HttpJsonExceptionResponseObserver<ResponseT>
-    extends StateCheckingResponseObserver<ResponseT> {
-  private final ResponseObserver<ResponseT> innerObserver;
-  private volatile CancellationException cancellationException;
-  private final HttpJsonApiExceptionFactory exceptionFactory;
-
-  public HttpJsonExceptionResponseObserver(
-      ResponseObserver<ResponseT> innerObserver, HttpJsonApiExceptionFactory exceptionFactory) {
-    this.innerObserver = innerObserver;
-    this.exceptionFactory = exceptionFactory;
-  }
-
-  @Override
-  protected void onStartImpl(final StreamController controller) {
-    innerObserver.onStart(
-        new StreamController() {
-          @Override
-          public void cancel() {
-            cancellationException = new CancellationException("User cancelled stream");
-            controller.cancel();
-          }
-
-          @Override
-          public void disableAutoInboundFlowControl() {
-            controller.disableAutoInboundFlowControl();
-          }
-
-          @Override
-          public void request(int count) {
-            controller.request(count);
-          }
-        });
-  }
-
-  @Override
-  protected void onResponseImpl(ResponseT response) {
-    innerObserver.onResponse(response);
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    if (cancellationException != null) {
-      t = cancellationException;
-    } else {
-      t = exceptionFactory.create(t);
-    }
-    innerObserver.onError(t);
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    innerObserver.onComplete();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionServerStreamingCallable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionServerStreamingCallable.java
deleted file mode 100644
index 7c82b2fb1..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonExceptionServerStreamingCallable.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import java.util.Set;
-
-/**
- * Transforms all {@code Throwable}s thrown during a rest call into an instance of {@link
- * ApiException}.
- *
- * <p>Package-private for internal use.
- */
-class HttpJsonExceptionServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-  private final ServerStreamingCallable<RequestT, ResponseT> inner;
-  private final HttpJsonApiExceptionFactory exceptionFactory;
-
-  public HttpJsonExceptionServerStreamingCallable(
-      ServerStreamingCallable<RequestT, ResponseT> inner, Set<Code> retryableCodes) {
-    this.inner = inner;
-    this.exceptionFactory = new HttpJsonApiExceptionFactory(retryableCodes);
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-    inner.call(
-        request,
-        new HttpJsonExceptionResponseObserver<>(responseObserver, exceptionFactory),
-        context);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancer.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancer.java
deleted file mode 100644
index 897fecf8f..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancer.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpHeaders;
-import com.google.api.core.BetaApi;
-
-/** Interface for functionality to enhance headers for an http-json call. */
-@BetaApi
-public interface HttpJsonHeaderEnhancer {
-  void enhance(HttpHeaders headers);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancers.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancers.java
deleted file mode 100644
index 3d3deda30..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderEnhancers.java
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpHeaders;
-import com.google.api.core.BetaApi;
-
-/** Utility class that creates instances of {@link HttpJsonHeaderEnhancer}. */
-@BetaApi
-public class HttpJsonHeaderEnhancers {
-
-  private HttpJsonHeaderEnhancers() {}
-
-  public static HttpJsonHeaderEnhancer create(final String key, final String value) {
-    return new HttpJsonHeaderEnhancer() {
-      @Override
-      public void enhance(HttpHeaders headers) {
-        HttpHeadersUtils.setHeader(headers, key, value);
-      }
-    };
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderInterceptor.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderInterceptor.java
deleted file mode 100644
index 0f58181cb..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonHeaderInterceptor.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.httpjson.ForwardingHttpJsonClientCall.SimpleForwardingHttpJsonClientCall;
-import com.google.common.collect.ImmutableMap;
-import java.util.Map;
-
-/**
- * An interceptor to handle custom headers.
- *
- * <p>Package-private for internal usage.
- */
-class HttpJsonHeaderInterceptor implements HttpJsonClientInterceptor {
-
-  private final Map<String, String> staticHeaders;
-
-  public HttpJsonHeaderInterceptor(Map<String, String> staticHeaders) {
-    this.staticHeaders = staticHeaders;
-  }
-
-  @Override
-  public <ReqT, RespT> HttpJsonClientCall<ReqT, RespT> interceptCall(
-      ApiMethodDescriptor<ReqT, RespT> method,
-      final HttpJsonCallOptions callOptions,
-      HttpJsonChannel next) {
-    HttpJsonClientCall<ReqT, RespT> call = next.newCall(method, callOptions);
-    return new SimpleForwardingHttpJsonClientCall<ReqT, RespT>(call) {
-      @Override
-      public void start(
-          HttpJsonClientCall.Listener<RespT> responseListener, HttpJsonMetadata headers) {
-        Map<String, Object> mergedHeaders =
-            ImmutableMap.<String, Object>builder()
-                .putAll(headers.getHeaders())
-                .putAll(staticHeaders)
-                .build();
-
-        super.start(responseListener, headers.toBuilder().setHeaders(mergedHeaders).build());
-      }
-    };
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonInterceptorProvider.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonInterceptorProvider.java
deleted file mode 100644
index 4c5ddb475..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonInterceptorProvider.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import java.util.List;
-
-/** Provider of custom REST ClientInterceptors. */
-@BetaApi(
-    "The surface for adding custom interceptors is not stable yet and may change in the future.")
-public interface HttpJsonInterceptorProvider {
-
-  /**
-   * Get the list of client interceptors.
-   *
-   * @return interceptors
-   */
-  List<HttpJsonClientInterceptor> getInterceptors();
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonLongRunningClient.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonLongRunningClient.java
deleted file mode 100644
index 55bb5733c..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonLongRunningClient.java
+++ /dev/null
@@ -1,90 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.TranslatingUnaryCallable;
-import com.google.api.gax.rpc.UnaryCallable;
-
-/**
- * Implementation of LongRunningClient based on REST transport.
- *
- * <p>Public for technical reasons. For internal use only.
- */
-@InternalApi
-public class HttpJsonLongRunningClient<RequestT, OperationT> implements LongRunningClient {
-
-  private final UnaryCallable<RequestT, OperationT> operationCallable;
-  private final OperationSnapshotFactory<RequestT, OperationT> operationSnapshotFactory;
-  private final PollingRequestFactory<RequestT> pollingRequestFactory;
-
-  public HttpJsonLongRunningClient(
-      UnaryCallable<RequestT, OperationT> operationCallable,
-      OperationSnapshotFactory<RequestT, OperationT> operationSnapshotFactory,
-      PollingRequestFactory<RequestT> pollingRequestFactory) {
-    this.operationCallable = operationCallable;
-    this.operationSnapshotFactory = operationSnapshotFactory;
-    this.pollingRequestFactory = pollingRequestFactory;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public UnaryCallable<String, OperationSnapshot> getOperationCallable() {
-    return TranslatingUnaryCallable.create(
-        operationCallable,
-        new ApiFunction<String, RequestT>() {
-          @Override
-          public RequestT apply(String id) {
-            return pollingRequestFactory.create(id);
-          }
-        },
-        new ApiFunction<OperationT, OperationSnapshot>() {
-          @Override
-          public OperationSnapshot apply(OperationT operation) {
-            return operationSnapshotFactory.create(null, operation);
-          }
-        });
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public UnaryCallable<String, Void> cancelOperationCallable() {
-    return null;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public UnaryCallable<String, Void> deleteOperationCallable() {
-    return null;
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonMetadata.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonMetadata.java
deleted file mode 100644
index 9fef6db5c..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonMetadata.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.auto.value.AutoValue;
-import java.util.Collections;
-import java.util.Map;
-import javax.annotation.Nullable;
-
-@AutoValue
-@BetaApi
-@InternalExtensionOnly
-public abstract class HttpJsonMetadata {
-  public abstract Map<String, Object> getHeaders();
-
-  @Nullable
-  public abstract String getStatusMessage();
-
-  @Nullable
-  public abstract Throwable getException();
-
-  public abstract Builder toBuilder();
-
-  public static HttpJsonMetadata.Builder newBuilder() {
-    return new AutoValue_HttpJsonMetadata.Builder().setHeaders(Collections.emptyMap());
-  }
-
-  @AutoValue.Builder
-  abstract static class Builder {
-    abstract Builder setHeaders(Map<String, Object> headers);
-
-    public abstract Builder setStatusMessage(String value);
-
-    public abstract Builder setException(Throwable value);
-
-    abstract HttpJsonMetadata build();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshot.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshot.java
deleted file mode 100644
index 1e616a31a..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshot.java
+++ /dev/null
@@ -1,163 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.longrunning.Operation;
-
-/**
- * Implementation of OperationSnapshot based on REST transport.
- *
- * <p>Public for technical reasons. For internal use only.
- */
-@BetaApi
-@InternalApi
-public class HttpJsonOperationSnapshot implements OperationSnapshot {
-  private final String name;
-  private final Object metadata;
-  private final boolean done;
-  private final Object response;
-  private final StatusCode errorCode;
-  private final String errorMessage;
-
-  private HttpJsonOperationSnapshot(
-      String name,
-      Object metadata,
-      boolean done,
-      Object response,
-      StatusCode errorCode,
-      String errorMessage) {
-    this.name = name;
-    this.metadata = metadata;
-    this.done = done;
-    this.response = response;
-    this.errorCode = errorCode;
-    this.errorMessage = errorMessage;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public String getName() {
-    return this.name;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public Object getMetadata() {
-    return this.metadata;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public boolean isDone() {
-    return done;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public Object getResponse() {
-    return this.response;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public StatusCode getErrorCode() {
-    return this.errorCode;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public String getErrorMessage() {
-    return this.errorMessage;
-  }
-
-  public static HttpJsonOperationSnapshot create(Operation operation) {
-    return newBuilder().setOperation(operation).build();
-  }
-
-  public static Builder newBuilder() {
-    return new HttpJsonOperationSnapshot.Builder();
-  }
-
-  public static class Builder {
-    private String name;
-    private Object metadata;
-    private boolean done;
-    private Object response;
-    private StatusCode errorCode;
-    private String errorMessage;
-
-    public Builder setName(String name) {
-      this.name = name;
-      return this;
-    }
-
-    public Builder setMetadata(Object metadata) {
-      this.metadata = metadata;
-      return this;
-    }
-
-    public Builder setDone(boolean done) {
-      this.done = done;
-      return this;
-    }
-
-    public Builder setResponse(Object response) {
-      this.response = response;
-      return this;
-    }
-
-    public Builder setError(int httpStatus, String errorMessage) {
-      this.errorCode =
-          httpStatus == 0 ? HttpJsonStatusCode.of(Code.OK) : HttpJsonStatusCode.of(httpStatus);
-      this.errorMessage = errorMessage;
-      return this;
-    }
-
-    private Builder setOperation(Operation operation) {
-      this.name = operation.getName();
-      this.done = operation.getDone();
-      this.response = operation.getResponse();
-      this.metadata = operation.getMetadata();
-      this.errorCode =
-          HttpJsonStatusCode.of(com.google.rpc.Code.forNumber(operation.getError().getCode()));
-      this.errorMessage = operation.getError().getMessage();
-      return this;
-    }
-
-    public HttpJsonOperationSnapshot build() {
-      return new HttpJsonOperationSnapshot(name, metadata, done, response, errorCode, errorMessage);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallable.java
deleted file mode 100644
index 58f99064a..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallable.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-
-/**
- * A {@code UnaryCallable} that wraps a UnaryCallable returning an Operation and returns an
- * OperationSnapshot instead.
- *
- * <p>Public for technical reasons. For internal use only.
- */
-@BetaApi
-@InternalApi
-public class HttpJsonOperationSnapshotCallable<RequestT, OperationT>
-    extends UnaryCallable<RequestT, OperationSnapshot> {
-
-  private final UnaryCallable<RequestT, OperationT> innerCallable;
-  private final OperationSnapshotFactory<RequestT, OperationT> operationSnapshotFactory;
-
-  public HttpJsonOperationSnapshotCallable(
-      UnaryCallable<RequestT, OperationT> innerCallable,
-      OperationSnapshotFactory<RequestT, OperationT> operationSnapshotFactory) {
-    this.innerCallable = innerCallable;
-    this.operationSnapshotFactory = operationSnapshotFactory;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public ApiFuture<OperationSnapshot> futureCall(final RequestT request, ApiCallContext context) {
-    return ApiFutures.transform(
-        innerCallable.futureCall(request, context),
-        new ApiFunction<OperationT, OperationSnapshot>() {
-          @Override
-          public OperationSnapshot apply(OperationT operation) {
-            return operationSnapshotFactory.create(request, operation);
-          }
-        },
-        directExecutor());
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusCode.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusCode.java
deleted file mode 100644
index 617496eb5..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusCode.java
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.rpc.StatusCode;
-import java.util.Objects;
-
-/** A failure code specific to an HTTP call. */
-@BetaApi
-@InternalExtensionOnly
-public class HttpJsonStatusCode implements StatusCode {
-  private final int httpStatus;
-  private final Code statusCode;
-
-  /** Creates a new instance with the given status code. */
-  public static HttpJsonStatusCode of(int httpStatus) {
-    return new HttpJsonStatusCode(httpStatus, httpStatusToStatusCode(httpStatus));
-  }
-
-  public static HttpJsonStatusCode of(Code statusCode) {
-    return new HttpJsonStatusCode(statusCode.getHttpStatusCode(), statusCode);
-  }
-
-  public static HttpJsonStatusCode of(com.google.rpc.Code rpcCode) {
-    return HttpJsonStatusCode.of(rpcCodeToStatusCode(rpcCode));
-  }
-
-  static Code rpcCodeToStatusCode(com.google.rpc.Code rpcCode) {
-    switch (rpcCode) {
-      case OK:
-        return Code.OK;
-      case CANCELLED:
-        return Code.CANCELLED;
-      case UNKNOWN:
-        return Code.UNKNOWN;
-      case INVALID_ARGUMENT:
-        return Code.INVALID_ARGUMENT;
-      case DEADLINE_EXCEEDED:
-        return Code.DEADLINE_EXCEEDED;
-      case NOT_FOUND:
-        return Code.NOT_FOUND;
-      case ALREADY_EXISTS:
-        return Code.ALREADY_EXISTS;
-      case PERMISSION_DENIED:
-        return Code.PERMISSION_DENIED;
-      case RESOURCE_EXHAUSTED:
-        return Code.RESOURCE_EXHAUSTED;
-      case FAILED_PRECONDITION:
-        return Code.FAILED_PRECONDITION;
-      case ABORTED:
-        return Code.ABORTED;
-      case OUT_OF_RANGE:
-        return Code.OUT_OF_RANGE;
-      case UNIMPLEMENTED:
-        return Code.UNIMPLEMENTED;
-      case INTERNAL:
-        return Code.INTERNAL;
-      case UNAVAILABLE:
-        return Code.UNAVAILABLE;
-      case DATA_LOSS:
-        return Code.DATA_LOSS;
-      case UNAUTHENTICATED:
-        return Code.UNAUTHENTICATED;
-      default:
-        throw new IllegalArgumentException("Unrecognized rpc code: " + rpcCode);
-    }
-  }
-
-  static Code httpStatusToStatusCode(int httpStatus) {
-    if (200 <= httpStatus && httpStatus < 300) {
-      return Code.OK;
-    } else if (400 <= httpStatus && httpStatus < 500) {
-      switch (httpStatus) {
-        case 400:
-          return Code.INVALID_ARGUMENT;
-        case 401:
-          return Code.UNAUTHENTICATED;
-        case 403:
-          return Code.PERMISSION_DENIED;
-        case 404:
-          return Code.NOT_FOUND;
-        case 409:
-          return Code.ABORTED;
-        case 416:
-          return Code.OUT_OF_RANGE;
-        case 429:
-          return Code.RESOURCE_EXHAUSTED;
-        case 499:
-          return Code.CANCELLED;
-        default:
-          return Code.FAILED_PRECONDITION;
-      }
-    } else if (500 <= httpStatus && httpStatus < 600) {
-      switch (httpStatus) {
-        case 501:
-          return Code.UNIMPLEMENTED;
-        case 503:
-          return Code.UNAVAILABLE;
-        case 504:
-          return Code.DEADLINE_EXCEEDED;
-        default:
-          return Code.INTERNAL;
-      }
-    }
-    return Code.UNKNOWN;
-  }
-
-  @Override
-  public Code getCode() {
-    return statusCode;
-  }
-
-  /** Returns the status code from the http call. */
-  @Override
-  public Integer getTransportCode() {
-    return httpStatus;
-  }
-
-  private HttpJsonStatusCode(int httpStatus, Code statusCode) {
-    this.httpStatus = httpStatus;
-    this.statusCode = statusCode;
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-
-    HttpJsonStatusCode that = (HttpJsonStatusCode) o;
-
-    return Objects.equals(statusCode, that.statusCode);
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(statusCode);
-  }
-
-  @Override
-  public String toString() {
-    return "HttpJsonStatusCode{" + "statusCode=" + statusCode + "}";
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusRuntimeException.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusRuntimeException.java
deleted file mode 100644
index a1b9b1c1b..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStatusRuntimeException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-/**
- * HTTP status code in RuntimeException form, for propagating status code information via
- * exceptions.
- */
-public class HttpJsonStatusRuntimeException extends RuntimeException {
-  private static final long serialVersionUID = -5390915748330242256L;
-
-  private final int statusCode;
-
-  public HttpJsonStatusRuntimeException(int statusCode, String message, Throwable cause) {
-    super(message, cause);
-    this.statusCode = statusCode;
-  }
-
-  public int getStatusCode() {
-    return statusCode;
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStubCallableFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStubCallableFactory.java
deleted file mode 100644
index a12ca89eb..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonStubCallableFactory.java
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-
-public interface HttpJsonStubCallableFactory<
-    OperationT, OperationsStub extends BackgroundResource> {
-
-  /**
-   * Create a callable object with http/json-specific functionality. Designed for use by generated
-   * code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param callSettings {@link UnaryCallSettings} to configure the method-level settings with
-   * @param clientContext {@link ClientContext} to use to connect to the service
-   * @return {@link UnaryCallable} callable object
-   */
-  <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext);
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with
-   * @param clientContext {@link ClientContext} to use to connect to the service
-   * @return {@link UnaryCallable} callable object
-   */
-  <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext);
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
-   *     settings with
-   * @param clientContext {@link ClientContext} to use to connect to the service
-   * @return {@link UnaryCallable} callable object
-   */
-  <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext);
-
-  /**
-   * Creates a callable object that represents a long-running operation. Designed for use by
-   * generated code.
-   *
-   * @param httpJsonCallSettings the http/json call settings
-   * @param operationCallSettings {@link OperationCallSettings} to configure the method-level
-   *     settings with
-   * @param clientContext {@link ClientContext} to use to connect to the service
-   * @param operationsStub opertation stub to use to poll for updates on the Operation
-   * @return {@link OperationCallable} callable object
-   */
-  <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          HttpJsonCallSettings<RequestT, OperationT> httpJsonCallSettings,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          OperationsStub operationsStub);
-
-  /**
-   * Create a server-streaming callable with. Designed for use by generated code.
-   *
-   * @param httpJsonCallSettings the gRPC call settings
-   * @param callSettings {@link StreamingCallSettings} to configure the method-level settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   */
-  default <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-          ServerStreamingCallSettings<RequestT, ResponseT> callSettings,
-          ClientContext clientContext) {
-    return HttpJsonCallableFactory.createServerStreamingCallable(
-        httpJsonCallSettings, callSettings, clientContext);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonTransportChannel.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonTransportChannel.java
deleted file mode 100644
index 355193964..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonTransportChannel.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.auto.value.AutoValue;
-import java.util.concurrent.TimeUnit;
-
-/** Implementation of TransportChannel based on http/json. */
-@AutoValue
-@InternalExtensionOnly
-public abstract class HttpJsonTransportChannel implements TransportChannel {
-
-  /** The name of the Http-JSON transport. */
-  public static String getHttpJsonTransportName() {
-    return "httpjson";
-  }
-
-  @Override
-  public String getTransportName() {
-    return getHttpJsonTransportName();
-  }
-
-  @Override
-  public HttpJsonCallContext getEmptyCallContext() {
-    return HttpJsonCallContext.createDefault();
-  }
-
-  /** The channel in use. */
-  public abstract ManagedHttpJsonChannel getManagedChannel();
-
-  /** The channel in use. */
-  public HttpJsonChannel getChannel() {
-    return getManagedChannel();
-  }
-
-  @Override
-  public void shutdown() {
-    getManagedChannel().shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return getManagedChannel().isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return getManagedChannel().isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    getManagedChannel().shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return getManagedChannel().awaitTermination(duration, unit);
-  }
-
-  @Override
-  public void close() {
-    getManagedChannel().shutdown();
-  }
-
-  public static Builder newBuilder() {
-    return new AutoValue_HttpJsonTransportChannel.Builder();
-  }
-
-  public static HttpJsonTransportChannel create(ManagedHttpJsonChannel channel) {
-    return newBuilder().setManagedChannel(channel).build();
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setManagedChannel(ManagedHttpJsonChannel value);
-
-    public abstract HttpJsonTransportChannel build();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestFormatter.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestFormatter.java
deleted file mode 100644
index a60bf08e9..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestFormatter.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.pathtemplate.PathTemplate;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-
-/** Interface for classes that create parts of HTTP requests from a parameterized message. */
-public interface HttpRequestFormatter<MessageFormatT> {
-  /**
-   * Return a map where each entry is the name of a query param mapped to the values of the param.
-   */
-  Map<String, List<String>> getQueryParamNames(MessageFormatT apiMessage);
-
-  /** Return the serialized inner request body of the given message. */
-  String getRequestBody(MessageFormatT apiMessage);
-
-  /* Return the relative URL path created from the path parameters from the given message. */
-  String getPath(MessageFormatT apiMessage);
-
-  /** Path template for endpoint URL path. */
-  PathTemplate getPathTemplate();
-
-  /** Additional (alternative) path templates for endpoint URL path. */
-  @BetaApi
-  default List<PathTemplate> getAdditionalPathTemplates() {
-    return Collections.emptyList();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestRunnable.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestRunnable.java
deleted file mode 100644
index 2edb4ceb2..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestRunnable.java
+++ /dev/null
@@ -1,299 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.EmptyContent;
-import com.google.api.client.http.GenericUrl;
-import com.google.api.client.http.HttpContent;
-import com.google.api.client.http.HttpMediaType;
-import com.google.api.client.http.HttpMethods;
-import com.google.api.client.http.HttpRequest;
-import com.google.api.client.http.HttpRequestFactory;
-import com.google.api.client.http.HttpResponse;
-import com.google.api.client.http.HttpResponseException;
-import com.google.api.client.http.HttpTransport;
-import com.google.api.client.http.json.JsonHttpContent;
-import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.JsonObjectParser;
-import com.google.api.client.json.gson.GsonFactory;
-import com.google.api.client.util.GenericData;
-import com.google.auth.Credentials;
-import com.google.auth.http.HttpCredentialsAdapter;
-import com.google.auto.value.AutoValue;
-import com.google.common.base.Strings;
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-import org.threeten.bp.Instant;
-
-/** A runnable object that creates and executes an HTTP request. */
-class HttpRequestRunnable<RequestT, ResponseT> implements Runnable {
-  private final RequestT request;
-  private final ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor;
-  private final String endpoint;
-  private final HttpJsonCallOptions httpJsonCallOptions;
-  private final HttpTransport httpTransport;
-  private final HttpJsonMetadata headers;
-  private final ResultListener resultListener;
-
-  private volatile boolean cancelled = false;
-
-  HttpRequestRunnable(
-      RequestT request,
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor,
-      String endpoint,
-      HttpJsonCallOptions httpJsonCallOptions,
-      HttpTransport httpTransport,
-      HttpJsonMetadata headers,
-      ResultListener resultListener) {
-    this.request = request;
-    this.methodDescriptor = methodDescriptor;
-    this.endpoint = endpoint;
-    this.httpJsonCallOptions = httpJsonCallOptions;
-    this.httpTransport = httpTransport;
-    this.headers = headers;
-    this.resultListener = resultListener;
-  }
-
-  // Best effort cancellation without guarantees.
-  // It will check if the task cancelled before each three sequential potentially time-consuming
-  // operations:
-  //   - request construction;
-  //   - request execution (the most time consuming, taking);
-  //   - response construction.
-  void cancel() {
-    cancelled = true;
-  }
-
-  @Override
-  public void run() {
-    HttpResponse httpResponse = null;
-    RunnableResult.Builder result = RunnableResult.builder();
-    HttpJsonMetadata.Builder trailers = HttpJsonMetadata.newBuilder();
-    HttpRequest httpRequest = null;
-    try {
-      // Check if already cancelled before even creating a request
-      if (cancelled) {
-        return;
-      }
-      httpRequest = createHttpRequest();
-      // Check if already cancelled before sending the request;
-      if (cancelled) {
-        return;
-      }
-
-      httpResponse = httpRequest.execute();
-
-      // Check if already cancelled before sending the request;
-      if (cancelled) {
-        httpResponse.disconnect();
-        return;
-      }
-      result.setResponseHeaders(
-          HttpJsonMetadata.newBuilder().setHeaders(httpResponse.getHeaders()).build());
-      result.setStatusCode(httpResponse.getStatusCode());
-      result.setResponseContent(httpResponse.getContent());
-      trailers.setStatusMessage(httpResponse.getStatusMessage());
-    } catch (HttpResponseException e) {
-      result.setStatusCode(e.getStatusCode());
-      result.setResponseHeaders(HttpJsonMetadata.newBuilder().setHeaders(e.getHeaders()).build());
-      result.setResponseContent(
-          e.getContent() != null
-              ? new ByteArrayInputStream(e.getContent().getBytes(StandardCharsets.UTF_8))
-              : null);
-      trailers.setStatusMessage(e.getStatusMessage());
-      trailers.setException(e);
-    } catch (Throwable e) {
-      if (httpResponse != null) {
-        trailers.setStatusMessage(httpResponse.getStatusMessage());
-        result.setStatusCode(httpResponse.getStatusCode());
-      } else {
-        result.setStatusCode(400);
-      }
-      trailers.setException(e);
-    } finally {
-      if (!cancelled) {
-        resultListener.setResult(result.setTrailers(trailers.build()).build());
-      }
-    }
-  }
-
-  HttpRequest createHttpRequest() throws IOException {
-    GenericData tokenRequest = new GenericData();
-
-    HttpRequestFormatter<RequestT> requestFormatter = methodDescriptor.getRequestFormatter();
-
-    HttpRequestFactory requestFactory;
-    Credentials credentials = httpJsonCallOptions.getCredentials();
-    if (credentials != null) {
-      requestFactory = httpTransport.createRequestFactory(new HttpCredentialsAdapter(credentials));
-    } else {
-      requestFactory = httpTransport.createRequestFactory();
-    }
-
-    JsonFactory jsonFactory = GsonFactory.getDefaultInstance();
-    // Create HTTP request body.
-    String requestBody = requestFormatter.getRequestBody(request);
-    HttpContent jsonHttpContent;
-    if (!Strings.isNullOrEmpty(requestBody)) {
-      jsonFactory.createJsonParser(requestBody).parse(tokenRequest);
-      jsonHttpContent =
-          new JsonHttpContent(jsonFactory, tokenRequest)
-              .setMediaType((new HttpMediaType("application/json")));
-    } else {
-      // Force underlying HTTP lib to set Content-Length header to avoid 411s.
-      // See EmptyContent.java.
-      jsonHttpContent = new EmptyContent();
-    }
-
-    // Populate URL path and query parameters.
-    String normalizedEndpoint = normalizeEndpoint(endpoint);
-    GenericUrl url = new GenericUrl(normalizedEndpoint + requestFormatter.getPath(request));
-    Map<String, List<String>> queryParams = requestFormatter.getQueryParamNames(request);
-    for (Entry<String, List<String>> queryParam : queryParams.entrySet()) {
-      if (queryParam.getValue() != null) {
-        url.set(queryParam.getKey(), queryParam.getValue());
-      }
-    }
-
-    HttpRequest httpRequest = buildRequest(requestFactory, url, jsonHttpContent);
-
-    Instant deadline = httpJsonCallOptions.getDeadline();
-    if (deadline != null) {
-      long readTimeout = Duration.between(Instant.now(), deadline).toMillis();
-      if (httpRequest.getReadTimeout() > 0
-          && httpRequest.getReadTimeout() < readTimeout
-          && readTimeout < Integer.MAX_VALUE) {
-        httpRequest.setReadTimeout((int) readTimeout);
-      }
-    }
-
-    for (Map.Entry<String, Object> entry : headers.getHeaders().entrySet()) {
-      HttpHeadersUtils.setHeader(
-          httpRequest.getHeaders(), entry.getKey(), (String) entry.getValue());
-    }
-
-    httpRequest.setParser(new JsonObjectParser(jsonFactory));
-
-    return httpRequest;
-  }
-
-  private HttpRequest buildRequest(
-      HttpRequestFactory requestFactory, GenericUrl url, HttpContent jsonHttpContent)
-      throws IOException {
-    // A workaround to support PATCH request. This assumes support of "X-HTTP-Method-Override"
-    // header on the server side, which GCP services usually do.
-    //
-    // Long story short, the problems is as follows: gax-httpjson depends on NetHttpTransport class
-    // from google-http-client, which depends on JDK standard java.net.HttpUrlConnection, which does
-    // not support PATCH http method.
-    //
-    // It is a won't fix for JDK8: https://bugs.openjdk.java.net/browse/JDK-8207840.
-    // A corresponding google-http-client issue:
-    // https://github.com/googleapis/google-http-java-client/issues/167
-    //
-    // In JDK11 there is java.net.http.HttpRequest with PATCH method support but, gax-httpjson must
-    // remain compatible with Java 8.
-    //
-    // Using "X-HTTP-Method-Override" header is probably the cleanest way to fix it. Other options
-    // would be: hideous reflection hacks (not a safe option in a generic library, which
-    // gax-httpjson is), writing own implementation of HttpUrlConnection (fragile and a lot of
-    // work), depending on v2.ApacheHttpTransport (it has many extra dependencies, does not support
-    // mtls etc).
-    String actualHttpMethod = methodDescriptor.getHttpMethod();
-    String originalHttpMethod = actualHttpMethod;
-    if (HttpMethods.PATCH.equals(actualHttpMethod)) {
-      actualHttpMethod = HttpMethods.POST;
-    }
-    HttpRequest httpRequest = requestFactory.buildRequest(actualHttpMethod, url, jsonHttpContent);
-    if (originalHttpMethod != null && !originalHttpMethod.equals(actualHttpMethod)) {
-      HttpHeadersUtils.setHeader(
-          httpRequest.getHeaders(), "X-HTTP-Method-Override", originalHttpMethod);
-    }
-    return httpRequest;
-  }
-
-  // This will be frequently executed, so avoiding using regexps if not necessary.
-  private String normalizeEndpoint(String rawEndpoint) {
-    String normalized = rawEndpoint;
-    // Set protocol as https by default if not set explicitly
-    if (!normalized.contains("://")) {
-      normalized = "https://" + normalized;
-    }
-
-    if (normalized.charAt(normalized.length() - 1) != '/') {
-      normalized += '/';
-    }
-
-    return normalized;
-  }
-
-  @FunctionalInterface
-  interface ResultListener {
-    void setResult(RunnableResult result);
-  }
-
-  @AutoValue
-  abstract static class RunnableResult {
-    @Nullable
-    abstract HttpJsonMetadata getResponseHeaders();
-
-    abstract int getStatusCode();
-
-    @Nullable
-    abstract InputStream getResponseContent();
-
-    abstract HttpJsonMetadata getTrailers();
-
-    public static Builder builder() {
-      return new AutoValue_HttpRequestRunnable_RunnableResult.Builder();
-    }
-
-    @AutoValue.Builder
-    public abstract static class Builder {
-
-      public abstract Builder setResponseHeaders(HttpJsonMetadata newResponseHeaders);
-
-      public abstract Builder setStatusCode(int newStatusCode);
-
-      public abstract Builder setResponseContent(InputStream newResponseContent);
-
-      public abstract Builder setTrailers(HttpJsonMetadata newTrailers);
-
-      public abstract RunnableResult build();
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpResponseParser.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpResponseParser.java
deleted file mode 100644
index b2c3d5fc8..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpResponseParser.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.InternalApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.protobuf.TypeRegistry;
-import java.io.InputStream;
-import java.io.Reader;
-
-/** Interface for classes that parse parts of HTTP responses into the parameterized message type. */
-@InternalExtensionOnly
-public interface HttpResponseParser<MessageFormatT> {
-
-  /**
-   * Parse the http body content JSON stream into the MessageFormatT.
-   *
-   * @param httpContent the body of an HTTP response
-   * @throws RestSerializationException if failed to parse the {@code httpContent} to a valid {@code
-   *     MessageFormatT}
-   */
-  MessageFormatT parse(InputStream httpContent);
-
-  /**
-   * Parse the http body content JSON stream into the MessageFormatT.
-   *
-   * @param httpContent the body of an HTTP response, represented as an {@link InputStream}
-   * @param registry type registry with Any fields descriptors
-   * @throws RestSerializationException if failed to parse the {@code httpContent} to a valid {@code
-   *     MessageFormatT}
-   */
-  MessageFormatT parse(InputStream httpContent, TypeRegistry registry);
-
-  /**
-   * Parse the http body content JSON reader into the MessageFormatT.
-   *
-   * @param httpContent the body of an HTTP response, represented as a {@link Reader}
-   * @param registry type registry with Any fields descriptors
-   * @throws RestSerializationException if failed to parse the {@code httpContent} to a valid {@code
-   *     MessageFormatT}
-   */
-  MessageFormatT parse(Reader httpContent, TypeRegistry registry);
-
-  /**
-   * Serialize an object into an HTTP body, which is written out to output.
-   *
-   * @param response the object to serialize
-   * @throws RestSerializationException if failed to serialize {@code response} to a valid {@code
-   *     String} representation
-   */
-  @InternalApi
-  String serialize(MessageFormatT response);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProvider.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProvider.java
deleted file mode 100644
index 57b0ff128..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProvider.java
+++ /dev/null
@@ -1,317 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpTransport;
-import com.google.api.client.http.javanet.NetHttpTransport;
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.rpc.FixedHeaderProvider;
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.auth.Credentials;
-import com.google.common.annotations.VisibleForTesting;
-import java.io.IOException;
-import java.security.GeneralSecurityException;
-import java.security.KeyStore;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-
-/**
- * InstantiatingHttpJsonChannelProvider is a TransportChannelProvider which constructs a {@link
- * ManagedHttpJsonChannel} with a number of configured inputs every time getChannel(...) is called.
- * These inputs include a port, a service address, and credentials.
- *
- * <p>The credentials can either be supplied directly (by providing a FixedCredentialsProvider to
- * Builder.setCredentialsProvider()) or acquired implicitly from Application Default Credentials (by
- * providing a GoogleCredentialsProvider to Builder.setCredentialsProvider()).
- *
- * <p>The client lib header and generator header values are used to form a value that goes into the
- * http header of requests to the service.
- */
-@BetaApi
-@InternalExtensionOnly
-public final class InstantiatingHttpJsonChannelProvider implements TransportChannelProvider {
-
-  private final Executor executor;
-  private final HeaderProvider headerProvider;
-  private final HttpJsonInterceptorProvider interceptorProvider;
-  private final String endpoint;
-  private final HttpTransport httpTransport;
-  private final MtlsProvider mtlsProvider;
-
-  private InstantiatingHttpJsonChannelProvider(
-      Executor executor,
-      HeaderProvider headerProvider,
-      HttpJsonInterceptorProvider interceptorProvider,
-      String endpoint,
-      HttpTransport httpTransport,
-      MtlsProvider mtlsProvider) {
-    this.executor = executor;
-    this.headerProvider = headerProvider;
-    this.interceptorProvider = interceptorProvider;
-    this.endpoint = endpoint;
-    this.httpTransport = httpTransport;
-    this.mtlsProvider = mtlsProvider;
-  }
-
-  /**
-   * @deprecated If executor is not set, this channel provider will create channels with default
-   *     executor defined in {@link ManagedHttpJsonChannel}.
-   */
-  @Deprecated
-  @Override
-  public boolean needsExecutor() {
-    return executor == null;
-  }
-
-  @Deprecated
-  @Override
-  public TransportChannelProvider withExecutor(ScheduledExecutorService executor) {
-    return withExecutor((Executor) executor);
-  }
-
-  @Override
-  public TransportChannelProvider withExecutor(Executor executor) {
-    return toBuilder().setExecutor(executor).build();
-  }
-
-  @Override
-  public boolean needsHeaders() {
-    return headerProvider == null;
-  }
-
-  @Override
-  public TransportChannelProvider withHeaders(Map<String, String> headers) {
-    return toBuilder().setHeaderProvider(FixedHeaderProvider.create(headers)).build();
-  }
-
-  @Override
-  public boolean needsEndpoint() {
-    return endpoint == null;
-  }
-
-  @Override
-  public TransportChannelProvider withEndpoint(String endpoint) {
-    return toBuilder().setEndpoint(endpoint).build();
-  }
-
-  /** @deprecated REST transport channel doesn't support channel pooling */
-  @Deprecated
-  @Override
-  public boolean acceptsPoolSize() {
-    return false;
-  }
-
-  /** @deprecated REST transport channel doesn't support channel pooling */
-  @Deprecated
-  @Override
-  public TransportChannelProvider withPoolSize(int size) {
-    throw new UnsupportedOperationException(
-        "InstantiatingHttpJsonChannelProvider doesn't allow pool size customization");
-  }
-
-  @Override
-  public String getTransportName() {
-    return HttpJsonTransportChannel.getHttpJsonTransportName();
-  }
-
-  @Override
-  public HttpJsonTransportChannel getTransportChannel() throws IOException {
-    if (needsHeaders()) {
-      throw new IllegalStateException("getTransportChannel() called when needsHeaders() is true");
-    } else {
-      try {
-        return createChannel();
-      } catch (GeneralSecurityException e) {
-        throw new IOException(e);
-      }
-    }
-  }
-
-  @Override
-  public boolean needsCredentials() {
-    return false;
-  }
-
-  @Override
-  public TransportChannelProvider withCredentials(Credentials credentials) {
-    throw new UnsupportedOperationException(
-        "InstantiatingHttpJsonChannelProvider doesn't need credentials");
-  }
-
-  HttpTransport createHttpTransport() throws IOException, GeneralSecurityException {
-    if (mtlsProvider.useMtlsClientCertificate()) {
-      KeyStore mtlsKeyStore = mtlsProvider.getKeyStore();
-      if (mtlsKeyStore != null) {
-        return new NetHttpTransport.Builder().trustCertificates(null, mtlsKeyStore, "").build();
-      }
-    }
-    return null;
-  }
-
-  private HttpJsonTransportChannel createChannel() throws IOException, GeneralSecurityException {
-    HttpTransport httpTransportToUse = httpTransport;
-    if (httpTransportToUse == null) {
-      httpTransportToUse = createHttpTransport();
-    }
-
-    ManagedHttpJsonChannel channel =
-        ManagedHttpJsonChannel.newBuilder()
-            .setEndpoint(endpoint)
-            .setExecutor(executor)
-            .setHttpTransport(httpTransportToUse)
-            .build();
-
-    HttpJsonClientInterceptor headerInterceptor =
-        new HttpJsonHeaderInterceptor(headerProvider.getHeaders());
-
-    channel = new ManagedHttpJsonInterceptorChannel(channel, headerInterceptor);
-    if (interceptorProvider != null && interceptorProvider.getInterceptors() != null) {
-      for (HttpJsonClientInterceptor interceptor : interceptorProvider.getInterceptors()) {
-        channel = new ManagedHttpJsonInterceptorChannel(channel, interceptor);
-      }
-    }
-
-    return HttpJsonTransportChannel.newBuilder().setManagedChannel(channel).build();
-  }
-
-  /** The endpoint to be used for the channel. */
-  public String getEndpoint() {
-    return endpoint;
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return true;
-  }
-
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  public static Builder newBuilder() {
-    return new Builder();
-  }
-
-  public static final class Builder {
-
-    private Executor executor;
-    private HeaderProvider headerProvider;
-    private HttpJsonInterceptorProvider interceptorProvider;
-    private String endpoint;
-    private HttpTransport httpTransport;
-    private MtlsProvider mtlsProvider = new MtlsProvider();
-
-    private Builder() {}
-
-    private Builder(InstantiatingHttpJsonChannelProvider provider) {
-      this.executor = provider.executor;
-      this.headerProvider = provider.headerProvider;
-      this.endpoint = provider.endpoint;
-      this.httpTransport = provider.httpTransport;
-      this.mtlsProvider = provider.mtlsProvider;
-      this.interceptorProvider = provider.interceptorProvider;
-    }
-
-    /**
-     * Sets the Executor for this TransportChannelProvider.
-     *
-     * <p>This is optional; if it is not provided, needsExecutor() will return true, meaning that an
-     * Executor must be provided when getChannel is called on the constructed
-     * TransportChannelProvider instance. Note: InstantiatingHttpJsonChannelProvider will
-     * automatically provide its own Executor in this circumstance when it calls getChannel.
-     */
-    public Builder setExecutor(Executor executor) {
-      this.executor = executor;
-      return this;
-    }
-
-    /** @deprecated Please use {@link #setExecutor(Executor)}. */
-    @Deprecated
-    public Builder setExecutorProvider(ExecutorProvider executorProvider) {
-      return setExecutor((Executor) executorProvider.getExecutor());
-    }
-
-    /**
-     * Sets the HeaderProvider for this TransportChannelProvider.
-     *
-     * <p>This is optional; if it is not provided, needsHeaders() will return true, meaning that
-     * headers must be provided when getChannel is called on the constructed
-     * TransportChannelProvider instance.
-     */
-    public Builder setHeaderProvider(HeaderProvider headerProvider) {
-      this.headerProvider = headerProvider;
-      return this;
-    }
-
-    /**
-     * Sets the GrpcInterceptorProvider for this TransportChannelProvider.
-     *
-     * <p>The provider will be called once for each underlying gRPC ManagedChannel that is created.
-     * It is recommended to return a new list of new interceptors on each call so that interceptors
-     * are not shared among channels, but this is not required.
-     */
-    public Builder setInterceptorProvider(HttpJsonInterceptorProvider interceptorProvider) {
-      this.interceptorProvider = interceptorProvider;
-      return this;
-    }
-
-    /** Sets the endpoint used to reach the service, eg "localhost:8080". */
-    public Builder setEndpoint(String endpoint) {
-      this.endpoint = endpoint;
-      return this;
-    }
-
-    /** Sets the HTTP transport to be used. */
-    public Builder setHttpTransport(HttpTransport httpTransport) {
-      this.httpTransport = httpTransport;
-      return this;
-    }
-
-    public String getEndpoint() {
-      return endpoint;
-    }
-
-    @VisibleForTesting
-    Builder setMtlsProvider(MtlsProvider mtlsProvider) {
-      this.mtlsProvider = mtlsProvider;
-      return this;
-    }
-
-    public InstantiatingHttpJsonChannelProvider build() {
-      return new InstantiatingHttpJsonChannelProvider(
-          executor, headerProvider, interceptorProvider, endpoint, httpTransport, mtlsProvider);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonChannel.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonChannel.java
deleted file mode 100644
index 6fb4200d3..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonChannel.java
+++ /dev/null
@@ -1,147 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.HttpTransport;
-import com.google.api.client.http.javanet.NetHttpTransport;
-import com.google.api.core.BetaApi;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.common.base.Preconditions;
-import java.io.IOException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
-
-/** Implementation of HttpJsonChannel which can issue http-json calls. */
-@BetaApi
-public class ManagedHttpJsonChannel implements HttpJsonChannel, BackgroundResource {
-
-  private static final ExecutorService DEFAULT_EXECUTOR =
-      InstantiatingExecutorProvider.newBuilder().build().getExecutor();
-
-  private final Executor executor;
-  private final String endpoint;
-  private final HttpTransport httpTransport;
-
-  private boolean isTransportShutdown;
-
-  protected ManagedHttpJsonChannel() {
-    this(null, null, null);
-  }
-
-  private ManagedHttpJsonChannel(
-      Executor executor, String endpoint, @Nullable HttpTransport httpTransport) {
-    this.executor = executor;
-    this.endpoint = endpoint;
-    this.httpTransport = httpTransport == null ? new NetHttpTransport() : httpTransport;
-  }
-
-  @Override
-  public <RequestT, ResponseT> HttpJsonClientCall<RequestT, ResponseT> newCall(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, HttpJsonCallOptions callOptions) {
-
-    return new HttpJsonClientCallImpl<>(
-        methodDescriptor, endpoint, callOptions, httpTransport, executor);
-  }
-
-  @Override
-  public synchronized void shutdown() {
-    if (isTransportShutdown) {
-      return;
-    }
-    try {
-      httpTransport.shutdown();
-      isTransportShutdown = true;
-    } catch (IOException e) {
-      e.printStackTrace();
-    }
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return isTransportShutdown;
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return isTransportShutdown;
-  }
-
-  @Override
-  public void shutdownNow() {
-    shutdown();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    // TODO
-    return false;
-  }
-
-  @Override
-  public void close() {}
-
-  public static Builder newBuilder() {
-    return new Builder().setExecutor(DEFAULT_EXECUTOR);
-  }
-
-  public static class Builder {
-
-    private Executor executor;
-    private String endpoint;
-    private HttpTransport httpTransport;
-
-    private Builder() {}
-
-    public Builder setExecutor(Executor executor) {
-      this.executor = executor == null ? DEFAULT_EXECUTOR : executor;
-      return this;
-    }
-
-    public Builder setEndpoint(String endpoint) {
-      this.endpoint = endpoint;
-      return this;
-    }
-
-    public Builder setHttpTransport(HttpTransport httpTransport) {
-      this.httpTransport = httpTransport;
-      return this;
-    }
-
-    public ManagedHttpJsonChannel build() {
-      Preconditions.checkNotNull(endpoint);
-
-      return new ManagedHttpJsonChannel(
-          executor, endpoint, httpTransport == null ? new NetHttpTransport() : httpTransport);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonInterceptorChannel.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonInterceptorChannel.java
deleted file mode 100644
index 05321e2fd..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ManagedHttpJsonInterceptorChannel.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import java.util.concurrent.TimeUnit;
-
-@BetaApi
-class ManagedHttpJsonInterceptorChannel extends ManagedHttpJsonChannel {
-
-  private final ManagedHttpJsonChannel channel;
-  private final HttpJsonClientInterceptor interceptor;
-
-  ManagedHttpJsonInterceptorChannel(
-      ManagedHttpJsonChannel channel, HttpJsonClientInterceptor interceptor) {
-    super();
-    this.channel = channel;
-    this.interceptor = interceptor;
-  }
-
-  @Override
-  public <RequestT, ResponseT> HttpJsonClientCall<RequestT, ResponseT> newCall(
-      ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, HttpJsonCallOptions callOptions) {
-    return interceptor.interceptCall(methodDescriptor, callOptions, channel);
-  }
-
-  @Override
-  public synchronized void shutdown() {
-    channel.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return channel.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return channel.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    channel.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return channel.awaitTermination(duration, unit);
-  }
-
-  @Override
-  public void close() {
-    channel.close();
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/OperationSnapshotFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/OperationSnapshotFactory.java
deleted file mode 100644
index 21a746c51..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/OperationSnapshotFactory.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.gax.longrunning.OperationSnapshot;
-
-/**
- * A factory which creates an {@link OperationSnapshot} from an initial request message (the one
- * which started a long running operation) and an operation response (which may be either initial
- * request response or the polling request response).
- *
- * <p>Public for technical reasons. For internal use only.
- *
- * @param <RequestT> initial request message type
- * @param <OperationT> initial or polling response type
- */
-public interface OperationSnapshotFactory<RequestT, OperationT> {
-  OperationSnapshot create(RequestT request, OperationT response);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/PollingRequestFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/PollingRequestFactory.java
deleted file mode 100644
index f5a6e9c8d..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/PollingRequestFactory.java
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-/**
- * A factory which creates a subsequent polling request from a compund operation id.
- *
- * @param <RequestT> polling request type
- */
-public interface PollingRequestFactory<RequestT> {
-  /**
-   * Creates a polling request message from a {@code compoundOperationId}.
-   *
-   * @param compoundOperationId the compound operation ID, consisting of an operation name and
-   *     potentially any other relevant information delimited by a ':' * character
-   */
-  RequestT create(String compoundOperationId);
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIterator.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIterator.java
deleted file mode 100644
index 84167de5e..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIterator.java
+++ /dev/null
@@ -1,134 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonToken;
-import com.google.gson.stream.JsonWriter;
-import java.io.Closeable;
-import java.io.IOException;
-import java.io.PipedReader;
-import java.io.PipedWriter;
-import java.io.Reader;
-import java.util.Iterator;
-
-/** This class is not thread-safe and is expected to be used under external synchronization. */
-class ProtoMessageJsonStreamIterator implements Closeable, Iterator<Reader> {
-  private volatile boolean arrayStarted;
-  private final JsonReader jsonReader;
-  private final PipedReader reader;
-  private final PipedWriter writer;
-
-  ProtoMessageJsonStreamIterator(Reader rawReader) throws IOException {
-    this.arrayStarted = false;
-    this.jsonReader = new JsonReader(rawReader);
-    this.reader = new PipedReader(0x40000); // 256K
-    this.writer = new PipedWriter();
-    writer.connect(reader);
-  }
-
-  @Override
-  public void close() throws IOException {
-    reader.close();
-    writer.close();
-    jsonReader.close();
-  }
-
-  public boolean hasNext() {
-    try {
-      if (!arrayStarted) {
-        jsonReader.beginArray();
-        arrayStarted = true;
-      }
-      return jsonReader.hasNext();
-    } catch (IOException e) {
-      throw new RestSerializationException(e);
-    }
-  }
-
-  @Override
-  public Reader next() {
-    try {
-      int nestedObjectCount = 0;
-      JsonWriter jsonWriter = new JsonWriter(writer);
-      do {
-        JsonToken token = jsonReader.peek();
-        switch (token) {
-          case BEGIN_ARRAY:
-            jsonReader.beginArray();
-            jsonWriter.beginArray();
-            break;
-          case END_ARRAY:
-            jsonReader.endArray();
-            jsonWriter.endArray();
-            break;
-          case BEGIN_OBJECT:
-            nestedObjectCount++;
-            jsonReader.beginObject();
-            jsonWriter.beginObject();
-            break;
-          case END_OBJECT:
-            jsonReader.endObject();
-            jsonWriter.endObject();
-            nestedObjectCount--;
-            break;
-          case NAME:
-            String name = jsonReader.nextName();
-            jsonWriter.name(name);
-            break;
-          case STRING:
-            String s = jsonReader.nextString();
-            jsonWriter.value(s);
-            break;
-          case NUMBER:
-            String n = jsonReader.nextString();
-            jsonWriter.value(n);
-            break;
-          case BOOLEAN:
-            boolean b = jsonReader.nextBoolean();
-            jsonWriter.value(b);
-            break;
-          case NULL:
-            jsonReader.nextNull();
-            jsonWriter.nullValue();
-            break;
-          case END_DOCUMENT:
-            nestedObjectCount--;
-        }
-      } while (nestedObjectCount > 0);
-
-      jsonWriter.flush();
-
-      return reader;
-    } catch (IOException e) {
-      throw new RestSerializationException(e);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatter.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatter.java
deleted file mode 100644
index f04a16edb..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatter.java
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.pathtemplate.PathTemplate;
-import com.google.protobuf.Message;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-
-/** Creates parts of a HTTP request from a protobuf message. */
-public class ProtoMessageRequestFormatter<RequestT extends Message>
-    implements HttpRequestFormatter<RequestT> {
-
-  private final FieldsExtractor<RequestT, String> requestBodyExtractor;
-  // Using of triple nested generics (which is not pretty) is predetermined by the
-  // Map<String, List<String>> returned value type of the getQueryParamNames interface method
-  // implemented by this class.
-  private final FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor;
-  private final String rawPath;
-  private final PathTemplate pathTemplate;
-  private final FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor;
-  private final List<String> additionalRawPaths;
-  private final List<PathTemplate> additionalPathTemplates;
-
-  private ProtoMessageRequestFormatter(
-      FieldsExtractor<RequestT, String> requestBodyExtractor,
-      FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor,
-      String rawPath,
-      PathTemplate pathTemplate,
-      FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor,
-      List<String> additionalRawPaths,
-      List<PathTemplate> additionalPathTemplates) {
-    this.requestBodyExtractor = requestBodyExtractor;
-    this.queryParamsExtractor = queryParamsExtractor;
-    this.rawPath = rawPath;
-    this.pathTemplate = pathTemplate;
-    this.pathVarsExtractor = pathVarsExtractor;
-    this.additionalRawPaths = additionalRawPaths;
-    this.additionalPathTemplates = additionalPathTemplates;
-  }
-
-  public static <RequestT extends Message>
-      ProtoMessageRequestFormatter.Builder<RequestT> newBuilder() {
-    return new Builder<RequestT>().setAdditionalPaths();
-  }
-
-  public Builder<RequestT> toBuilder() {
-    return new Builder<RequestT>()
-        .setPath(rawPath, pathVarsExtractor)
-        .setAdditionalPaths(additionalRawPaths.toArray(new String[] {}))
-        .setQueryParamsExtractor(queryParamsExtractor)
-        .setRequestBodyExtractor(requestBodyExtractor);
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public Map<String, List<String>> getQueryParamNames(RequestT apiMessage) {
-    return queryParamsExtractor.extract(apiMessage);
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public String getRequestBody(RequestT apiMessage) {
-    return requestBodyExtractor.extract(apiMessage);
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public String getPath(RequestT apiMessage) {
-    return pathTemplate.instantiate(pathVarsExtractor.extract(apiMessage));
-  }
-
-  @BetaApi
-  @Override
-  public List<PathTemplate> getAdditionalPathTemplates() {
-    return additionalPathTemplates;
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public PathTemplate getPathTemplate() {
-    return pathTemplate;
-  }
-
-  // This has class has compound setter methods (multiple arguments in setters), that is why not
-  // using @AutoValue.
-  public static class Builder<RequestT extends Message> {
-    private FieldsExtractor<RequestT, String> requestBodyExtractor;
-    private FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor;
-    private String rawPath;
-    private FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor;
-    private List<String> rawAdditionalPaths;
-
-    public Builder<RequestT> setRequestBodyExtractor(
-        FieldsExtractor<RequestT, String> requestBodyExtractor) {
-      this.requestBodyExtractor = requestBodyExtractor;
-      return this;
-    }
-
-    public Builder<RequestT> setQueryParamsExtractor(
-        FieldsExtractor<RequestT, Map<String, List<String>>> queryParamsExtractor) {
-      this.queryParamsExtractor = queryParamsExtractor;
-      return this;
-    }
-
-    public Builder<RequestT> setPath(
-        String rawPath, FieldsExtractor<RequestT, Map<String, String>> pathVarsExtractor) {
-      this.rawPath = rawPath;
-      this.pathVarsExtractor = pathVarsExtractor;
-      return this;
-    }
-
-    @BetaApi
-    public Builder<RequestT> setAdditionalPaths(String... rawAdditionalPaths) {
-      this.rawAdditionalPaths = Arrays.asList(rawAdditionalPaths);
-      return this;
-    }
-
-    @InternalApi
-    public Builder<RequestT> updateRawPath(String target, String replacement) {
-      this.rawPath = this.rawPath.replace(target, replacement);
-      return this;
-    }
-
-    public ProtoMessageRequestFormatter<RequestT> build() {
-      return new ProtoMessageRequestFormatter<>(
-          requestBodyExtractor,
-          queryParamsExtractor,
-          rawPath,
-          PathTemplate.create(rawPath),
-          pathVarsExtractor,
-          rawAdditionalPaths,
-          rawAdditionalPaths.stream().map(PathTemplate::create).collect(Collectors.toList()));
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageResponseParser.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageResponseParser.java
deleted file mode 100644
index 815d19c7a..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoMessageResponseParser.java
+++ /dev/null
@@ -1,104 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.protobuf.Message;
-import com.google.protobuf.TypeRegistry;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.Reader;
-import java.nio.charset.StandardCharsets;
-
-/** The implementation of {@link HttpResponseParser} which works with protobuf messages. */
-public class ProtoMessageResponseParser<ResponseT extends Message>
-    implements HttpResponseParser<ResponseT> {
-
-  private final ResponseT defaultInstance;
-  private final TypeRegistry defaultRegistry;
-
-  private ProtoMessageResponseParser(ResponseT defaultInstance, TypeRegistry defaultRegistry) {
-    this.defaultInstance = defaultInstance;
-    this.defaultRegistry = defaultRegistry;
-  }
-
-  public static <ResponseT extends Message>
-      ProtoMessageResponseParser.Builder<ResponseT> newBuilder() {
-    return new ProtoMessageResponseParser.Builder<ResponseT>()
-        .setDefaultTypeRegistry(TypeRegistry.getEmptyTypeRegistry());
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public ResponseT parse(InputStream httpContent) {
-    return parse(httpContent, defaultRegistry);
-  }
-
-  @Override
-  public ResponseT parse(InputStream httpContent, TypeRegistry registry) {
-    try (Reader json = new InputStreamReader(httpContent, StandardCharsets.UTF_8)) {
-      return parse(json, registry);
-    } catch (IOException e) {
-      throw new RestSerializationException("Failed to parse response message", e);
-    }
-  }
-
-  @Override
-  public ResponseT parse(Reader httpContent, TypeRegistry registry) {
-    return ProtoRestSerializer.<ResponseT>create(registry)
-        .fromJson(httpContent, defaultInstance.newBuilderForType());
-  }
-
-  /* {@inheritDoc} */
-  @Override
-  public String serialize(ResponseT response) {
-    return ProtoRestSerializer.create(defaultRegistry).toJson(response, false);
-  }
-
-  // Convert to @AutoValue if this class gets more complicated
-  public static class Builder<ResponseT extends Message> {
-    private ResponseT defaultInstance;
-    private TypeRegistry defaultRegistry;
-
-    public Builder<ResponseT> setDefaultInstance(ResponseT defaultInstance) {
-      this.defaultInstance = defaultInstance;
-      return this;
-    }
-
-    public Builder<ResponseT> setDefaultTypeRegistry(TypeRegistry defaultRegistry) {
-      this.defaultRegistry = defaultRegistry;
-      return this;
-    }
-
-    public ProtoMessageResponseParser<ResponseT> build() {
-      return new ProtoMessageResponseParser<>(defaultInstance, defaultRegistry);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoOperationTransformers.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoOperationTransformers.java
deleted file mode 100644
index a5a3e436c..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoOperationTransformers.java
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.protobuf.Any;
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.Message;
-
-/** Public for technical reasons; intended for use by generated code. */
-public class ProtoOperationTransformers {
-  private ProtoOperationTransformers() {}
-
-  public static class ResponseTransformer<ResponseT extends Message>
-      implements ApiFunction<OperationSnapshot, ResponseT> {
-    private final AnyTransformer<ResponseT> transformer;
-
-    private ResponseTransformer(Class<ResponseT> packedClass) {
-      this.transformer = new AnyTransformer<>(packedClass);
-    }
-
-    @Override
-    public ResponseT apply(OperationSnapshot operationSnapshot) {
-      if (!operationSnapshot.getErrorCode().getCode().equals(Code.OK)) {
-        throw ApiExceptionFactory.createException(
-            "Operation with name \""
-                + operationSnapshot.getName()
-                + "\" failed with status = "
-                + operationSnapshot.getErrorCode()
-                + " and message = "
-                + operationSnapshot.getErrorMessage(),
-            null,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-
-      if (!(operationSnapshot.getResponse() instanceof Any)) {
-        return (ResponseT) operationSnapshot.getResponse();
-      }
-
-      try {
-        return transformer.apply((Any) operationSnapshot.getResponse());
-      } catch (RuntimeException e) {
-        throw ApiExceptionFactory.createException(
-            "Operation with name \""
-                + operationSnapshot.getName()
-                + "\" succeeded, but encountered a problem unpacking it.",
-            e,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-    }
-
-    public static <ResponseT extends Message> ResponseTransformer<ResponseT> create(
-        Class<ResponseT> packedClass) {
-      return new ResponseTransformer<>(packedClass);
-    }
-  }
-
-  public static class MetadataTransformer<MetadataT extends Message>
-      implements ApiFunction<OperationSnapshot, MetadataT> {
-    private final AnyTransformer<MetadataT> transformer;
-
-    private MetadataTransformer(Class<MetadataT> packedClass) {
-      this.transformer = new AnyTransformer<>(packedClass);
-    }
-
-    @Override
-    public MetadataT apply(OperationSnapshot operationSnapshot) {
-      if (!(operationSnapshot.getMetadata() instanceof Any)) {
-        return (MetadataT) operationSnapshot.getMetadata();
-      }
-      try {
-        return transformer.apply((Any) operationSnapshot.getMetadata());
-      } catch (RuntimeException e) {
-        throw ApiExceptionFactory.createException(
-            "Polling operation with name \""
-                + operationSnapshot.getName()
-                + "\" succeeded, but encountered a problem unpacking it.",
-            e,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-    }
-
-    public static <ResponseT extends Message> MetadataTransformer<ResponseT> create(
-        Class<ResponseT> packedClass) {
-      return new MetadataTransformer<>(packedClass);
-    }
-  }
-
-  static class AnyTransformer<PackedT extends Message> implements ApiFunction<Any, PackedT> {
-    private final Class<PackedT> packedClass;
-
-    public AnyTransformer(Class<PackedT> packedClass) {
-      this.packedClass = packedClass;
-    }
-
-    @Override
-    public PackedT apply(Any input) {
-      try {
-        return input == null || packedClass == null ? null : input.unpack(packedClass);
-      } catch (InvalidProtocolBufferException | ClassCastException e) {
-        throw new IllegalStateException(
-            "Failed to unpack object from 'any' field. Expected "
-                + packedClass.getName()
-                + ", found "
-                + input.getTypeUrl());
-      }
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoRestSerializer.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoRestSerializer.java
deleted file mode 100644
index 0c5158f76..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ProtoRestSerializer.java
+++ /dev/null
@@ -1,192 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-import com.google.common.collect.ImmutableList;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonParser;
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.Message;
-import com.google.protobuf.TypeRegistry;
-import com.google.protobuf.util.JsonFormat;
-import com.google.protobuf.util.JsonFormat.Printer;
-import java.io.IOException;
-import java.io.Reader;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-
-/**
- * This class serializes/deserializes protobuf {@link Message} for REST interactions. It serializes
- * requests protobuf messages into REST messages, splitting the message into the JSON request body,
- * URL path parameters, and query parameters. It deserializes JSON responses into response protobuf
- * message.
- */
-@BetaApi
-public class ProtoRestSerializer<RequestT extends Message> {
-
-  private final TypeRegistry registry;
-
-  private ProtoRestSerializer(TypeRegistry registry) {
-    this.registry = registry;
-  }
-
-  /** Creates a new instance of ProtoRestSerializer. */
-  public static <RequestT extends Message> ProtoRestSerializer<RequestT> create() {
-    return create(TypeRegistry.getEmptyTypeRegistry());
-  }
-
-  /** Creates a new instance of ProtoRestSerializer. */
-  static <RequestT extends Message> ProtoRestSerializer<RequestT> create(TypeRegistry registry) {
-    return new ProtoRestSerializer<>(registry);
-  }
-
-  /**
-   * Serializes the data from {@code message} to a JSON string. The implementation relies on
-   * protobuf native JSON formatter.
-   *
-   * @param message a message to serialize
-   * @param numericEnum a boolean flag that determine if enum values should be serialized to number
-   *     or not
-   * @throws InvalidProtocolBufferException if failed to serialize the protobuf message to JSON
-   *     format
-   */
-  String toJson(Message message, boolean numericEnum) {
-    try {
-      Printer printer = JsonFormat.printer().usingTypeRegistry(registry);
-      if (numericEnum) {
-        return printer.printingEnumsAsInts().print(message);
-      } else {
-        return printer.print(message);
-      }
-    } catch (InvalidProtocolBufferException e) {
-      throw new RestSerializationException("Failed to serialize message to JSON", e);
-    }
-  }
-
-  /**
-   * Deserializes a {@code message} from an input stream to a protobuf message.
-   *
-   * @param json the input reader with a JSON-encoded message in it
-   * @param builder an empty builder for the specific {@code RequestT} message to serialize
-   * @throws RestSerializationException if failed to deserialize a protobuf message from the JSON
-   *     stream
-   */
-  @SuppressWarnings("unchecked")
-  RequestT fromJson(Reader json, Message.Builder builder) {
-    try {
-      JsonFormat.parser().usingTypeRegistry(registry).ignoringUnknownFields().merge(json, builder);
-      return (RequestT) builder.build();
-    } catch (IOException e) {
-      throw new RestSerializationException("Failed to parse response message", e);
-    }
-  }
-
-  /**
-   * Puts a message field in {@code fields} map which will be used to populate URL path of a
-   * request.
-   *
-   * @param fields a map with serialized fields
-   * @param fieldName a field name
-   * @param fieldValue a field value
-   */
-  public void putPathParam(Map<String, String> fields, String fieldName, Object fieldValue) {
-    fields.put(fieldName, String.valueOf(fieldValue));
-  }
-
-  private void putDecomposedMessageQueryParam(
-      Map<String, List<String>> fields, String fieldName, JsonElement parsed) {
-    if (parsed.isJsonPrimitive() || parsed.isJsonNull()) {
-      putQueryParam(fields, fieldName, parsed.getAsString());
-    } else if (parsed.isJsonArray()) {
-      for (JsonElement element : parsed.getAsJsonArray()) {
-        putDecomposedMessageQueryParam(fields, fieldName, element);
-      }
-    } else {
-      // it is a json object
-      for (String key : parsed.getAsJsonObject().keySet()) {
-        putDecomposedMessageQueryParam(
-            fields, String.format("%s.%s", fieldName, key), parsed.getAsJsonObject().get(key));
-      }
-    }
-  }
-
-  /**
-   * Puts a message field in {@code fields} map which will be used to populate query parameters of a
-   * request.
-   *
-   * @param fields a map with serialized fields
-   * @param fieldName a field name
-   * @param fieldValue a field value
-   */
-  public void putQueryParam(Map<String, List<String>> fields, String fieldName, Object fieldValue) {
-    List<String> currentParamValueList = new ArrayList<>();
-    List<Object> toProcess =
-        fieldValue instanceof List<?> ? (List<Object>) fieldValue : ImmutableList.of(fieldValue);
-    for (Object fieldValueItem : toProcess) {
-      if (fieldValueItem instanceof Message) {
-        String json = toJson(((Message) fieldValueItem), true);
-        JsonElement parsed = JsonParser.parseString(json);
-        putDecomposedMessageQueryParam(fields, fieldName, parsed);
-      } else {
-        currentParamValueList.add(String.valueOf(fieldValueItem));
-      }
-    }
-    if (currentParamValueList.isEmpty()) {
-      // We try to avoid putting non-leaf level fields to the query params
-      return;
-    }
-    List<String> accumulativeParamValueList = fields.getOrDefault(fieldName, new ArrayList<>());
-    accumulativeParamValueList.addAll(currentParamValueList);
-    fields.put(fieldName, accumulativeParamValueList);
-  }
-
-  /**
-   * Serializes a message to a request body in a form of JSON-encoded string.
-   *
-   * @param fieldName a name of a request message field this message belongs to
-   * @param fieldValue a field value to serialize
-   */
-  public String toBody(String fieldName, RequestT fieldValue) {
-    return toJson(fieldValue, false);
-  }
-
-  /**
-   * Serializes a message to a request body in a form of JSON-encoded string.
-   *
-   * @param fieldName a name of a request message field this message belongs to
-   * @param fieldValue a field value to serialize
-   * @param numericEnum a boolean flag that determine if enum values should be serialized to number
-   */
-  public String toBody(String fieldName, RequestT fieldValue, boolean numericEnum) {
-    return toJson(fieldValue, numericEnum);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/RestSerializationException.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/RestSerializationException.java
deleted file mode 100644
index 7f5252595..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/RestSerializationException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.BetaApi;
-
-/**
- * An exception thrown when a protobuf message cannot be serialized/deserialized for REST
- * interactions.
- */
-@BetaApi
-public class RestSerializationException extends RuntimeException {
-
-  private static final long serialVersionUID = -6485633460933364916L;
-
-  public RestSerializationException(Throwable cause) {
-    super(cause);
-  }
-
-  public RestSerializationException(String message, Throwable cause) {
-    super(message, cause);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsClient.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsClient.java
deleted file mode 100644
index fe5093c19..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsClient.java
+++ /dev/null
@@ -1,655 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.httpjson.longrunning.stub.OperationsStub;
-import com.google.api.gax.httpjson.longrunning.stub.OperationsStubSettings;
-import com.google.api.gax.paging.AbstractFixedSizeCollection;
-import com.google.api.gax.paging.AbstractPage;
-import com.google.api.gax.paging.AbstractPagedListResponse;
-import com.google.api.gax.rpc.PageContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.util.concurrent.MoreExecutors;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * Service Description: Manages long-running operations with an API service.
- *
- * <p>When an API method normally takes long time to complete, it can be designed to return
- * [Operation][google.longrunning.Operation] to the client, and the client can use this interface to
- * receive the real response asynchronously by polling the operation resource, or pass the operation
- * resource to another API (such as Google Cloud Pub/Sub API) to receive the response. Any API
- * service that returns long-running operations should implement the `Operations` interface so
- * developers can have a consistent client experience.
- *
- * <p>This class provides the ability to make remote calls to the backing service through method
- * calls that map to API methods. Sample code to get started:
- *
- * <pre>{@code
- * try (OperationsClient operationsClient = OperationsClient.create()) {
- *   String name = "name3373707";
- *   Operation response = operationsClient.getOperation(name);
- * }
- * }</pre>
- *
- * <p>Note: close() needs to be called on the OperationsClient object to clean up resources such as
- * threads. In the example above, try-with-resources is used, which automatically calls close().
- *
- * <p>The surface of this class includes several types of Java methods for each of the API's
- * methods:
- *
- * <ol>
- *   <li>A "flattened" method. With this type of method, the fields of the request type have been
- *       converted into function parameters. It may be the case that not all fields are available as
- *       parameters, and not every API method will have a flattened method entry point.
- *   <li>A "request object" method. This type of method only takes one parameter, a request object,
- *       which must be constructed before the call. Not every API method will have a request object
- *       method.
- *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
- *       callable object, which can be used to initiate calls to the service.
- * </ol>
- *
- * <p>See the individual methods for example code.
- *
- * <p>Many parameters require resource names to be formatted in a particular way. To assist with
- * these names, this class includes a format method for each type of name, and additionally a parse
- * method to extract the individual identifiers contained within names that are returned.
- *
- * <p>This class can be customized by passing in a custom instance of OperationsSettings to
- * create(). For example:
- *
- * <p>To customize credentials:
- *
- * <pre>{@code
- * OperationsSettings operationsSettings =
- *     OperationsSettings.newBuilder()
- *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
- *         .build();
- * OperationsClient operationsClient = OperationsClient.create(operationsSettings);
- * }</pre>
- *
- * <p>To customize the endpoint:
- *
- * <pre>{@code
- * OperationsSettings operationsSettings =
- *     OperationsSettings.newBuilder().setEndpoint(myEndpoint).build();
- * OperationsClient operationsClient = OperationsClient.create(operationsSettings);
- * }</pre>
- *
- * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
- */
-@BetaApi
-public class OperationsClient implements BackgroundResource {
-  private final OperationsSettings settings;
-  private final OperationsStub stub;
-
-  /** Constructs an instance of OperationsClient with default settings. */
-  public static final OperationsClient create() throws IOException {
-    return create(OperationsSettings.newBuilder().build());
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given settings. The channels are created
-   * based on the settings passed in, or defaults for any settings that are not set.
-   */
-  public static final OperationsClient create(OperationsSettings settings) throws IOException {
-    return new OperationsClient(settings);
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given stub for making calls. This is for
-   * advanced usage - prefer using create(OperationsSettings).
-   */
-  public static final OperationsClient create(OperationsStub stub) {
-    return new OperationsClient(stub);
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given stub for making calls. This is for
-   * advanced usage - prefer using create(OperationsSettings).
-   */
-  public static final OperationsClient create(BackgroundResource stub) {
-    return new OperationsClient((OperationsStub) stub);
-  }
-
-  /**
-   * Constructs an instance of OperationsClient, using the given settings. This is protected so that
-   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
-   */
-  protected OperationsClient(OperationsSettings settings) throws IOException {
-    this.settings = settings;
-    this.stub = ((OperationsStubSettings) settings.getStubSettings()).createStub();
-  }
-
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
-  protected OperationsClient(OperationsStub stub) {
-    this.settings = null;
-    this.stub = stub;
-  }
-
-  public final OperationsSettings getSettings() {
-    return settings;
-  }
-
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
-  public OperationsStub getStub() {
-    return stub;
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`. To override the binding, API services
-   * can add a binding such as `"/v1/{name=users/&#42;}/operations"` to their service configuration.
-   * For backwards compatibility, the default name includes the operations collection id, however
-   * overriding users must ensure the name binding is the parent resource, without the operations
-   * collection id.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "name3373707";
-   *   String filter = "filter-1274492040";
-   *   for (Operation element : operationsClient.listOperations(name, filter).iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * }</pre>
-   *
-   * @param name The name of the operation's parent resource.
-   * @param filter The standard list filter.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final ListOperationsPagedResponse listOperations(String name, String filter) {
-    ListOperationsRequest request =
-        ListOperationsRequest.newBuilder().setName(name).setFilter(filter).build();
-    return listOperations(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`. To override the binding, API services
-   * can add a binding such as `"/v1/{name=users/&#42;}/operations"` to their service configuration.
-   * For backwards compatibility, the default name includes the operations collection id, however
-   * overriding users must ensure the name binding is the parent resource, without the operations
-   * collection id.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   ListOperationsRequest request =
-   *       ListOperationsRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setFilter("filter-1274492040")
-   *           .setPageSize(883849137)
-   *           .setPageToken("pageToken873572522")
-   *           .build();
-   *   for (Operation element : operationsClient.listOperations(request).iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * }</pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final ListOperationsPagedResponse listOperations(ListOperationsRequest request) {
-    return listOperationsPagedCallable().call(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`. To override the binding, API services
-   * can add a binding such as `"/v1/{name=users/&#42;}/operations"` to their service configuration.
-   * For backwards compatibility, the default name includes the operations collection id, however
-   * overriding users must ensure the name binding is the parent resource, without the operations
-   * collection id.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   ListOperationsRequest request =
-   *       ListOperationsRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setFilter("filter-1274492040")
-   *           .setPageSize(883849137)
-   *           .setPageToken("pageToken873572522")
-   *           .build();
-   *   ApiFuture<Operation> future =
-   *       operationsClient.listOperationsPagedCallable().futureCall(request);
-   *   // Do something.
-   *   for (Operation element : future.get().iterateAll()) {
-   *     // doThingsWith(element);
-   *   }
-   * }
-   * }</pre>
-   */
-  public final UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    return stub.listOperationsPagedCallable();
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Lists operations that match the specified filter in the request. If the server doesn't support
-   * this method, it returns `UNIMPLEMENTED`.
-   *
-   * <p>NOTE: the `name` binding allows API services to override the binding to use different
-   * resource name schemes, such as `users/&#42;/operations`. To override the binding, API services
-   * can add a binding such as `"/v1/{name=users/&#42;}/operations"` to their service configuration.
-   * For backwards compatibility, the default name includes the operations collection id, however
-   * overriding users must ensure the name binding is the parent resource, without the operations
-   * collection id.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   ListOperationsRequest request =
-   *       ListOperationsRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setFilter("filter-1274492040")
-   *           .setPageSize(883849137)
-   *           .setPageToken("pageToken873572522")
-   *           .build();
-   *   while (true) {
-   *     ListOperationsResponse response = operationsClient.listOperationsCallable().call(request);
-   *     for (Operation element : response.getResponsesList()) {
-   *       // doThingsWith(element);
-   *     }
-   *     String nextPageToken = response.getNextPageToken();
-   *     if (!Strings.isNullOrEmpty(nextPageToken)) {
-   *       request = request.toBuilder().setPageToken(nextPageToken).build();
-   *     } else {
-   *       break;
-   *     }
-   *   }
-   * }
-   * }</pre>
-   */
-  public final UnaryCallable<ListOperationsRequest, ListOperationsResponse>
-      listOperationsCallable() {
-    return stub.listOperationsCallable();
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "name3373707";
-   *   Operation response = operationsClient.getOperation(name);
-   * }
-   * }</pre>
-   *
-   * @param name The name of the operation resource.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final Operation getOperation(String name) {
-    GetOperationRequest request = GetOperationRequest.newBuilder().setName(name).build();
-    return getOperation(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   GetOperationRequest request = GetOperationRequest.newBuilder().setName("name3373707").build();
-   *   Operation response = operationsClient.getOperation(request);
-   * }
-   * }</pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final Operation getOperation(GetOperationRequest request) {
-    return getOperationCallable().call(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Gets the latest state of a long-running operation. Clients can use this method to poll the
-   * operation result at intervals as recommended by the API service.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   GetOperationRequest request = GetOperationRequest.newBuilder().setName("name3373707").build();
-   *   ApiFuture<Operation> future = operationsClient.getOperationCallable().futureCall(request);
-   *   // Do something.
-   *   Operation response = future.get();
-   * }
-   * }</pre>
-   */
-  public final UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    return stub.getOperationCallable();
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "name3373707";
-   *   operationsClient.deleteOperation(name);
-   * }
-   * }</pre>
-   *
-   * @param name The name of the operation resource to be deleted.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void deleteOperation(String name) {
-    DeleteOperationRequest request = DeleteOperationRequest.newBuilder().setName(name).build();
-    deleteOperation(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   DeleteOperationRequest request =
-   *       DeleteOperationRequest.newBuilder().setName("name3373707").build();
-   *   operationsClient.deleteOperation(request);
-   * }
-   * }</pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void deleteOperation(DeleteOperationRequest request) {
-    deleteOperationCallable().call(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Deletes a long-running operation. This method indicates that the client is no longer interested
-   * in the operation result. It does not cancel the operation. If the server doesn't support this
-   * method, it returns `google.rpc.Code.UNIMPLEMENTED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   DeleteOperationRequest request =
-   *       DeleteOperationRequest.newBuilder().setName("name3373707").build();
-   *   ApiFuture<Empty> future = operationsClient.deleteOperationCallable().futureCall(request);
-   *   // Do something.
-   *   future.get();
-   * }
-   * }</pre>
-   */
-  public final UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    return stub.deleteOperationCallable();
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   String name = "name3373707";
-   *   operationsClient.cancelOperation(name);
-   * }
-   * }</pre>
-   *
-   * @param name The name of the operation resource to be cancelled.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void cancelOperation(String name) {
-    CancelOperationRequest request = CancelOperationRequest.newBuilder().setName(name).build();
-    cancelOperation(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   CancelOperationRequest request =
-   *       CancelOperationRequest.newBuilder().setName("name3373707").build();
-   *   operationsClient.cancelOperation(request);
-   * }
-   * }</pre>
-   *
-   * @param request The request object containing all of the parameters for the API call.
-   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
-   */
-  public final void cancelOperation(CancelOperationRequest request) {
-    cancelOperationCallable().call(request);
-  }
-
-  // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /**
-   * Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
-   * cancel the operation, but success is not guaranteed. If the server doesn't support this method,
-   * it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
-   * [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
-   * whether the cancellation succeeded or whether the operation completed despite cancellation. On
-   * successful cancellation, the operation is not deleted; instead, it becomes an operation with an
-   * [Operation.error][google.longrunning.Operation.error] value with a
-   * [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
-   *
-   * <p>Sample code:
-   *
-   * <pre>{@code
-   * try (OperationsClient operationsClient = OperationsClient.create()) {
-   *   CancelOperationRequest request =
-   *       CancelOperationRequest.newBuilder().setName("name3373707").build();
-   *   ApiFuture<Empty> future = operationsClient.cancelOperationCallable().futureCall(request);
-   *   // Do something.
-   *   future.get();
-   * }
-   * }</pre>
-   */
-  public final UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    return stub.cancelOperationCallable();
-  }
-
-  @Override
-  public final void close() {
-    stub.close();
-  }
-
-  @Override
-  public void shutdown() {
-    stub.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return stub.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return stub.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    stub.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return stub.awaitTermination(duration, unit);
-  }
-
-  public static class ListOperationsPagedResponse
-      extends AbstractPagedListResponse<
-          ListOperationsRequest,
-          ListOperationsResponse,
-          Operation,
-          ListOperationsPage,
-          ListOperationsFixedSizeCollection> {
-
-    public static ApiFuture<ListOperationsPagedResponse> createAsync(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ApiFuture<ListOperationsResponse> futureResponse) {
-      ApiFuture<ListOperationsPage> futurePage =
-          ListOperationsPage.createEmptyPage().createPageAsync(context, futureResponse);
-      return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListOperationsPage, ListOperationsPagedResponse>() {
-            @Override
-            public ListOperationsPagedResponse apply(ListOperationsPage input) {
-              return new ListOperationsPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
-    }
-
-    private ListOperationsPagedResponse(ListOperationsPage page) {
-      super(page, ListOperationsFixedSizeCollection.createEmptyCollection());
-    }
-  }
-
-  public static class ListOperationsPage
-      extends AbstractPage<
-          ListOperationsRequest, ListOperationsResponse, Operation, ListOperationsPage> {
-
-    private ListOperationsPage(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ListOperationsResponse response) {
-      super(context, response);
-    }
-
-    private static ListOperationsPage createEmptyPage() {
-      return new ListOperationsPage(null, null);
-    }
-
-    @Override
-    protected ListOperationsPage createPage(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ListOperationsResponse response) {
-      return new ListOperationsPage(context, response);
-    }
-
-    @Override
-    public ApiFuture<ListOperationsPage> createPageAsync(
-        PageContext<ListOperationsRequest, ListOperationsResponse, Operation> context,
-        ApiFuture<ListOperationsResponse> futureResponse) {
-      return super.createPageAsync(context, futureResponse);
-    }
-  }
-
-  public static class ListOperationsFixedSizeCollection
-      extends AbstractFixedSizeCollection<
-          ListOperationsRequest,
-          ListOperationsResponse,
-          Operation,
-          ListOperationsPage,
-          ListOperationsFixedSizeCollection> {
-
-    private ListOperationsFixedSizeCollection(List<ListOperationsPage> pages, int collectionSize) {
-      super(pages, collectionSize);
-    }
-
-    private static ListOperationsFixedSizeCollection createEmptyCollection() {
-      return new ListOperationsFixedSizeCollection(null, 0);
-    }
-
-    @Override
-    protected ListOperationsFixedSizeCollection createCollection(
-        List<ListOperationsPage> pages, int collectionSize) {
-      return new ListOperationsFixedSizeCollection(pages, collectionSize);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsSettings.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsSettings.java
deleted file mode 100644
index 58aff3d7c..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/OperationsSettings.java
+++ /dev/null
@@ -1,236 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning;
-
-import static com.google.api.gax.httpjson.longrunning.OperationsClient.ListOperationsPagedResponse;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.BetaApi;
-import com.google.api.gax.core.GoogleCredentialsProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
-import com.google.api.gax.httpjson.longrunning.stub.OperationsStubSettings;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientSettings;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import java.util.List;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * Settings class to configure an instance of {@link OperationsClient}.
- *
- * <p>The default instance has everything set to sensible defaults:
- *
- * <ul>
- *   <li>The default service address (longrunning.googleapis.com) and default port (443) are used.
- *   <li>Credentials are acquired automatically through Application Default Credentials.
- *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
- * </ul>
- *
- * <p>The builder of this class is recursive, so contained classes are themselves builders. When
- * build() is called, the tree of builders is called to create the complete settings object.
- *
- * <p>For example, to set the total timeout of getOperation to 30 seconds:
- *
- * <pre>{@code
- * OperationsSettings.Builder operationsSettingsBuilder = OperationsSettings.newBuilder();
- * operationsSettingsBuilder
- *     .getOperationSettings()
- *     .setRetrySettings(
- *         operationsSettingsBuilder
- *             .getOperationSettings()
- *             .getRetrySettings()
- *             .toBuilder()
- *             .setTotalTimeout(Duration.ofSeconds(30))
- *             .build());
- * OperationsSettings operationsSettings = operationsSettingsBuilder.build();
- * }</pre>
- */
-@BetaApi
-public class OperationsSettings extends ClientSettings<OperationsSettings> {
-
-  /** Returns the object with the settings used for calls to listOperations. */
-  public PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings() {
-    return ((OperationsStubSettings) getStubSettings()).listOperationsSettings();
-  }
-
-  /** Returns the object with the settings used for calls to get. */
-  public UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).getOperationSettings();
-  }
-
-  /** Returns the object with the settings used for calls to delete. */
-  public UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).deleteOperationSettings();
-  }
-
-  /** Returns the object with the settings used for calls to cancel. */
-  public UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings() {
-    return ((OperationsStubSettings) getStubSettings()).cancelOperationSettings();
-  }
-
-  public static final OperationsSettings create(OperationsStubSettings stub) throws IOException {
-    return new OperationsSettings.Builder(stub.toBuilder()).build();
-  }
-
-  /** Returns a builder for the default ExecutorProvider for this service. */
-  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
-    return OperationsStubSettings.defaultExecutorProviderBuilder();
-  }
-
-  /** Returns the default service endpoint. */
-  public static String getDefaultEndpoint() {
-    return OperationsStubSettings.getDefaultEndpoint();
-  }
-
-  /** Returns the default service scopes. */
-  public static List<String> getDefaultServiceScopes() {
-    return OperationsStubSettings.getDefaultServiceScopes();
-  }
-
-  /** Returns a builder for the default credentials for this service. */
-  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return OperationsStubSettings.defaultCredentialsProviderBuilder();
-  }
-
-  /** Returns a builder for the default ChannelProvider for this service. */
-  public static InstantiatingHttpJsonChannelProvider.Builder
-      defaultHttpJsonTransportProviderBuilder() {
-    return OperationsStubSettings.defaultHttpJsonTransportProviderBuilder();
-  }
-
-  public static TransportChannelProvider defaultTransportChannelProvider() {
-    return OperationsStubSettings.defaultTransportChannelProvider();
-  }
-
-  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
-    return OperationsStubSettings.defaultApiClientHeaderProviderBuilder();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder() {
-    return Builder.createDefault();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder(ClientContext clientContext) {
-    return new Builder(clientContext);
-  }
-
-  /** Returns a builder containing all the values of this settings class. */
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  protected OperationsSettings(Builder settingsBuilder) throws IOException {
-    super(settingsBuilder);
-  }
-
-  /** Builder for OperationsSettings. */
-  public static class Builder extends ClientSettings.Builder<OperationsSettings, Builder> {
-
-    protected Builder() throws IOException {
-      this(((ClientContext) null));
-    }
-
-    protected Builder(ClientContext clientContext) {
-      super(OperationsStubSettings.newBuilder(clientContext));
-    }
-
-    protected Builder(OperationsSettings settings) {
-      super(settings.getStubSettings().toBuilder());
-    }
-
-    protected Builder(OperationsStubSettings.Builder stubSettings) {
-      super(stubSettings);
-    }
-
-    private static Builder createDefault() {
-      return new Builder(OperationsStubSettings.newBuilder());
-    }
-
-    public OperationsStubSettings.Builder getStubSettingsBuilder() {
-      return ((OperationsStubSettings.Builder) getStubSettings());
-    }
-
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
-    /**
-     * Applies the given settings updater function to all of the unary API methods in this service.
-     *
-     * <p>Note: This method does not support applying settings to streaming methods.
-     */
-    public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
-      super.applyToAllUnaryMethods(
-          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
-      return this;
-    }
-
-    /** Returns the builder for the settings used for calls to listOperations. */
-    public PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings() {
-      return getStubSettingsBuilder().listOperationsSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to get. */
-    public UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings() {
-      return getStubSettingsBuilder().getOperationSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to delete. */
-    public UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings() {
-      return getStubSettingsBuilder().deleteOperationSettings();
-    }
-
-    /** Returns the builder for the settings used for calls to cancel. */
-    public UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings() {
-      return getStubSettingsBuilder().cancelOperationSettings();
-    }
-
-    @Override
-    public OperationsSettings build() throws IOException {
-      return new OperationsSettings(this);
-    }
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsCallableFactory.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsCallableFactory.java
deleted file mode 100644
index 9d8a435d8..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsCallableFactory.java
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning.stub;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.httpjson.HttpJsonCallSettings;
-import com.google.api.gax.httpjson.HttpJsonCallableFactory;
-import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.Operation;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * REST callable factory implementation for the Operations service API.
- *
- * <p>This class is for advanced usage.
- */
-@BetaApi
-public class HttpJsonOperationsCallableFactory
-    implements HttpJsonStubCallableFactory<Operation, BackgroundResource> {
-
-  @Override
-  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    return HttpJsonCallableFactory.createUnaryCallable(
-        httpJsonCallSettings, callSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> callSettings,
-          ClientContext clientContext) {
-    return HttpJsonCallableFactory.createPagedCallable(
-        httpJsonCallSettings, callSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
-      BatchingCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    return HttpJsonCallableFactory.createBatchingCallable(
-        httpJsonCallSettings, callSettings, clientContext);
-  }
-
-  @Override
-  public <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          HttpJsonCallSettings<RequestT, Operation> httpJsonCallSettings,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> callSettings,
-          ClientContext clientContext,
-          BackgroundResource operationsStub) {
-    return null;
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsStub.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsStub.java
deleted file mode 100644
index 5759c4172..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/HttpJsonOperationsStub.java
+++ /dev/null
@@ -1,400 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning.stub;
-
-import com.google.api.client.http.HttpMethods;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.BackgroundResourceAggregation;
-import com.google.api.gax.httpjson.ApiMethodDescriptor;
-import com.google.api.gax.httpjson.HttpJsonCallSettings;
-import com.google.api.gax.httpjson.HttpJsonLongRunningClient;
-import com.google.api.gax.httpjson.HttpJsonOperationSnapshot;
-import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
-import com.google.api.gax.httpjson.ProtoMessageRequestFormatter;
-import com.google.api.gax.httpjson.ProtoMessageResponseParser;
-import com.google.api.gax.httpjson.ProtoRestSerializer;
-import com.google.api.gax.httpjson.longrunning.OperationsClient.ListOperationsPagedResponse;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Empty;
-import com.google.protobuf.Message;
-import com.google.protobuf.TypeRegistry;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.TimeUnit;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * REST stub implementation for the Operations service API.
- *
- * <p>This class is for advanced usage and reflects the underlying API directly.
- */
-public class HttpJsonOperationsStub extends OperationsStub {
-  private static final Pattern CLIENT_PACKAGE_VERSION_PATTERN =
-      Pattern.compile("\\.(?<version>v\\d+[a-zA-Z]*\\d*[a-zA-Z]*\\d*)\\.[\\w.]*stub");
-
-  private static final ApiMethodDescriptor<ListOperationsRequest, ListOperationsResponse>
-      listOperationsMethodDescriptor =
-          ApiMethodDescriptor.<ListOperationsRequest, ListOperationsResponse>newBuilder()
-              .setFullMethodName("google.longrunning.Operations/ListOperations")
-              .setHttpMethod(HttpMethods.GET)
-              .setRequestFormatter(
-                  ProtoMessageRequestFormatter.<ListOperationsRequest>newBuilder()
-                      .setPath(
-                          "/v1/{name=**}/operations",
-                          request -> {
-                            Map<String, String> fields = new HashMap<>();
-                            ProtoRestSerializer<ListOperationsRequest> serializer =
-                                ProtoRestSerializer.create();
-                            serializer.putPathParam(fields, "name", request.getName());
-                            return fields;
-                          })
-                      .setQueryParamsExtractor(
-                          request -> {
-                            Map<String, List<String>> fields = new HashMap<>();
-                            ProtoRestSerializer<ListOperationsRequest> serializer =
-                                ProtoRestSerializer.create();
-                            serializer.putQueryParam(fields, "filter", request.getFilter());
-                            serializer.putQueryParam(fields, "pageSize", request.getPageSize());
-                            serializer.putQueryParam(fields, "pageToken", request.getPageToken());
-                            return fields;
-                          })
-                      .setRequestBodyExtractor(request -> null)
-                      .build())
-              .setResponseParser(
-                  ProtoMessageResponseParser.<ListOperationsResponse>newBuilder()
-                      .setDefaultInstance(ListOperationsResponse.getDefaultInstance())
-                      .build())
-              .build();
-
-  private static final ApiMethodDescriptor<GetOperationRequest, Operation>
-      getOperationMethodDescriptor =
-          ApiMethodDescriptor.<GetOperationRequest, Operation>newBuilder()
-              .setFullMethodName("google.longrunning.Operations/GetOperation")
-              .setHttpMethod(HttpMethods.GET)
-              .setRequestFormatter(
-                  ProtoMessageRequestFormatter.<GetOperationRequest>newBuilder()
-                      .setPath(
-                          "/v1/{name=**/operations/*}",
-                          request -> {
-                            Map<String, String> fields = new HashMap<>();
-                            ProtoRestSerializer<GetOperationRequest> serializer =
-                                ProtoRestSerializer.create();
-                            serializer.putPathParam(fields, "name", request.getName());
-                            return fields;
-                          })
-                      .setQueryParamsExtractor(request -> new HashMap<>())
-                      .setRequestBodyExtractor(request -> null)
-                      .build())
-              .setResponseParser(
-                  ProtoMessageResponseParser.<Operation>newBuilder()
-                      .setDefaultInstance(Operation.getDefaultInstance())
-                      .build())
-              .setOperationSnapshotFactory(
-                  (request, response) -> HttpJsonOperationSnapshot.create(response))
-              .setPollingRequestFactory(
-                  compoundOperationId ->
-                      GetOperationRequest.newBuilder().setName(compoundOperationId).build())
-              .build();
-
-  private static final ApiMethodDescriptor<DeleteOperationRequest, Empty>
-      deleteOperationMethodDescriptor =
-          ApiMethodDescriptor.<DeleteOperationRequest, Empty>newBuilder()
-              .setFullMethodName("google.longrunning.Operations/DeleteOperation")
-              .setHttpMethod(HttpMethods.DELETE)
-              .setRequestFormatter(
-                  ProtoMessageRequestFormatter.<DeleteOperationRequest>newBuilder()
-                      .setPath(
-                          "/v1/{name=**/operations/*}",
-                          request -> {
-                            Map<String, String> fields = new HashMap<>();
-                            ProtoRestSerializer<DeleteOperationRequest> serializer =
-                                ProtoRestSerializer.create();
-                            serializer.putPathParam(fields, "name", request.getName());
-                            return fields;
-                          })
-                      .setQueryParamsExtractor(request -> new HashMap<>())
-                      .setRequestBodyExtractor(request -> null)
-                      .build())
-              .setResponseParser(
-                  ProtoMessageResponseParser.<Empty>newBuilder()
-                      .setDefaultInstance(Empty.getDefaultInstance())
-                      .build())
-              .build();
-
-  private static final ApiMethodDescriptor<CancelOperationRequest, Empty>
-      cancelOperationMethodDescriptor =
-          ApiMethodDescriptor.<CancelOperationRequest, Empty>newBuilder()
-              .setFullMethodName("google.longrunning.Operations/CancelOperation")
-              .setHttpMethod(HttpMethods.POST)
-              .setRequestFormatter(
-                  ProtoMessageRequestFormatter.<CancelOperationRequest>newBuilder()
-                      .setPath(
-                          "/v1/{name=**/operations/*}:cancel",
-                          request -> {
-                            Map<String, String> fields = new HashMap<>();
-                            ProtoRestSerializer<CancelOperationRequest> serializer =
-                                ProtoRestSerializer.create();
-                            serializer.putPathParam(fields, "name", request.getName());
-                            return fields;
-                          })
-                      .setQueryParamsExtractor(request -> new HashMap<>())
-                      .setRequestBodyExtractor(request -> null)
-                      .build())
-              .setResponseParser(
-                  ProtoMessageResponseParser.<Empty>newBuilder()
-                      .setDefaultInstance(Empty.getDefaultInstance())
-                      .build())
-              .build();
-
-  private final UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable;
-  private final UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable;
-  private final UnaryCallable<GetOperationRequest, Operation> getOperationCallable;
-  private final UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable;
-  private final UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable;
-
-  private final LongRunningClient longRunningClient;
-  private final BackgroundResource backgroundResources;
-  private final HttpJsonStubCallableFactory callableFactory;
-
-  public static final HttpJsonOperationsStub create(OperationsStubSettings settings)
-      throws IOException {
-    return new HttpJsonOperationsStub(settings, ClientContext.create(settings));
-  }
-
-  public static final HttpJsonOperationsStub create(ClientContext clientContext)
-      throws IOException {
-    return new HttpJsonOperationsStub(OperationsStubSettings.newBuilder().build(), clientContext);
-  }
-
-  public static final HttpJsonOperationsStub create(
-      ClientContext clientContext, HttpJsonStubCallableFactory callableFactory) throws IOException {
-    return new HttpJsonOperationsStub(
-        OperationsStubSettings.newBuilder().build(),
-        clientContext,
-        callableFactory,
-        TypeRegistry.getEmptyTypeRegistry());
-  }
-
-  public static final HttpJsonOperationsStub create(
-      ClientContext clientContext,
-      HttpJsonStubCallableFactory callableFactory,
-      TypeRegistry typeRegistry)
-      throws IOException {
-    return new HttpJsonOperationsStub(
-        OperationsStubSettings.newBuilder().build(), clientContext, callableFactory, typeRegistry);
-  }
-
-  /**
-   * Constructs an instance of HttpJsonOperationsStub, using the given settings. This is protected
-   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
-   * preferred.
-   */
-  protected HttpJsonOperationsStub(OperationsStubSettings settings, ClientContext clientContext)
-      throws IOException {
-    this(
-        settings,
-        clientContext,
-        new HttpJsonOperationsCallableFactory(),
-        TypeRegistry.getEmptyTypeRegistry());
-  }
-
-  /**
-   * Constructs an instance of HttpJsonOperationsStub, using the given settings. This is protected
-   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
-   * preferred.
-   */
-  protected HttpJsonOperationsStub(
-      OperationsStubSettings settings,
-      ClientContext clientContext,
-      HttpJsonStubCallableFactory callableFactory,
-      TypeRegistry typeRegistry)
-      throws IOException {
-    this.callableFactory = callableFactory;
-
-    Matcher packageMatcher =
-        CLIENT_PACKAGE_VERSION_PATTERN.matcher(callableFactory.getClass().getPackage().getName());
-
-    String apiVersion = packageMatcher.find() ? packageMatcher.group("version") : null;
-
-    HttpJsonCallSettings<ListOperationsRequest, ListOperationsResponse>
-        listOperationsTransportSettings =
-            HttpJsonCallSettings.<ListOperationsRequest, ListOperationsResponse>newBuilder()
-                .setMethodDescriptor(
-                    getApiVersionedMethodDescriptor(listOperationsMethodDescriptor, apiVersion))
-                .setTypeRegistry(typeRegistry)
-                .build();
-    HttpJsonCallSettings<GetOperationRequest, Operation> getOperationTransportSettings =
-        HttpJsonCallSettings.<GetOperationRequest, Operation>newBuilder()
-            .setMethodDescriptor(
-                getApiVersionedMethodDescriptor(getOperationMethodDescriptor, apiVersion))
-            .setTypeRegistry(typeRegistry)
-            .build();
-    HttpJsonCallSettings<DeleteOperationRequest, Empty> deleteOperationTransportSettings =
-        HttpJsonCallSettings.<DeleteOperationRequest, Empty>newBuilder()
-            .setMethodDescriptor(
-                getApiVersionedMethodDescriptor(deleteOperationMethodDescriptor, apiVersion))
-            .setTypeRegistry(typeRegistry)
-            .build();
-    HttpJsonCallSettings<CancelOperationRequest, Empty> cancelOperationTransportSettings =
-        HttpJsonCallSettings.<CancelOperationRequest, Empty>newBuilder()
-            .setMethodDescriptor(
-                getApiVersionedMethodDescriptor(cancelOperationMethodDescriptor, apiVersion))
-            .setTypeRegistry(typeRegistry)
-            .build();
-
-    listOperationsCallable =
-        callableFactory.createUnaryCallable(
-            listOperationsTransportSettings, settings.listOperationsSettings(), clientContext);
-    listOperationsPagedCallable =
-        callableFactory.createPagedCallable(
-            listOperationsTransportSettings, settings.listOperationsSettings(), clientContext);
-    getOperationCallable =
-        callableFactory.createUnaryCallable(
-            getOperationTransportSettings, settings.getOperationSettings(), clientContext);
-    deleteOperationCallable =
-        callableFactory.createUnaryCallable(
-            deleteOperationTransportSettings, settings.deleteOperationSettings(), clientContext);
-    cancelOperationCallable =
-        callableFactory.createUnaryCallable(
-            cancelOperationTransportSettings, settings.cancelOperationSettings(), clientContext);
-
-    longRunningClient =
-        new HttpJsonLongRunningClient<>(
-            getOperationCallable,
-            getOperationMethodDescriptor.getOperationSnapshotFactory(),
-            getOperationMethodDescriptor.getPollingRequestFactory());
-
-    backgroundResources = new BackgroundResourceAggregation(clientContext.getBackgroundResources());
-  }
-
-  private static <RequestT extends Message, ResponseT>
-      ApiMethodDescriptor<RequestT, ResponseT> getApiVersionedMethodDescriptor(
-          ApiMethodDescriptor<RequestT, ResponseT> methodDescriptor, String apiVersion) {
-    if (apiVersion == null) {
-      return methodDescriptor;
-    }
-
-    ApiMethodDescriptor.Builder<RequestT, ResponseT> descriptorBuilder =
-        methodDescriptor.toBuilder();
-    ProtoMessageRequestFormatter<RequestT> requestFormatter =
-        (ProtoMessageRequestFormatter<RequestT>) descriptorBuilder.getRequestFormatter();
-
-    return descriptorBuilder
-        .setRequestFormatter(
-            requestFormatter.toBuilder().updateRawPath("/v1/", '/' + apiVersion + '/').build())
-        .build();
-  }
-
-  @InternalApi
-  public static List<ApiMethodDescriptor> getMethodDescriptors() {
-    List<ApiMethodDescriptor> methodDescriptors = new ArrayList<>();
-    methodDescriptors.add(listOperationsMethodDescriptor);
-    methodDescriptors.add(getOperationMethodDescriptor);
-    methodDescriptors.add(deleteOperationMethodDescriptor);
-    methodDescriptors.add(cancelOperationMethodDescriptor);
-    return methodDescriptors;
-  }
-
-  @Override
-  public UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable() {
-    return listOperationsCallable;
-  }
-
-  @Override
-  public UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    return listOperationsPagedCallable;
-  }
-
-  @Override
-  public UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    return getOperationCallable;
-  }
-
-  @Override
-  public UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    return deleteOperationCallable;
-  }
-
-  @Override
-  public UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    return cancelOperationCallable;
-  }
-
-  @Override
-  public LongRunningClient longRunningClient() {
-    return longRunningClient;
-  }
-
-  @Override
-  public final void close() {
-    shutdown();
-  }
-
-  @Override
-  public void shutdown() {
-    backgroundResources.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return backgroundResources.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return backgroundResources.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    backgroundResources.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return backgroundResources.awaitTermination(duration, unit);
-  }
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStub.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStub.java
deleted file mode 100644
index bbfec5bde..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStub.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning.stub;
-
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.httpjson.longrunning.OperationsClient.ListOperationsPagedResponse;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Empty;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * Base stub class for the Operations service API.
- *
- * <p>This class is for advanced usage and reflects the underlying API directly.
- */
-public abstract class OperationsStub implements BackgroundResource {
-
-  public UnaryCallable<ListOperationsRequest, ListOperationsPagedResponse>
-      listOperationsPagedCallable() {
-    throw new UnsupportedOperationException("Not implemented: listOperationsPagedCallable()");
-  }
-
-  public UnaryCallable<ListOperationsRequest, ListOperationsResponse> listOperationsCallable() {
-    throw new UnsupportedOperationException("Not implemented: listOperationsCallable()");
-  }
-
-  public UnaryCallable<GetOperationRequest, Operation> getOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: getOperationCallable()");
-  }
-
-  public UnaryCallable<DeleteOperationRequest, Empty> deleteOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: deleteOperationCallable()");
-  }
-
-  public UnaryCallable<CancelOperationRequest, Empty> cancelOperationCallable() {
-    throw new UnsupportedOperationException("Not implemented: cancelOperationCallable()");
-  }
-
-  public LongRunningClient longRunningClient() {
-    throw new UnsupportedOperationException("Not implemented: longRunningClient()");
-  }
-
-  @Override
-  public abstract void close();
-}
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStubSettings.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStubSettings.java
deleted file mode 100644
index 5f327a109..000000000
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/longrunning/stub/OperationsStubSettings.java
+++ /dev/null
@@ -1,425 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning.stub;
-
-import static com.google.api.gax.httpjson.longrunning.OperationsClient.ListOperationsPagedResponse;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.core.GaxProperties;
-import com.google.api.gax.core.GoogleCredentialsProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.httpjson.GaxHttpJsonProperties;
-import com.google.api.gax.httpjson.HttpJsonTransportChannel;
-import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.PageContext;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.PagedListDescriptor;
-import com.google.api.gax.rpc.PagedListResponseFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StubSettings;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Lists;
-import com.google.longrunning.CancelOperationRequest;
-import com.google.longrunning.DeleteOperationRequest;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import java.util.List;
-import org.threeten.bp.Duration;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-/**
- * Settings class to configure an instance of {@link OperationsStub}.
- *
- * <p>The default instance has everything set to sensible defaults:
- *
- * <ul>
- *   <li>The default service address (longrunning.googleapis.com) and default port (443) are used.
- *   <li>Credentials are acquired automatically through Application Default Credentials.
- *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
- * </ul>
- *
- * <p>The builder of this class is recursive, so contained classes are themselves builders. When
- * build() is called, the tree of builders is called to create the complete settings object.
- *
- * <p>For example, to set the total timeout of getOperation to 30 seconds:
- *
- * <pre>{@code
- * OperationsStubSettings.Builder operationsSettingsBuilder = OperationsStubSettings.newBuilder();
- * operationsSettingsBuilder
- *     .getOperationSettings()
- *     .setRetrySettings(
- *         operationsSettingsBuilder
- *             .getOperationSettings()
- *             .getRetrySettings()
- *             .toBuilder()
- *             .setTotalTimeout(Duration.ofSeconds(30))
- *             .build());
- * OperationsStubSettings operationsSettings = operationsSettingsBuilder.build();
- * }</pre>
- */
-public class OperationsStubSettings extends StubSettings<OperationsStubSettings> {
-  /** The default scopes of the service. */
-  private static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
-      ImmutableList.<String>builder().build();
-
-  private final PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings;
-  private final UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings;
-  private final UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings;
-  private final UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings;
-
-  private static final PagedListDescriptor<ListOperationsRequest, ListOperationsResponse, Operation>
-      LIST_OPERATIONS_PAGE_STR_DESC =
-          new PagedListDescriptor<ListOperationsRequest, ListOperationsResponse, Operation>() {
-            @Override
-            public String emptyToken() {
-              return "";
-            }
-
-            @Override
-            public ListOperationsRequest injectToken(ListOperationsRequest payload, String token) {
-              return ListOperationsRequest.newBuilder(payload).setPageToken(token).build();
-            }
-
-            @Override
-            public ListOperationsRequest injectPageSize(
-                ListOperationsRequest payload, int pageSize) {
-              return ListOperationsRequest.newBuilder(payload).setPageSize(pageSize).build();
-            }
-
-            @Override
-            public Integer extractPageSize(ListOperationsRequest payload) {
-              return payload.getPageSize();
-            }
-
-            @Override
-            public String extractNextToken(ListOperationsResponse payload) {
-              return payload.getNextPageToken();
-            }
-
-            @Override
-            public Iterable<Operation> extractResources(ListOperationsResponse payload) {
-              return payload.getOperationsList() == null
-                  ? ImmutableList.<Operation>of()
-                  : payload.getOperationsList();
-            }
-          };
-
-  private static final PagedListResponseFactory<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      LIST_OPERATIONS_PAGE_STR_FACT =
-          new PagedListResponseFactory<
-              ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>() {
-            @Override
-            public ApiFuture<ListOperationsPagedResponse> getFuturePagedResponse(
-                UnaryCallable<ListOperationsRequest, ListOperationsResponse> callable,
-                ListOperationsRequest request,
-                ApiCallContext context,
-                ApiFuture<ListOperationsResponse> futureResponse) {
-              PageContext<ListOperationsRequest, ListOperationsResponse, Operation> pageContext =
-                  PageContext.create(callable, LIST_OPERATIONS_PAGE_STR_DESC, request, context);
-              return ListOperationsPagedResponse.createAsync(pageContext, futureResponse);
-            }
-          };
-
-  /** Returns the object with the settings used for calls to listOperations. */
-  public PagedCallSettings<
-          ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-      listOperationsSettings() {
-    return listOperationsSettings;
-  }
-
-  /** Returns the object with the settings used for calls to get. */
-  public UnaryCallSettings<GetOperationRequest, Operation> getOperationSettings() {
-    return getOperationSettings;
-  }
-
-  /** Returns the object with the settings used for calls to delete. */
-  public UnaryCallSettings<DeleteOperationRequest, Empty> deleteOperationSettings() {
-    return deleteOperationSettings;
-  }
-
-  /** Returns the object with the settings used for calls to cancel. */
-  public UnaryCallSettings<CancelOperationRequest, Empty> cancelOperationSettings() {
-    return cancelOperationSettings;
-  }
-
-  public OperationsStub createStub() throws IOException {
-    if (getTransportChannelProvider()
-        .getTransportName()
-        .equals(HttpJsonTransportChannel.getHttpJsonTransportName())) {
-      return HttpJsonOperationsStub.create(this);
-    }
-    throw new UnsupportedOperationException(
-        String.format(
-            "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
-  }
-
-  /** Returns a builder for the default ExecutorProvider for this service. */
-  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
-    return InstantiatingExecutorProvider.newBuilder();
-  }
-
-  /** Returns the default service endpoint. */
-  public static String getDefaultEndpoint() {
-    return "longrunning.googleapis.com:443";
-  }
-
-  /** Returns the default mTLS service endpoint. */
-  public static String getDefaultMtlsEndpoint() {
-    return "longrunning.mtls.googleapis.com:443";
-  }
-
-  /** Returns the default service scopes. */
-  public static List<String> getDefaultServiceScopes() {
-    return DEFAULT_SERVICE_SCOPES;
-  }
-
-  /** Returns a builder for the default credentials for this service. */
-  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
-  }
-
-  /** Returns a builder for the default ChannelProvider for this service. */
-  public static InstantiatingHttpJsonChannelProvider.Builder
-      defaultHttpJsonTransportProviderBuilder() {
-    return InstantiatingHttpJsonChannelProvider.newBuilder();
-  }
-
-  public static TransportChannelProvider defaultTransportChannelProvider() {
-    return defaultHttpJsonTransportProviderBuilder().build();
-  }
-
-  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
-    return ApiClientHeaderProvider.newBuilder()
-        .setGeneratedLibToken(
-            "gapic", GaxProperties.getLibraryVersion(OperationsStubSettings.class))
-        .setTransportToken(
-            GaxHttpJsonProperties.getHttpJsonTokenName(),
-            GaxHttpJsonProperties.getHttpJsonVersion());
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder() {
-    return Builder.createDefault();
-  }
-
-  /** Returns a new builder for this class. */
-  public static Builder newBuilder(ClientContext clientContext) {
-    return new Builder(clientContext);
-  }
-
-  /** Returns a builder containing all the values of this settings class. */
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  protected OperationsStubSettings(Builder settingsBuilder) throws IOException {
-    super(settingsBuilder);
-
-    listOperationsSettings = settingsBuilder.listOperationsSettings().build();
-    getOperationSettings = settingsBuilder.getOperationSettings().build();
-    deleteOperationSettings = settingsBuilder.deleteOperationSettings().build();
-    cancelOperationSettings = settingsBuilder.cancelOperationSettings().build();
-  }
-
-  /** Builder for OperationsStubSettings. */
-  public static class Builder extends StubSettings.Builder<OperationsStubSettings, Builder> {
-    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
-    private final PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings;
-    private final UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings;
-    private final UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings;
-    private final UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings;
-    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
-        RETRYABLE_CODE_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
-          ImmutableMap.builder();
-      definitions.put(
-          "retry_policy_0_codes",
-          ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList(StatusCode.Code.UNAVAILABLE)));
-      RETRYABLE_CODE_DEFINITIONS = definitions.build();
-    }
-
-    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
-
-    static {
-      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
-      RetrySettings settings = null;
-      settings =
-          RetrySettings.newBuilder()
-              .setInitialRetryDelay(Duration.ofMillis(500L))
-              .setRetryDelayMultiplier(2.0)
-              .setMaxRetryDelay(Duration.ofMillis(10000L))
-              .setInitialRpcTimeout(Duration.ofMillis(10000L))
-              .setRpcTimeoutMultiplier(1.0)
-              .setMaxRpcTimeout(Duration.ofMillis(10000L))
-              .setTotalTimeout(Duration.ofMillis(10000L))
-              .build();
-      definitions.put("retry_policy_0_params", settings);
-      RETRY_PARAM_DEFINITIONS = definitions.build();
-    }
-
-    protected Builder() {
-      this(((ClientContext) null));
-    }
-
-    protected Builder(ClientContext clientContext) {
-      super(clientContext);
-
-      listOperationsSettings = PagedCallSettings.newBuilder(LIST_OPERATIONS_PAGE_STR_FACT);
-      getOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-      deleteOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-      cancelOperationSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
-
-      unaryMethodSettingsBuilders =
-          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
-              listOperationsSettings,
-              getOperationSettings,
-              deleteOperationSettings,
-              cancelOperationSettings);
-      initDefaults(this);
-    }
-
-    protected Builder(OperationsStubSettings settings) {
-      super(settings);
-
-      listOperationsSettings = settings.listOperationsSettings.toBuilder();
-      getOperationSettings = settings.getOperationSettings.toBuilder();
-      deleteOperationSettings = settings.deleteOperationSettings.toBuilder();
-      cancelOperationSettings = settings.cancelOperationSettings.toBuilder();
-
-      unaryMethodSettingsBuilders =
-          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
-              listOperationsSettings,
-              getOperationSettings,
-              deleteOperationSettings,
-              cancelOperationSettings);
-    }
-
-    private static Builder createDefault() {
-      Builder builder = new Builder(((ClientContext) null));
-
-      builder.setTransportChannelProvider(defaultTransportChannelProvider());
-      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
-      builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
-      builder.setEndpoint(getDefaultEndpoint());
-      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
-      builder.setSwitchToMtlsEndpointAllowed(true);
-
-      return initDefaults(builder);
-    }
-
-    private static Builder initDefaults(Builder builder) {
-      builder
-          .listOperationsSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
-
-      builder
-          .getOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
-
-      builder
-          .deleteOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
-
-      builder
-          .cancelOperationSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
-
-      return builder;
-    }
-
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
-    /**
-     * Applies the given settings updater function to all of the unary API methods in this service.
-     *
-     * <p>Note: This method does not support applying settings to streaming methods.
-     */
-    public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
-      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
-      return this;
-    }
-
-    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
-      return unaryMethodSettingsBuilders;
-    }
-
-    /** Returns the builder for the settings used for calls to listOperations. */
-    public PagedCallSettings.Builder<
-            ListOperationsRequest, ListOperationsResponse, ListOperationsPagedResponse>
-        listOperationsSettings() {
-      return listOperationsSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to get. */
-    public UnaryCallSettings.Builder<GetOperationRequest, Operation> getOperationSettings() {
-      return getOperationSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to delete. */
-    public UnaryCallSettings.Builder<DeleteOperationRequest, Empty> deleteOperationSettings() {
-      return deleteOperationSettings;
-    }
-
-    /** Returns the builder for the settings used for calls to cancel. */
-    public UnaryCallSettings.Builder<CancelOperationRequest, Empty> cancelOperationSettings() {
-      return cancelOperationSettings;
-    }
-
-    @Override
-    public OperationsStubSettings build() throws IOException {
-      return new OperationsStubSettings(this);
-    }
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/GaxHttpJsonPropertiesTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/GaxHttpJsonPropertiesTest.java
deleted file mode 100644
index 487605a62..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/GaxHttpJsonPropertiesTest.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-
-public class GaxHttpJsonPropertiesTest {
-  private static final String X_GOOG_API_CLIENT = "x-goog-api-client";
-
-  @Test
-  public void testDefaultHeaderPattern() {
-    assertTrue(
-        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
-            .matcher("gl-java/1.8_00 gapic/1.2.3-alpha gax/1.5.0 rest/1.7.0")
-            .matches());
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpHeadersUtilsTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpHeadersUtilsTest.java
deleted file mode 100644
index 9c305977d..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpHeadersUtilsTest.java
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-
-import com.google.api.client.http.HttpHeaders;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import java.util.Map;
-import org.junit.Test;
-
-public class HttpHeadersUtilsTest {
-
-  @Test
-  public void testSetHeader() {
-    HttpHeaders headers = new HttpHeaders();
-
-    assertEquals(headers, HttpHeadersUtils.setHeader(headers, "Custom-Header", "CustomHeader"));
-    HttpHeadersUtils.setHeader(headers, "accept", "Accept");
-    HttpHeadersUtils.setHeader(headers, "accept-encoding", "AcceptEncoding");
-    HttpHeadersUtils.setHeader(headers, "Authorization", "Authorization");
-    HttpHeadersUtils.setHeader(headers, "cache-Control", "CacheControl");
-    HttpHeadersUtils.setHeader(headers, "Content-Encoding", "ContentEncoding");
-    HttpHeadersUtils.setHeader(headers, "Content-Length", "123");
-    HttpHeadersUtils.setHeader(headers, "Content-MD5", "ContentMD5");
-    HttpHeadersUtils.setHeader(headers, "Content-Range", "ContentRange");
-    HttpHeadersUtils.setHeader(headers, "Content-Type", "ContentType");
-    HttpHeadersUtils.setHeader(headers, "Cookie", "Cookie");
-    HttpHeadersUtils.setHeader(headers, "Date", "Date");
-    HttpHeadersUtils.setHeader(headers, "ETag", "ETag");
-    HttpHeadersUtils.setHeader(headers, "Expires", "Expires");
-    HttpHeadersUtils.setHeader(headers, "If-Modified-Since", "IfModifiedSince");
-    HttpHeadersUtils.setHeader(headers, "If-Match", "IfMatch");
-    HttpHeadersUtils.setHeader(headers, "If-None-Match", "IfNoneMatch");
-    HttpHeadersUtils.setHeader(headers, "If-Unmodified-Since", "IfUnmodifiedSince");
-    HttpHeadersUtils.setHeader(headers, "If-Range", "IfRange");
-    HttpHeadersUtils.setHeader(headers, "Last-Modified", "LastModified");
-    HttpHeadersUtils.setHeader(headers, "Location", "Location");
-    HttpHeadersUtils.setHeader(headers, "Mime-Version", "MimeVersion");
-    HttpHeadersUtils.setHeader(headers, "Range", "Range");
-    HttpHeadersUtils.setHeader(headers, "Retry-After", "RetryAfter");
-    HttpHeadersUtils.setHeader(headers, "User-Agent", "UserAgent");
-    HttpHeadersUtils.setHeader(headers, "WWW-Authenticate", "Authenticate");
-    HttpHeadersUtils.setHeader(headers, "Age", "456");
-
-    assertEquals("CustomHeader", headers.get("Custom-Header"));
-    assertEquals("CustomHeader", headers.get("custom-header"));
-    assertEquals("Accept", headers.getAccept());
-    assertEquals("AcceptEncoding", headers.getAcceptEncoding());
-    assertEquals("Authorization", headers.getAuthorization());
-    assertEquals("CacheControl", headers.getCacheControl());
-    assertEquals("ContentEncoding", headers.getContentEncoding());
-    assertEquals(Long.valueOf(123L), headers.getContentLength());
-    assertEquals("ContentMD5", headers.getContentMD5());
-    assertEquals("ContentRange", headers.getContentRange());
-    assertEquals("ContentType", headers.getContentType());
-    assertEquals("Cookie", headers.getCookie());
-    assertEquals("Date", headers.getDate());
-    assertEquals("ETag", headers.getETag());
-    assertEquals("Expires", headers.getExpires());
-    assertEquals("IfModifiedSince", headers.getIfModifiedSince());
-    assertEquals("IfMatch", headers.getIfMatch());
-    assertEquals("IfNoneMatch", headers.getIfNoneMatch());
-    assertEquals("IfUnmodifiedSince", headers.getIfUnmodifiedSince());
-    assertEquals("IfRange", headers.getIfRange());
-    assertEquals("LastModified", headers.getLastModified());
-    assertEquals("Location", headers.getLocation());
-    assertEquals("MimeVersion", headers.getMimeVersion());
-    assertEquals("Range", headers.getRange());
-    assertEquals("RetryAfter", headers.getRetryAfter());
-    assertEquals("UserAgent", headers.getUserAgent());
-    assertEquals(ImmutableList.of("UserAgent"), headers.get("User-Agent"));
-    assertEquals(ImmutableList.of("UserAgent"), headers.get("user-agent"));
-    assertEquals("Authenticate", headers.getAuthenticate());
-    assertEquals(Long.valueOf(456L), headers.getAge());
-  }
-
-  @Test
-  public void testSetHeaders() {
-    HttpHeaders headers = new HttpHeaders();
-
-    Map<String, String> headersMap =
-        ImmutableMap.of(
-            "Custom-Header", "CustomHeader", "accept", "Accept", "Content-Length", "123");
-
-    assertEquals(headers, HttpHeadersUtils.setHeaders(headers, headersMap));
-
-    assertEquals("CustomHeader", headers.get("Custom-Header"));
-    assertEquals("Accept", headers.getAccept());
-    assertEquals(Long.valueOf(123L), headers.getContentLength());
-  }
-
-  @Test
-  public void testGetUserAgentValue() {
-    Map<String, String> headersMap =
-        ImmutableMap.of(
-            "Custom-Header", "CustomHeader", "User-Agent", "this is me", "accept", "Accept");
-
-    assertEquals("this is me", HttpHeadersUtils.getUserAgentValue(headersMap));
-
-    headersMap = ImmutableMap.of("Custom-Header", "CustomHeader", "accept", "Accept");
-    assertNull(HttpHeadersUtils.getUserAgentValue(headersMap));
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallContextTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallContextTest.java
deleted file mode 100644
index fc872d352..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallContextTest.java
+++ /dev/null
@@ -1,274 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.truth.Truth;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class HttpJsonCallContextTest {
-
-  @Test
-  public void testNullToSelfWrongType() {
-    try {
-      HttpJsonCallContext.createDefault().nullToSelf(FakeCallContext.createDefault());
-      Assert.fail("HttpJsonCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of HttpJsonCallContext");
-    }
-  }
-
-  @Test
-  public void testWithCredentials() {
-    Credentials credentials = Mockito.mock(Credentials.class);
-    HttpJsonCallContext emptyContext = HttpJsonCallContext.createDefault();
-    assertNull(emptyContext.getCredentials());
-    HttpJsonCallContext context = emptyContext.withCredentials(credentials);
-    assertNotNull(context.getCredentials());
-  }
-
-  @Test
-  public void testWithTransportChannel() {
-    ManagedHttpJsonChannel channel = Mockito.mock(ManagedHttpJsonChannel.class);
-
-    HttpJsonCallContext context =
-        HttpJsonCallContext.createDefault()
-            .withTransportChannel(
-                HttpJsonTransportChannel.newBuilder().setManagedChannel(channel).build());
-    Truth.assertThat(context.getChannel()).isSameInstanceAs(channel);
-  }
-
-  @Test
-  public void testWithTransportChannelWrongType() {
-    try {
-      FakeChannel channel = new FakeChannel();
-      HttpJsonCallContext.createDefault()
-          .withTransportChannel(FakeTransportChannel.create(channel));
-      Assert.fail("HttpJsonCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected).hasMessageThat().contains("Expected HttpJsonTransportChannel");
-    }
-  }
-
-  @Test
-  public void testMergeWrongType() {
-    try {
-      HttpJsonCallContext.createDefault().merge(FakeCallContext.createDefault());
-      Assert.fail("HttpJsonCallContext should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of HttpJsonCallContext");
-    }
-  }
-
-  @Test
-  public void testWithTimeout() {
-    assertNull(HttpJsonCallContext.createDefault().withTimeout(null).getTimeout());
-  }
-
-  @Test
-  public void testWithNegativeTimeout() {
-    assertNull(
-        HttpJsonCallContext.createDefault().withTimeout(Duration.ofSeconds(-1L)).getTimeout());
-  }
-
-  @Test
-  public void testWithZeroTimeout() {
-    assertNull(
-        HttpJsonCallContext.createDefault().withTimeout(Duration.ofSeconds(0L)).getTimeout());
-  }
-
-  @Test
-  public void testWithShorterTimeout() {
-    HttpJsonCallContext ctxWithLongTimeout =
-        HttpJsonCallContext.createDefault().withTimeout(Duration.ofSeconds(10));
-
-    // Sanity check
-    Truth.assertThat(ctxWithLongTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(10));
-
-    // Shorten the timeout and make sure it changed
-    HttpJsonCallContext ctxWithShorterTimeout =
-        ctxWithLongTimeout.withTimeout(Duration.ofSeconds(5));
-    Truth.assertThat(ctxWithShorterTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-  }
-
-  @Test
-  public void testWithLongerTimeout() {
-    HttpJsonCallContext ctxWithShortTimeout =
-        HttpJsonCallContext.createDefault().withTimeout(Duration.ofSeconds(5));
-
-    // Sanity check
-    Truth.assertThat(ctxWithShortTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-
-    // Try to extend the timeout and verify that it was ignored
-    HttpJsonCallContext ctxWithUnchangedTimeout =
-        ctxWithShortTimeout.withTimeout(Duration.ofSeconds(10));
-    Truth.assertThat(ctxWithUnchangedTimeout.getTimeout()).isEqualTo(Duration.ofSeconds(5));
-  }
-
-  @Test
-  public void testMergeWithNullTimeout() {
-    Duration timeout = Duration.ofSeconds(10);
-    HttpJsonCallContext baseContext = HttpJsonCallContext.createDefault().withTimeout(timeout);
-
-    HttpJsonCallContext defaultOverlay = HttpJsonCallContext.createDefault();
-    Truth.assertThat(baseContext.merge(defaultOverlay).getTimeout()).isEqualTo(timeout);
-
-    HttpJsonCallContext explicitNullOverlay = HttpJsonCallContext.createDefault().withTimeout(null);
-    Truth.assertThat(baseContext.merge(explicitNullOverlay).getTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithTimeout() {
-    Duration timeout = Duration.ofSeconds(19);
-    HttpJsonCallContext ctx1 = HttpJsonCallContext.createDefault();
-    HttpJsonCallContext ctx2 = HttpJsonCallContext.createDefault().withTimeout(timeout);
-
-    Truth.assertThat(ctx1.merge(ctx2).getTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void testMergeWithTracer() {
-    ApiTracer explicitTracer = Mockito.mock(ApiTracer.class);
-    HttpJsonCallContext ctxWithExplicitTracer =
-        HttpJsonCallContext.createDefault().withTracer(explicitTracer);
-
-    HttpJsonCallContext ctxWithDefaultTracer = HttpJsonCallContext.createDefault();
-    ApiTracer defaultTracer = ctxWithDefaultTracer.getTracer();
-
-    // Explicit tracer overrides the default tracer.
-    Truth.assertThat(ctxWithDefaultTracer.merge(ctxWithExplicitTracer).getTracer())
-        .isSameInstanceAs(explicitTracer);
-
-    // Default tracer does not override an explicit tracer.
-    Truth.assertThat(ctxWithExplicitTracer.merge(ctxWithDefaultTracer).getTracer())
-        .isSameInstanceAs(explicitTracer);
-
-    // Default tracer does not override another default tracer.
-    Truth.assertThat(ctxWithDefaultTracer.merge(HttpJsonCallContext.createDefault()).getTracer())
-        .isSameInstanceAs(defaultTracer);
-  }
-
-  @Test
-  public void testWithRetrySettings() {
-    RetrySettings retrySettings = Mockito.mock(RetrySettings.class);
-    HttpJsonCallContext emptyContext = HttpJsonCallContext.createDefault();
-    assertNull(emptyContext.getRetrySettings());
-    HttpJsonCallContext context = emptyContext.withRetrySettings(retrySettings);
-    assertNotNull(context.getRetrySettings());
-  }
-
-  @Test
-  public void testWithRetryableCodes() {
-    Set<StatusCode.Code> codes = Collections.singleton(StatusCode.Code.UNAVAILABLE);
-    HttpJsonCallContext emptyContext = HttpJsonCallContext.createDefault();
-    assertNull(emptyContext.getRetryableCodes());
-    HttpJsonCallContext context = emptyContext.withRetryableCodes(codes);
-    assertNotNull(context.getRetryableCodes());
-  }
-
-  @Test
-  public void testWithExtraHeaders() {
-    Map<String, List<String>> headers = ImmutableMap.of("k", Arrays.asList("v"));
-    ApiCallContext emptyContext = HttpJsonCallContext.createDefault();
-    assertTrue(emptyContext.getExtraHeaders().isEmpty());
-    ApiCallContext context = emptyContext.withExtraHeaders(headers);
-    assertEquals(headers, context.getExtraHeaders());
-  }
-
-  @Test
-  public void testWithOptions() {
-    ApiCallContext emptyCallContext = HttpJsonCallContext.createDefault();
-    ApiCallContext.Key<String> contextKey1 = ApiCallContext.Key.create("testKey1");
-    ApiCallContext.Key<String> contextKey2 = ApiCallContext.Key.create("testKey2");
-    String testContext1 = "test1";
-    String testContext2 = "test2";
-    String testContextOverwrite = "test1Overwrite";
-    ApiCallContext context =
-        emptyCallContext
-            .withOption(contextKey1, testContext1)
-            .withOption(contextKey2, testContext2);
-    assertEquals(testContext1, context.getOption(contextKey1));
-    assertEquals(testContext2, context.getOption(contextKey2));
-    ApiCallContext newContext = context.withOption(contextKey1, testContextOverwrite);
-    assertEquals(testContextOverwrite, newContext.getOption(contextKey1));
-  }
-
-  @Test
-  public void testMergeOptions() {
-    ApiCallContext emptyCallContext = HttpJsonCallContext.createDefault();
-    ApiCallContext.Key<String> contextKey1 = ApiCallContext.Key.create("testKey1");
-    ApiCallContext.Key<String> contextKey2 = ApiCallContext.Key.create("testKey2");
-    ApiCallContext.Key<String> contextKey3 = ApiCallContext.Key.create("testKey3");
-    String testContext1 = "test1";
-    String testContext2 = "test2";
-    String testContext3 = "test3";
-    String testContextOverwrite = "test1Overwrite";
-    ApiCallContext context1 =
-        emptyCallContext
-            .withOption(contextKey1, testContext1)
-            .withOption(contextKey2, testContext2);
-    ApiCallContext context2 =
-        emptyCallContext
-            .withOption(contextKey1, testContextOverwrite)
-            .withOption(contextKey3, testContext3);
-    ApiCallContext mergedContext = context1.merge(context2);
-    assertEquals(testContextOverwrite, mergedContext.getOption(contextKey1));
-    assertEquals(testContext2, mergedContext.getOption(contextKey2));
-    assertEquals(testContext3, mergedContext.getOption(contextKey3));
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallableFactoryTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallableFactoryTest.java
deleted file mode 100644
index 4d0785f24..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonCallableFactoryTest.java
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-import static com.google.common.truth.Truth.assertWithMessage;
-
-import com.google.api.client.http.HttpMethods;
-import com.google.api.gax.tracing.SpanName;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class HttpJsonCallableFactoryTest {
-  @Test
-  public void testGetSpanName() {
-    Map<String, SpanName> validNames =
-        ImmutableMap.of(
-            "compute.projects.disableXpnHost", SpanName.of("compute.projects", "disableXpnHost"),
-            "client.method", SpanName.of("client", "method"));
-
-    for (Entry<String, SpanName> entry : validNames.entrySet()) {
-      @SuppressWarnings("unchecked")
-      ApiMethodDescriptor<?, ?> descriptor =
-          ApiMethodDescriptor.newBuilder()
-              .setFullMethodName(entry.getKey())
-              .setHttpMethod(HttpMethods.POST)
-              .setRequestFormatter(Mockito.mock(HttpRequestFormatter.class))
-              .setResponseParser(Mockito.mock(HttpResponseParser.class))
-              .build();
-
-      SpanName actualSpanName = HttpJsonCallableFactory.getSpanName(descriptor);
-      assertThat(actualSpanName).isEqualTo(entry.getValue());
-    }
-  }
-
-  @Test
-  public void testGetSpanNameInvalid() {
-    List<String> invalidNames = ImmutableList.of("no_split", ".no_client");
-
-    for (String invalidName : invalidNames) {
-      @SuppressWarnings("unchecked")
-      ApiMethodDescriptor<?, ?> descriptor =
-          ApiMethodDescriptor.newBuilder()
-              .setFullMethodName(invalidName)
-              .setHttpMethod(HttpMethods.POST)
-              .setRequestFormatter(Mockito.mock(HttpRequestFormatter.class))
-              .setResponseParser(Mockito.mock(HttpResponseParser.class))
-              .build();
-
-      IllegalArgumentException actualError = null;
-      try {
-        SpanName spanName = HttpJsonCallableFactory.getSpanName(descriptor);
-        assertWithMessage(
-                "Invalid method descriptor should not have a valid span name: %s should not generate the spanName: %s",
-                invalidName, spanName)
-            .fail();
-      } catch (IllegalArgumentException e) {
-        actualError = e;
-      }
-      assertThat(actualError).isNotNull();
-    }
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonClientInterceptorTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonClientInterceptorTest.java
deleted file mode 100644
index 9a27be86f..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonClientInterceptorTest.java
+++ /dev/null
@@ -1,233 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.httpjson.ForwardingHttpJsonClientCall.SimpleForwardingHttpJsonClientCall;
-import com.google.api.gax.httpjson.ForwardingHttpJsonClientCallListener.SimpleForwardingHttpJsonClientCallListener;
-import com.google.api.gax.httpjson.testing.MockHttpService;
-import com.google.protobuf.Field;
-import com.google.protobuf.Field.Cardinality;
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Before;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class HttpJsonClientInterceptorTest {
-
-  private static final int NUM_RETRIES = 10;
-  private static final int BUSY_WAIT_TIME_IN_MS = 1000;
-
-  private static class CapturingClientInterceptor implements HttpJsonClientInterceptor {
-    // Manually capturing arguments instead of using Mockito. This is intentional, as this
-    // specific test interceptor class represents a typical interceptor implementation. Doing the
-    // same with mocks will simply make this whole test less readable.
-    private volatile HttpJsonMetadata capturedResponseHeaders;
-    private volatile Object capturedMessage;
-    private volatile int capturedStatusCode;
-
-    @Override
-    public <RequestT, ResponseT> HttpJsonClientCall<RequestT, ResponseT> interceptCall(
-        ApiMethodDescriptor<RequestT, ResponseT> method,
-        HttpJsonCallOptions callOptions,
-        HttpJsonChannel next) {
-      HttpJsonClientCall<RequestT, ResponseT> call = next.newCall(method, callOptions);
-      return new SimpleForwardingHttpJsonClientCall<RequestT, ResponseT>(call) {
-        @Override
-        public void start(Listener<ResponseT> responseListener, HttpJsonMetadata requestHeaders) {
-          Listener<ResponseT> forwardingResponseListener =
-              new SimpleForwardingHttpJsonClientCallListener<ResponseT>(responseListener) {
-                @Override
-                public void onHeaders(HttpJsonMetadata responseHeaders) {
-                  capturedResponseHeaders = responseHeaders;
-                  super.onHeaders(responseHeaders);
-                }
-
-                @Override
-                public void onMessage(ResponseT message) {
-                  capturedMessage = message;
-                  super.onMessage(message);
-                }
-
-                @Override
-                public void onClose(int statusCode, HttpJsonMetadata trailers) {
-                  capturedStatusCode = statusCode;
-                  super.onClose(statusCode, trailers);
-                }
-              };
-
-          super.start(forwardingResponseListener, requestHeaders);
-        }
-      };
-    }
-  }
-
-  private static final ApiMethodDescriptor<Field, Field> FAKE_METHOD_DESCRIPTOR =
-      ApiMethodDescriptor.<Field, Field>newBuilder()
-          .setFullMethodName("google.cloud.v1.Fake/FakeMethod")
-          .setHttpMethod("POST")
-          .setRequestFormatter(
-              ProtoMessageRequestFormatter.<Field>newBuilder()
-                  .setPath(
-                      "/fake/v1/name/{name}",
-                      request -> {
-                        Map<String, String> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putPathParam(fields, "name", request.getName());
-                        return fields;
-                      })
-                  .setQueryParamsExtractor(
-                      request -> {
-                        Map<String, List<String>> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putQueryParam(fields, "number", request.getNumber());
-                        return fields;
-                      })
-                  .setRequestBodyExtractor(
-                      request ->
-                          ProtoRestSerializer.create()
-                              .toBody("*", request.toBuilder().clearName().build(), false))
-                  .build())
-          .setResponseParser(
-              ProtoMessageResponseParser.<Field>newBuilder()
-                  .setDefaultInstance(Field.getDefaultInstance())
-                  .build())
-          .build();
-
-  private static final MockHttpService MOCK_SERVICE =
-      new MockHttpService(Collections.singletonList(FAKE_METHOD_DESCRIPTOR), "google.com:443");
-
-  private static ExecutorService executorService;
-
-  private CapturingClientInterceptor interceptor;
-  private ManagedHttpJsonChannel channel;
-
-  @BeforeClass
-  public static void initialize() {
-    executorService =
-        Executors.newFixedThreadPool(
-            2,
-            r -> {
-              Thread t = Executors.defaultThreadFactory().newThread(r);
-              t.setDaemon(true);
-              return t;
-            });
-  }
-
-  @AfterClass
-  public static void destroy() {
-    executorService.shutdownNow();
-  }
-
-  @Before
-  public void setUp() throws IOException {
-    interceptor = new CapturingClientInterceptor();
-    channel =
-        InstantiatingHttpJsonChannelProvider.newBuilder()
-            .setEndpoint("google.com:443")
-            .setExecutor(executorService)
-            .setHttpTransport(MOCK_SERVICE)
-            .setHeaderProvider(() -> Collections.singletonMap("header-key", "headerValue"))
-            .setInterceptorProvider(() -> Collections.singletonList(interceptor))
-            .build()
-            .getTransportChannel()
-            .getManagedChannel();
-  }
-
-  @After
-  public void tearDown() {
-    MOCK_SERVICE.reset();
-  }
-
-  @Test
-  public void testCustomInterceptor() throws ExecutionException, InterruptedException {
-    HttpJsonDirectCallable<Field, Field> callable =
-        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);
-
-    HttpJsonCallContext callContext =
-        HttpJsonCallContext.createDefault()
-            .withChannel(channel)
-            .withTimeout(Duration.ofSeconds(30));
-
-    Field request;
-    Field expectedResponse;
-    request =
-        expectedResponse =
-            Field.newBuilder() // "echo" service
-                .setName("imTheBestField")
-                .setNumber(2)
-                .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
-                .setDefaultValue("blah")
-                .build();
-
-    MOCK_SERVICE.addResponse(expectedResponse);
-
-    Field actualResponse = callable.futureCall(request, callContext).get();
-
-    // Test that the interceptors did not affect normal execution
-    assertThat(actualResponse).isEqualTo(expectedResponse);
-    assertThat(MOCK_SERVICE.getRequestPaths().size()).isEqualTo(1);
-    String headerValue = MOCK_SERVICE.getRequestHeaders().get("header-key").iterator().next();
-
-    // Test that internal interceptor worked (the one which inserts headers)
-    assertThat(headerValue).isEqualTo("headerValue");
-
-    // Test that the custom interceptor was called
-    // These two tests cases are guaranteed to respond back by the time `get()` is unblocked
-    assertThat(interceptor.capturedResponseHeaders).isNotNull();
-    assertThat(interceptor.capturedMessage).isEqualTo(request);
-
-    // Attempt to busy wait {NUM_RETRIES} times until the interceptor's `onClose()` is called
-    int attempts = 0;
-    while (interceptor.capturedStatusCode == 0) {
-      Thread.sleep(BUSY_WAIT_TIME_IN_MS);
-      attempts++;
-      if (attempts == NUM_RETRIES) {
-        break;
-      }
-    }
-
-    assertThat(interceptor.capturedStatusCode).isEqualTo(200);
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectCallableTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectCallableTest.java
deleted file mode 100644
index e47719c5c..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectCallableTest.java
+++ /dev/null
@@ -1,222 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.client.http.HttpResponseException;
-import com.google.api.gax.httpjson.testing.MockHttpService;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.protobuf.Field;
-import com.google.protobuf.Field.Cardinality;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class HttpJsonDirectCallableTest {
-
-  private static final ApiMethodDescriptor<Field, Field> FAKE_METHOD_DESCRIPTOR =
-      ApiMethodDescriptor.<Field, Field>newBuilder()
-          .setFullMethodName("google.cloud.v1.Fake/FakeMethod")
-          .setHttpMethod("POST")
-          .setRequestFormatter(
-              ProtoMessageRequestFormatter.<Field>newBuilder()
-                  .setPath(
-                      "/fake/v1/name/{name=bob/*}",
-                      request -> {
-                        Map<String, String> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putPathParam(fields, "name", request.getName());
-                        return fields;
-                      })
-                  .setAdditionalPaths("/fake/v1/name/{name=john/*}")
-                  .setQueryParamsExtractor(
-                      request -> {
-                        Map<String, List<String>> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putQueryParam(fields, "number", request.getNumber());
-                        return fields;
-                      })
-                  .setRequestBodyExtractor(
-                      request ->
-                          ProtoRestSerializer.create()
-                              .toBody("*", request.toBuilder().clearName().build(), false))
-                  .build())
-          .setResponseParser(
-              ProtoMessageResponseParser.<Field>newBuilder()
-                  .setDefaultInstance(Field.getDefaultInstance())
-                  .build())
-          .build();
-
-  private static final MockHttpService MOCK_SERVICE =
-      new MockHttpService(Collections.singletonList(FAKE_METHOD_DESCRIPTOR), "google.com:443");
-
-  private final ManagedHttpJsonChannel channel =
-      new ManagedHttpJsonInterceptorChannel(
-          ManagedHttpJsonChannel.newBuilder()
-              .setEndpoint("google.com:443")
-              .setExecutor(executorService)
-              .setHttpTransport(MOCK_SERVICE)
-              .build(),
-          new HttpJsonHeaderInterceptor(Collections.singletonMap("header-key", "headerValue")));
-
-  private static ExecutorService executorService;
-
-  @BeforeClass
-  public static void initialize() {
-    executorService =
-        Executors.newFixedThreadPool(
-            2,
-            r -> {
-              Thread t = Executors.defaultThreadFactory().newThread(r);
-              t.setDaemon(true);
-              return t;
-            });
-  }
-
-  @AfterClass
-  public static void destroy() {
-    executorService.shutdownNow();
-  }
-
-  @After
-  public void tearDown() {
-    MOCK_SERVICE.reset();
-  }
-
-  @Test
-  public void testSuccessfulUnaryResponse() throws ExecutionException, InterruptedException {
-    HttpJsonDirectCallable<Field, Field> callable =
-        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);
-
-    HttpJsonCallContext callContext =
-        HttpJsonCallContext.createDefault()
-            .withChannel(channel)
-            .withTimeout(Duration.ofSeconds(30));
-
-    Field request;
-    Field expectedResponse;
-    request = expectedResponse = createTestMessage();
-
-    MOCK_SERVICE.addResponse(expectedResponse);
-
-    Field actualResponse = callable.futureCall(request, callContext).get();
-
-    assertThat(actualResponse).isEqualTo(expectedResponse);
-    assertThat(MOCK_SERVICE.getRequestPaths().size()).isEqualTo(1);
-    String headerValue = MOCK_SERVICE.getRequestHeaders().get("header-key").iterator().next();
-    assertThat(headerValue).isEqualTo("headerValue");
-  }
-
-  @Test
-  public void testErrorUnaryResponse() throws InterruptedException {
-    HttpJsonDirectCallable<Field, Field> callable =
-        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);
-
-    HttpJsonCallContext callContext = HttpJsonCallContext.createDefault().withChannel(channel);
-
-    ApiException exception =
-        ApiExceptionFactory.createException(
-            new Exception(), FakeStatusCode.of(Code.NOT_FOUND), false);
-    MOCK_SERVICE.addException(exception);
-
-    try {
-      callable.futureCall(createTestMessage(), callContext).get();
-      Assert.fail("No exception raised");
-    } catch (ExecutionException e) {
-      HttpResponseException respExp = (HttpResponseException) e.getCause();
-      assertThat(respExp.getStatusCode()).isEqualTo(400);
-      assertThat(respExp.getContent()).isEqualTo(exception.toString());
-    }
-  }
-
-  @Test
-  public void testErrorNullContentSuccessfulResponse() throws InterruptedException {
-    HttpJsonDirectCallable<Field, Field> callable =
-        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);
-
-    HttpJsonCallContext callContext = HttpJsonCallContext.createDefault().withChannel(channel);
-
-    MOCK_SERVICE.addNullResponse();
-
-    try {
-      callable.futureCall(createTestMessage(), callContext).get();
-      Assert.fail("No exception raised");
-    } catch (ExecutionException e) {
-      HttpJsonStatusRuntimeException respExp = (HttpJsonStatusRuntimeException) e.getCause();
-      assertThat(respExp.getStatusCode()).isEqualTo(200);
-      assertThat(respExp.getCause().getMessage())
-          .isEqualTo("Both response message and response exception were null");
-    }
-  }
-
-  @Test
-  public void testErrorNullContentFailedResponse() throws InterruptedException {
-    HttpJsonDirectCallable<Field, Field> callable =
-        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);
-
-    HttpJsonCallContext callContext = HttpJsonCallContext.createDefault().withChannel(channel);
-    MOCK_SERVICE.addNullResponse(400);
-
-    try {
-      callable.futureCall(createTestMessage(), callContext).get();
-      Assert.fail("No exception raised");
-    } catch (ExecutionException e) {
-      HttpResponseException respExp = (HttpResponseException) e.getCause();
-      assertThat(respExp.getStatusCode()).isEqualTo(400);
-      assertThat(respExp.getContent()).isNull();
-    }
-  }
-
-  private Field createTestMessage() {
-    return Field.newBuilder() // "echo" service
-        .setName("john/imTheBestField")
-        .setNumber(2)
-        .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
-        .setDefaultValue("blah")
-        .build();
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallableTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallableTest.java
deleted file mode 100644
index fe0240602..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonDirectServerStreamingCallableTest.java
+++ /dev/null
@@ -1,365 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.httpjson.ApiMethodDescriptor.MethodType;
-import com.google.api.gax.httpjson.testing.MockHttpService;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStream;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StateCheckingResponseObserver;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.StreamController;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.type.Color;
-import com.google.type.Money;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class HttpJsonDirectServerStreamingCallableTest {
-  private static final ApiMethodDescriptor<Color, Money> METHOD_SERVER_STREAMING_RECOGNIZE =
-      ApiMethodDescriptor.<Color, Money>newBuilder()
-          .setFullMethodName("google.cloud.v1.Fake/ServerStreamingRecognize")
-          .setHttpMethod("POST")
-          .setRequestFormatter(
-              ProtoMessageRequestFormatter.<Color>newBuilder()
-                  .setPath(
-                      "/fake/v1/recognize/{blue}",
-                      request -> {
-                        Map<String, String> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putPathParam(fields, "blue", request.getBlue());
-                        return fields;
-                      })
-                  .setQueryParamsExtractor(
-                      request -> {
-                        Map<String, List<String>> fields = new HashMap<>();
-                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                        serializer.putQueryParam(fields, "red", request.getRed());
-                        return fields;
-                      })
-                  .setRequestBodyExtractor(
-                      request ->
-                          ProtoRestSerializer.create()
-                              .toBody(
-                                  "*", request.toBuilder().clearBlue().clearRed().build(), false))
-                  .build())
-          .setResponseParser(
-              ProtoMessageResponseParser.<Money>newBuilder()
-                  .setDefaultInstance(Money.getDefaultInstance())
-                  .build())
-          .setType(MethodType.SERVER_STREAMING)
-          .build();
-
-  private static final MockHttpService MOCK_SERVICE =
-      new MockHttpService(
-          Collections.singletonList(METHOD_SERVER_STREAMING_RECOGNIZE), "google.com:443");
-
-  private static final Color DEFAULT_REQUEST = Color.newBuilder().setRed(0.5f).build();
-  private static final Color ASYNC_REQUEST = DEFAULT_REQUEST.toBuilder().setGreen(1000).build();
-  private static final Color ERROR_REQUEST = Color.newBuilder().setRed(-1).build();
-  private static final Money DEFAULT_RESPONSE =
-      Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-  private static final Money DEFAULTER_RESPONSE =
-      Money.newBuilder().setCurrencyCode("UAH").setUnits(255).build();
-
-  private ClientContext clientContext;
-  private ServerStreamingCallSettings<Color, Money> streamingCallSettings;
-  private ServerStreamingCallable<Color, Money> streamingCallable;
-
-  private static ExecutorService executorService;
-
-  @BeforeClass
-  public static void initialize() {
-    executorService = Executors.newFixedThreadPool(2);
-  }
-
-  @AfterClass
-  public static void destroy() {
-    executorService.shutdownNow();
-  }
-
-  @Before
-  public void setUp() {
-    ManagedHttpJsonChannel channel =
-        new ManagedHttpJsonInterceptorChannel(
-            ManagedHttpJsonChannel.newBuilder()
-                .setEndpoint("google.com:443")
-                .setExecutor(executorService)
-                .setHttpTransport(MOCK_SERVICE)
-                .build(),
-            new HttpJsonHeaderInterceptor(Collections.singletonMap("header-key", "headerValue")));
-
-    clientContext =
-        ClientContext.newBuilder()
-            .setTransportChannel(HttpJsonTransportChannel.create(channel))
-            .setDefaultCallContext(HttpJsonCallContext.of(channel, HttpJsonCallOptions.DEFAULT))
-            .build();
-    streamingCallSettings = ServerStreamingCallSettings.<Color, Money>newBuilder().build();
-    streamingCallable =
-        HttpJsonCallableFactory.createServerStreamingCallable(
-            HttpJsonCallSettings.create(METHOD_SERVER_STREAMING_RECOGNIZE),
-            streamingCallSettings,
-            clientContext);
-  }
-
-  @After
-  public void tearDown() {
-    MOCK_SERVICE.reset();
-  }
-
-  @Test
-  public void testBadContext() {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    streamingCallable =
-        HttpJsonCallableFactory.createServerStreamingCallable(
-            HttpJsonCallSettings.create(METHOD_SERVER_STREAMING_RECOGNIZE),
-            streamingCallSettings,
-            clientContext
-                .toBuilder()
-                .setDefaultCallContext(FakeCallContext.createDefault())
-                .build());
-
-    CountDownLatch latch = new CountDownLatch(1);
-
-    MoneyObserver observer = new MoneyObserver(true, latch);
-    try {
-      streamingCallable.call(DEFAULT_REQUEST, observer);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("context must be an instance of HttpJsonCallContext");
-    }
-  }
-
-  @Test
-  public void testServerStreamingStart() throws InterruptedException {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(moneyObserver.controller).isNotNull();
-    // wait for the task to complete, otherwise it may interfere with other tests, since they share
-    // the same MockService and unfinished request in this tes may start readind messages designated
-    // for other tests.
-    Truth.assertThat(latch.await(2, TimeUnit.SECONDS)).isTrue();
-  }
-
-  @Test
-  public void testServerStreaming() throws InterruptedException {
-
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE, DEFAULTER_RESPONSE});
-    CountDownLatch latch = new CountDownLatch(3);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
-    Truth.assertThat(latch.getCount()).isEqualTo(0);
-    Truth.assertThat(moneyObserver.error).isNull();
-    Truth.assertThat(moneyObserver.response).isEqualTo(DEFAULTER_RESPONSE);
-  }
-
-  @Test
-  public void testManualFlowControl() throws Exception {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    CountDownLatch latch = new CountDownLatch(2);
-    MoneyObserver moneyObserver = new MoneyObserver(false, latch);
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-
-    Truth.assertThat(latch.await(1000, TimeUnit.MILLISECONDS)).isFalse();
-    Truth.assertWithMessage("Received response before requesting it")
-        .that(moneyObserver.response)
-        .isNull();
-
-    moneyObserver.controller.request(1);
-    Truth.assertThat(latch.await(1000, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.response).isEqualTo(DEFAULT_RESPONSE);
-    Truth.assertThat(moneyObserver.completed).isTrue();
-  }
-
-  @Test
-  public void testCancelClientCall() throws Exception {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(false, latch);
-
-    streamingCallable.call(ASYNC_REQUEST, moneyObserver);
-
-    moneyObserver.controller.cancel();
-    moneyObserver.controller.request(1);
-    Truth.assertThat(latch.await(500, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.error).isInstanceOf(CancellationException.class);
-    Truth.assertThat(moneyObserver.error).hasMessageThat().isEqualTo("User cancelled stream");
-  }
-
-  @Test
-  public void testOnResponseError() throws Throwable {
-    MOCK_SERVICE.addException(404, new RuntimeException("some error"));
-
-    CountDownLatch latch = new CountDownLatch(1);
-    MoneyObserver moneyObserver = new MoneyObserver(true, latch);
-
-    streamingCallable.call(ERROR_REQUEST, moneyObserver);
-    Truth.assertThat(latch.await(1000, TimeUnit.MILLISECONDS)).isTrue();
-
-    Truth.assertThat(moneyObserver.error).isInstanceOf(ApiException.class);
-    Truth.assertThat(((ApiException) moneyObserver.error).getStatusCode().getCode())
-        .isEqualTo(Code.NOT_FOUND);
-    Truth.assertThat(moneyObserver.error)
-        .hasMessageThat()
-        .isEqualTo(
-            "com.google.api.client.http.HttpResponseException: 404\n"
-                + "POST https://google.com:443/fake/v1/recognize/0.0?red=-1.0\n"
-                + "java.lang.RuntimeException: some error");
-  }
-
-  @Test
-  public void testObserverErrorCancelsCall() throws Throwable {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    final RuntimeException expectedCause = new RuntimeException("some error");
-    final SettableApiFuture<Throwable> actualErrorF = SettableApiFuture.create();
-
-    ResponseObserver<Money> moneyObserver =
-        new StateCheckingResponseObserver<Money>() {
-          @Override
-          protected void onStartImpl(StreamController controller) {}
-
-          @Override
-          protected void onResponseImpl(Money response) {
-            throw expectedCause;
-          }
-
-          @Override
-          protected void onErrorImpl(Throwable t) {
-            actualErrorF.set(t);
-          }
-
-          @Override
-          protected void onCompleteImpl() {
-            actualErrorF.set(null);
-          }
-        };
-
-    streamingCallable.call(DEFAULT_REQUEST, moneyObserver);
-    Throwable actualError = actualErrorF.get(11500, TimeUnit.MILLISECONDS);
-
-    Truth.assertThat(actualError).isInstanceOf(ApiException.class);
-    Truth.assertThat(((ApiException) actualError).getStatusCode().getCode())
-        .isEqualTo(StatusCode.Code.CANCELLED);
-
-    // gax httpjson transport layer is responsible for the immediate cancellation
-    Truth.assertThat(actualError.getCause()).isInstanceOf(HttpJsonStatusRuntimeException.class);
-    // and the client error is cause for httpjson transport layer to cancel it
-    Truth.assertThat(actualError.getCause().getCause()).isSameInstanceAs(expectedCause);
-  }
-
-  @Test
-  public void testBlockingServerStreaming() {
-    MOCK_SERVICE.addResponse(new Money[] {DEFAULT_RESPONSE});
-    Color request = Color.newBuilder().setRed(0.5f).build();
-    ServerStream<Money> response = streamingCallable.call(request);
-    List<Money> responseData = Lists.newArrayList(response);
-
-    Money expected = Money.newBuilder().setCurrencyCode("USD").setUnits(127).build();
-    Truth.assertThat(responseData).containsExactly(expected);
-  }
-
-  static class MoneyObserver extends StateCheckingResponseObserver<Money> {
-    private final boolean autoFlowControl;
-    private final CountDownLatch latch;
-
-    volatile StreamController controller;
-    volatile Money response;
-    volatile Throwable error;
-    volatile boolean completed;
-
-    MoneyObserver(boolean autoFlowControl, CountDownLatch latch) {
-      this.autoFlowControl = autoFlowControl;
-      this.latch = latch;
-    }
-
-    @Override
-    protected void onStartImpl(StreamController controller) {
-      this.controller = controller;
-      if (!autoFlowControl) {
-        controller.disableAutoInboundFlowControl();
-      }
-    }
-
-    @Override
-    protected void onResponseImpl(Money value) {
-      response = value;
-      latch.countDown();
-    }
-
-    @Override
-    protected void onErrorImpl(Throwable t) {
-      error = t;
-      latch.countDown();
-    }
-
-    @Override
-    protected void onCompleteImpl() {
-      completed = true;
-      latch.countDown();
-    }
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonLongRunningClientTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonLongRunningClientTest.java
deleted file mode 100644
index 702f327a6..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonLongRunningClientTest.java
+++ /dev/null
@@ -1,146 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertNull;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.protobuf.Option;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class HttpJsonLongRunningClientTest {
-
-  private OperationSnapshotFactory<Option, Field> operationSnapFact;
-  private PollingRequestFactory<Option> pollReqFact;
-
-  @Before
-  public void init() {
-    operationSnapFact =
-        new OperationSnapshotFactory<Option, Field>() {
-          @Override
-          public OperationSnapshot create(final Option request, final Field response) {
-            OperationSnapshot mockOpSnap = mock(OperationSnapshot.class);
-            when(mockOpSnap.getName()).thenReturn(response.getName());
-            return mockOpSnap;
-          }
-        };
-    pollReqFact =
-        new PollingRequestFactory<Option>() {
-          @Override
-          public Option create(String compoundOperationId) {
-            return Option.newBuilder().setName(compoundOperationId).build();
-          }
-        };
-  }
-
-  @Test
-  public void getOperationCallableTest() {
-    UnaryCallable<Option, Field> operationCallable =
-        new UnaryCallable<Option, Field>() {
-          @Override
-          public ApiFuture<Field> futureCall(Option request, ApiCallContext context) {
-            return ApiFutures.immediateFuture(Field.newBuilder().setName("Miami").build());
-          }
-        };
-
-    HttpJsonLongRunningClient<Option, Field> lroClient =
-        new HttpJsonLongRunningClient<Option, Field>(
-            operationCallable, operationSnapFact, pollReqFact);
-    UnaryCallable<String, OperationSnapshot> operationCall = lroClient.getOperationCallable();
-    assertThat(operationCall.call("Chicago").getName()).isEqualTo("Miami");
-  }
-
-  @Test
-  public void getOperationCallableFailTest() {
-    UnaryCallable<Option, Field> operationCallable =
-        new UnaryCallable<Option, Field>() {
-          @Override
-          public ApiFuture<Field> futureCall(Option request, ApiCallContext context) {
-            return ApiFutures.immediateFailedFuture(new RuntimeException("Prague"));
-          }
-        };
-
-    HttpJsonLongRunningClient<Option, Field> lroClient =
-        new HttpJsonLongRunningClient<Option, Field>(
-            operationCallable, operationSnapFact, pollReqFact);
-    UnaryCallable<String, OperationSnapshot> operationCall = lroClient.getOperationCallable();
-    try {
-      operationCall.call("Chicago");
-      Assert.fail("Exception should have been thrown");
-    } catch (RuntimeException e) {
-      Truth.assertThat(e).hasMessageThat().contains("Prague");
-    }
-  }
-
-  @Test
-  public void cancelOperationCallableTest() {
-    UnaryCallable<Option, Field> operationCallable =
-        new UnaryCallable<Option, Field>() {
-          @Override
-          public ApiFuture<Field> futureCall(Option request, ApiCallContext context) {
-            return ApiFutures.immediateFuture(Field.newBuilder().setName("Miami").build());
-          }
-        };
-
-    HttpJsonLongRunningClient<Option, Field> lroClient =
-        new HttpJsonLongRunningClient<Option, Field>(
-            operationCallable, operationSnapFact, pollReqFact);
-    UnaryCallable<String, Void> cancel = lroClient.cancelOperationCallable();
-    assertNull(cancel);
-  }
-
-  @Test
-  public void deleteOperationCallableTest() {
-    UnaryCallable<Option, Field> operationCallable =
-        new UnaryCallable<Option, Field>() {
-          @Override
-          public ApiFuture<Field> futureCall(Option request, ApiCallContext context) {
-            return ApiFutures.immediateFuture(Field.newBuilder().setName("Miami").build());
-          }
-        };
-
-    HttpJsonLongRunningClient<Option, Field> lroClient =
-        new HttpJsonLongRunningClient<Option, Field>(
-            operationCallable, operationSnapFact, pollReqFact);
-    UnaryCallable<String, Void> delete = lroClient.cancelOperationCallable();
-    assertNull(delete);
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallableTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallableTest.java
deleted file mode 100644
index 4b67e0346..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotCallableTest.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.protobuf.Option;
-import java.util.concurrent.ExecutionException;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class HttpJsonOperationSnapshotCallableTest {
-
-  UnaryCallable<Option, Field> innerCallable;
-  OperationSnapshotFactory<Option, Field> operationSnapshotFactory;
-  HttpJsonOperationSnapshotCallable<Option, Field> operationSnapCallable;
-
-  @Before
-  @SuppressWarnings("unchecked")
-  public void init() {
-    innerCallable = (UnaryCallable<Option, Field>) mock(UnaryCallable.class);
-    operationSnapshotFactory =
-        (OperationSnapshotFactory<Option, Field>) mock(OperationSnapshotFactory.class);
-
-    operationSnapCallable =
-        new HttpJsonOperationSnapshotCallable<Option, Field>(
-            innerCallable, operationSnapshotFactory);
-  }
-
-  @Test
-  public void futureCallTest() throws ExecutionException, InterruptedException {
-    Option request = Option.newBuilder().setName("Arizona").build();
-    Field field = Field.newBuilder().setName("Georgia").build();
-    ApiCallContext context = mock(ApiCallContext.class);
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("California")
-            .setMetadata(2)
-            .setDone(true)
-            .setResponse("Florida")
-            .setError(0, "no error")
-            .build();
-
-    SettableApiFuture<Field> settableApiFuture = SettableApiFuture.create();
-    settableApiFuture.set(field);
-
-    when(operationSnapshotFactory.create(request, field)).thenReturn(operationSnapshot);
-    when(innerCallable.futureCall(request, context)).thenReturn(settableApiFuture);
-
-    ApiFuture<OperationSnapshot> futureCall = operationSnapCallable.futureCall(request, context);
-
-    Truth.assertThat(futureCall.get().getName()).isEqualTo("California");
-  }
-
-  @Test
-  public void futureCallTestException() throws InterruptedException {
-    Option request = Option.newBuilder().setName("Arizona").build();
-    Field field = Field.newBuilder().setName("Georgia").build();
-    ApiCallContext context = mock(ApiCallContext.class);
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("California")
-            .setMetadata(2)
-            .setDone(true)
-            .setResponse("Florida")
-            .setError(0, "no error")
-            .build();
-
-    SettableApiFuture<Field> settableApiFuture = SettableApiFuture.create();
-    settableApiFuture.setException(new RuntimeException("Seattle"));
-
-    when(operationSnapshotFactory.create(request, field)).thenReturn(operationSnapshot);
-    when(innerCallable.futureCall(request, context)).thenReturn(settableApiFuture);
-
-    try {
-      operationSnapCallable.futureCall(request, context).get();
-      Assert.fail("Exception should have been thrown");
-    } catch (ExecutionException e) {
-      Truth.assertThat(e).hasMessageThat().contains("Seattle");
-    }
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotTest.java
deleted file mode 100644
index 6ff331c2c..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonOperationSnapshotTest.java
+++ /dev/null
@@ -1,89 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import java.util.ArrayList;
-import org.junit.Test;
-
-public class HttpJsonOperationSnapshotTest {
-
-  @Test
-  public void newBuilderTestNoError() {
-    HttpJsonOperationSnapshot testOperationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("snapshot0")
-            .setMetadata("Los Angeles")
-            .setDone(true)
-            .setResponse("Atlanta")
-            .setError(0, "no error")
-            .build();
-
-    assertEquals("no error", testOperationSnapshot.getErrorMessage());
-    assertEquals(HttpJsonStatusCode.of(Code.OK), testOperationSnapshot.getErrorCode());
-    assertTrue(testOperationSnapshot.isDone());
-  }
-
-  @Test
-  public void newBuilderTestWithError() {
-    HttpJsonOperationSnapshot testOperationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("snapshot1")
-            .setMetadata("Austin")
-            .setDone(true)
-            .setResponse(new ArrayList<Integer>())
-            .setError(403, "Forbidden")
-            .build();
-
-    assertEquals(testOperationSnapshot.getErrorMessage(), "Forbidden");
-    assertEquals(testOperationSnapshot.getErrorCode(), HttpJsonStatusCode.of(403));
-    assertTrue(testOperationSnapshot.isDone());
-  }
-
-  @Test
-  public void newBuilderTestNotDone() {
-    HttpJsonOperationSnapshot testOperationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("snapshot2")
-            .setMetadata("Chicago")
-            .setDone(false)
-            .setResponse(new ArrayList<Integer>())
-            .setError(0, "no error")
-            .build();
-
-    assertEquals("no error", testOperationSnapshot.getErrorMessage());
-    assertEquals(HttpJsonStatusCode.of(Code.OK), testOperationSnapshot.getErrorCode());
-    assertFalse(testOperationSnapshot.isDone());
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonStatusCodeTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonStatusCodeTest.java
deleted file mode 100644
index 7c7664c3b..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonStatusCodeTest.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import java.util.HashSet;
-import java.util.Set;
-import org.junit.Test;
-
-public class HttpJsonStatusCodeTest {
-
-  @Test
-  public void rpcCodeToStatusCodeTest() {
-    Set<Code> allCodes = new HashSet<>();
-    for (com.google.rpc.Code rpcCode : com.google.rpc.Code.values()) {
-      Code statusCode;
-      try {
-        statusCode = HttpJsonStatusCode.rpcCodeToStatusCode(rpcCode);
-      } catch (IllegalArgumentException e) {
-        if (rpcCode != com.google.rpc.Code.UNRECOGNIZED) {
-          fail("Unrecognized com.google.rpc.Code found " + rpcCode);
-        }
-        continue;
-      }
-
-      assertThat(statusCode).isNotNull();
-      allCodes.add(statusCode);
-    }
-
-    assertThat(Code.values()).asList().containsExactlyElementsIn(allCodes);
-  }
-
-  @Test
-  public void httpStatusToStatusCodeTest() {
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(200)).isEqualTo(Code.OK);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(201)).isEqualTo(Code.OK);
-
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(400)).isEqualTo(Code.INVALID_ARGUMENT);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(401)).isEqualTo(Code.UNAUTHENTICATED);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(403)).isEqualTo(Code.PERMISSION_DENIED);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(404)).isEqualTo(Code.NOT_FOUND);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(409)).isEqualTo(Code.ABORTED);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(416)).isEqualTo(Code.OUT_OF_RANGE);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(429)).isEqualTo(Code.RESOURCE_EXHAUSTED);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(499)).isEqualTo(Code.CANCELLED);
-
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(405)).isEqualTo(Code.FAILED_PRECONDITION);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(408)).isEqualTo(Code.FAILED_PRECONDITION);
-
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(500)).isEqualTo(Code.INTERNAL);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(501)).isEqualTo(Code.UNIMPLEMENTED);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(502)).isEqualTo(Code.INTERNAL);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(503)).isEqualTo(Code.UNAVAILABLE);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(504)).isEqualTo(Code.DEADLINE_EXCEEDED);
-
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(100)).isEqualTo(Code.UNKNOWN);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(300)).isEqualTo(Code.UNKNOWN);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(302)).isEqualTo(Code.UNKNOWN);
-    assertThat(HttpJsonStatusCode.httpStatusToStatusCode(600)).isEqualTo(Code.UNKNOWN);
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpRequestRunnableTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpRequestRunnableTest.java
deleted file mode 100644
index f68b11feb..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpRequestRunnableTest.java
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.api.client.http.EmptyContent;
-import com.google.api.client.http.HttpRequest;
-import com.google.api.client.testing.http.MockHttpTransport;
-import com.google.common.truth.Truth;
-import com.google.longrunning.ListOperationsRequest;
-import com.google.protobuf.Empty;
-import com.google.protobuf.Field;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.mockito.Mockito;
-
-public class HttpRequestRunnableTest {
-  private static Field requestMessage;
-  private static final String ENDPOINT = "https://www.googleapis.com/animals/v1/projects";
-  private static HttpRequestFormatter<Field> requestFormatter;
-  private static HttpResponseParser<Empty> responseParser;
-
-  @SuppressWarnings("unchecked")
-  @BeforeClass
-  public static void setUp() {
-    requestMessage =
-        Field.newBuilder()
-            .setName("feline")
-            .setNumber(2)
-            .setDefaultValue("bird")
-            .setJsonName("mouse")
-            .setTypeUrl("small")
-            .build();
-
-    requestFormatter =
-        ProtoMessageRequestFormatter.<Field>newBuilder()
-            .setPath(
-                "/name/{name=*}",
-                request -> {
-                  Map<String, String> fields = new HashMap<>();
-                  ProtoRestSerializer<ListOperationsRequest> serializer =
-                      ProtoRestSerializer.create();
-                  serializer.putPathParam(fields, "name", request.getName());
-                  return fields;
-                })
-            .setQueryParamsExtractor(
-                request -> {
-                  Map<String, List<String>> fields = new LinkedHashMap<>();
-                  ProtoRestSerializer<ListOperationsRequest> serializer =
-                      ProtoRestSerializer.create();
-
-                  serializer.putQueryParam(
-                      fields,
-                      "food",
-                      Arrays.asList(request.getDefaultValue(), request.getJsonName()));
-                  serializer.putQueryParam(fields, "size", request.getTypeUrl());
-                  return fields;
-                })
-            .setRequestBodyExtractor(request -> null)
-            .build();
-
-    responseParser = Mockito.mock(HttpResponseParser.class);
-  }
-
-  @Test
-  public void testRequestUrl() throws IOException {
-    ApiMethodDescriptor<Field, Empty> methodDescriptor =
-        ApiMethodDescriptor.<Field, Empty>newBuilder()
-            .setFullMethodName("house.cat.get")
-            .setHttpMethod(null)
-            .setRequestFormatter(requestFormatter)
-            .setResponseParser(responseParser)
-            .build();
-
-    HttpRequestRunnable<Field, Empty> httpRequestRunnable =
-        new HttpRequestRunnable<>(
-            requestMessage,
-            methodDescriptor,
-            ENDPOINT,
-            HttpJsonCallOptions.newBuilder().build(),
-            new MockHttpTransport(),
-            HttpJsonMetadata.newBuilder().build(),
-            (result) -> {});
-
-    HttpRequest httpRequest = httpRequestRunnable.createHttpRequest();
-    Truth.assertThat(httpRequest.getContent()).isInstanceOf(EmptyContent.class);
-    String expectedUrl = ENDPOINT + "/name/feline" + "?food=bird&food=mouse&size=small";
-    Truth.assertThat(httpRequest.getUrl().toString()).isEqualTo(expectedUrl);
-  }
-
-  @Test
-  public void testRequestUrlUnnormalized() throws IOException {
-    ApiMethodDescriptor<Field, Empty> methodDescriptor =
-        ApiMethodDescriptor.<Field, Empty>newBuilder()
-            .setFullMethodName("house.cat.get")
-            .setHttpMethod("PUT")
-            .setRequestFormatter(requestFormatter)
-            .setResponseParser(responseParser)
-            .build();
-
-    HttpRequestRunnable<Field, Empty> httpRequestRunnable =
-        new HttpRequestRunnable<>(
-            requestMessage,
-            methodDescriptor,
-            "www.googleapis.com/animals/v1/projects",
-            HttpJsonCallOptions.newBuilder().build(),
-            new MockHttpTransport(),
-            HttpJsonMetadata.newBuilder().build(),
-            (result) -> {});
-
-    HttpRequest httpRequest = httpRequestRunnable.createHttpRequest();
-    Truth.assertThat(httpRequest.getContent()).isInstanceOf(EmptyContent.class);
-    String expectedUrl =
-        "https://www.googleapis.com/animals/v1/projects/name/feline?food=bird&food=mouse&size=small";
-    Truth.assertThat(httpRequest.getUrl().toString()).isEqualTo(expectedUrl);
-    Truth.assertThat(httpRequest.getRequestMethod()).isEqualTo("PUT");
-    Truth.assertThat(httpRequest.getHeaders().get("X-HTTP-Method-Override")).isNull();
-  }
-
-  @Test
-  public void testRequestUrlUnnormalizedPatch() throws IOException {
-    ApiMethodDescriptor<Field, Empty> methodDescriptor =
-        ApiMethodDescriptor.<Field, Empty>newBuilder()
-            .setFullMethodName("house.cat.get")
-            .setHttpMethod("PATCH")
-            .setRequestFormatter(requestFormatter)
-            .setResponseParser(responseParser)
-            .build();
-
-    HttpRequestRunnable<Field, Empty> httpRequestRunnable =
-        new HttpRequestRunnable<>(
-            requestMessage,
-            methodDescriptor,
-            "www.googleapis.com/animals/v1/projects",
-            HttpJsonCallOptions.newBuilder().build(),
-            new MockHttpTransport(),
-            HttpJsonMetadata.newBuilder().build(),
-            (result) -> {});
-
-    HttpRequest httpRequest = httpRequestRunnable.createHttpRequest();
-    Truth.assertThat(httpRequest.getContent()).isInstanceOf(EmptyContent.class);
-    String expectedUrl =
-        "https://www.googleapis.com/animals/v1/projects/name/feline?food=bird&food=mouse&size=small";
-    Truth.assertThat(httpRequest.getUrl().toString()).isEqualTo(expectedUrl);
-    Truth.assertThat(httpRequest.getRequestMethod()).isEqualTo("POST");
-    Truth.assertThat(httpRequest.getHeaders().get("X-HTTP-Method-Override")).isEqualTo("PATCH");
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProviderTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProviderTest.java
deleted file mode 100644
index 4061ff8ba..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/InstantiatingHttpJsonChannelProviderTest.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.gax.rpc.TransportChannelProvider;
-import com.google.api.gax.rpc.mtls.AbstractMtlsTransportChannelTest;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import java.io.IOException;
-import java.security.GeneralSecurityException;
-import java.util.Collections;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class InstantiatingHttpJsonChannelProviderTest extends AbstractMtlsTransportChannelTest {
-
-  @Test
-  public void basicTest() throws IOException {
-    String endpoint = "localhost:8080";
-    ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    executor.shutdown();
-
-    TransportChannelProvider provider = InstantiatingHttpJsonChannelProvider.newBuilder().build();
-
-    assertThat(provider.needsEndpoint()).isTrue();
-    provider = provider.withEndpoint(endpoint);
-    assertThat(provider.needsEndpoint()).isFalse();
-
-    assertThat(provider.needsHeaders()).isTrue();
-    provider = provider.withHeaders(Collections.<String, String>emptyMap());
-    assertThat(provider.needsHeaders()).isFalse();
-
-    // Make sure getTransportChannel works without setting executor
-    assertThat(provider.getTransportChannel()).isInstanceOf(HttpJsonTransportChannel.class);
-
-    assertThat(provider.needsExecutor()).isTrue();
-    provider = provider.withExecutor((Executor) executor);
-    assertThat(provider.needsExecutor()).isFalse();
-
-    // Added for code coverage. Remove when withExecutor(ScheduledExecutorService) is removed.
-    assertThat(provider.needsExecutor()).isFalse();
-    provider = provider.withExecutor(executor);
-    assertThat(provider.needsExecutor()).isFalse();
-
-    assertThat(provider.acceptsPoolSize()).isFalse();
-    Exception thrownException = null;
-    try {
-      provider.withPoolSize(1);
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    assertThat(provider.needsCredentials()).isFalse();
-    thrownException = null;
-    try {
-      provider.withCredentials(null);
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    assertEquals(HttpJsonTransportChannel.getHttpJsonTransportName(), provider.getTransportName());
-    assertThat(provider.getTransportChannel()).isInstanceOf(HttpJsonTransportChannel.class);
-
-    // Make sure we can create channels OK.
-    provider.getTransportChannel().shutdownNow();
-  }
-
-  @Override
-  protected Object getMtlsObjectFromTransportChannel(MtlsProvider provider)
-      throws IOException, GeneralSecurityException {
-    InstantiatingHttpJsonChannelProvider channelProvider =
-        InstantiatingHttpJsonChannelProvider.newBuilder()
-            .setEndpoint("localhost:8080")
-            .setMtlsProvider(provider)
-            .setHeaderProvider(Mockito.mock(HeaderProvider.class))
-            .setExecutor(Mockito.mock(Executor.class))
-            .build();
-    return channelProvider.createHttpTransport();
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIteratorTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIteratorTest.java
deleted file mode 100644
index c9836db9a..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageJsonStreamIteratorTest.java
+++ /dev/null
@@ -1,238 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.protobuf.Int64Value;
-import com.google.protobuf.Option;
-import com.google.protobuf.util.JsonFormat;
-import java.io.IOException;
-import java.io.StringReader;
-import org.junit.Test;
-
-public class ProtoMessageJsonStreamIteratorTest {
-
-  @Test
-  public void testEmpty() throws IOException {
-    String jsonData = "[]";
-    ProtoMessageJsonStreamIterator streamIter =
-        new ProtoMessageJsonStreamIterator(new StringReader(jsonData));
-
-    Truth.assertThat(streamIter.hasNext()).isFalse();
-    streamIter.close();
-  }
-
-  @Test
-  public void testSingleElement() throws IOException {
-    Field[] expectedData =
-        new Field[] {
-          Field.newBuilder()
-              .setName("cat")
-              .addOptions(Option.newBuilder().setName("haha").build())
-              .addOptions(Option.newBuilder().setName("hoho").build())
-              .setNumber(1)
-              .setDefaultValue("mew")
-              .build()
-        };
-
-    String jsonData =
-        "[{\n"
-            + "  \"number\": 1,\n"
-            + "  \"name\": \"cat\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"haha\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"hoho\"\n"
-            + "  }],\n"
-            + "  \"defaultValue\": \"mew\"\n"
-            + "}]";
-
-    ProtoMessageJsonStreamIterator streamIter =
-        new ProtoMessageJsonStreamIterator(new StringReader(jsonData));
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    Field.Builder builder = Field.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[0]);
-
-    Truth.assertThat(streamIter.hasNext()).isFalse();
-
-    streamIter.close();
-    // closing a closed iterator should be no-op.
-    streamIter.close();
-  }
-
-  @Test
-  public void testProtobufWrapperObjects() throws IOException {
-    Int64Value[] expectedData =
-        new Int64Value[] {
-          Int64Value.newBuilder().setValue(1234567889999977L).build(),
-          Int64Value.newBuilder().setValue(2234567889999977L).build(),
-          Int64Value.newBuilder().setValue(3234567889999977L).build()
-        };
-
-    String jsonData = "[\"1234567889999977\", \t    \"2234567889999977\",\n\"3234567889999977\"]";
-
-    ProtoMessageJsonStreamIterator streamIter =
-        new ProtoMessageJsonStreamIterator(new StringReader(jsonData));
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    Int64Value.Builder builder = Int64Value.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[0]);
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    builder = Int64Value.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[1]);
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    builder = Int64Value.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[2]);
-
-    Truth.assertThat(streamIter.hasNext()).isFalse();
-
-    streamIter.close();
-  }
-
-  @Test
-  public void testMultipleElements() throws IOException {
-    Field[] expectedData =
-        new Field[] {
-          Field.newBuilder()
-              .setName("cat")
-              .addOptions(Option.newBuilder().setName("haha").build())
-              .addOptions(Option.newBuilder().setName("hoho").build())
-              .setNumber(1)
-              .setDefaultValue("mew")
-              .build(),
-          Field.newBuilder()
-              .setName("dog")
-              .addOptions(Option.newBuilder().setName("muu").build())
-              .setNumber(2)
-              .setDefaultValue("woof")
-              .build(),
-          Field.newBuilder()
-              .setName("cow")
-              .addOptions(Option.newBuilder().setName("bee").build())
-              .setNumber(3)
-              .setDefaultValue("muu")
-              .build()
-        };
-
-    String jsonData =
-        "[{\n"
-            + "  \"number\": 1,\n"
-            + "  \"name\": \"cat\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"haha\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"hoho\"\n"
-            + "  }],\n"
-            + "  \"defaultValue\": \"mew\"\n"
-            + "},\n"
-            + "{\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"dog\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"muu\"\n"
-            + "  }],\n"
-            + "  \"defaultValue\": \"woof\"\n"
-            + "},\n"
-            + "{\n"
-            + "  \"number\": 3,\n"
-            + "  \"name\": \"cow\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"bee\"\n"
-            + "  }],\n"
-            + "  \"defaultValue\": \"muu\"\n"
-            + "}]";
-
-    ProtoMessageJsonStreamIterator streamIter =
-        new ProtoMessageJsonStreamIterator(new StringReader(jsonData));
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    Field.Builder builder = Field.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[0]);
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    builder = Field.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[1]);
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    builder = Field.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData[2]);
-
-    Truth.assertThat(streamIter.hasNext()).isFalse();
-
-    streamIter.close();
-  }
-
-  @Test
-  public void testEscapedString() throws IOException {
-    Field expectedData =
-        Field.newBuilder()
-            .setName(
-                "[{\n"
-                    + "\"fInt32\": 23,\n"
-                    + "\"fInt64\": \"1234567889999977\",\n"
-                    + "\"fDouble\": 1234.343232226,\n"
-                    + "\"fKingdom\": \"ARCHAEBACTERIA\"\n"
-                    + "}]")
-            .build();
-
-    String jsonData =
-        "[{\n"
-            + "  \"name\": \"[{\\n"
-            + "\\\"fInt32\\\": 23,\\n"
-            + "\\\"fInt64\\\": \\\"1234567889999977\\\",\\n"
-            + "\\\"fDouble\\\": 1234.343232226,\\n"
-            + "\\\"fKingdom\\\": \\\"ARCHAEBACTERIA\\\"\\n"
-            + "}]\"\n"
-            + "}]";
-
-    ProtoMessageJsonStreamIterator streamIter =
-        new ProtoMessageJsonStreamIterator(new StringReader(jsonData));
-
-    Truth.assertThat(streamIter.hasNext()).isTrue();
-    Field.Builder builder = Field.newBuilder();
-    JsonFormat.parser().merge(streamIter.next(), builder);
-    Truth.assertThat(builder.build()).isEqualTo(expectedData);
-    Truth.assertThat(streamIter.hasNext()).isFalse();
-
-    streamIter.close();
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatterTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatterTest.java
deleted file mode 100644
index 8f43231c1..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageRequestFormatterTest.java
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.protobuf.Field.Cardinality;
-import com.google.protobuf.Option;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import org.junit.Before;
-import org.junit.Test;
-
-public class ProtoMessageRequestFormatterTest {
-  private Field field;
-  private ProtoMessageRequestFormatter<Field> formatter;
-
-  @Before
-  public void setUp() {
-    field =
-        Field.newBuilder()
-            .setNumber(2)
-            .setName("field_name1")
-            .addOptions(Option.newBuilder().setName("opt_name1").build())
-            .addOptions(Option.newBuilder().setName("opt_name2").build())
-            .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
-            .build();
-
-    formatter =
-        ProtoMessageRequestFormatter.<Field>newBuilder()
-            .setPath(
-                "/api/v1/names/{name=field_name1/**}/aggregated",
-                request -> {
-                  Map<String, String> fields = new HashMap<>();
-                  ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                  serializer.putPathParam(fields, "name", request.getName());
-                  serializer.putPathParam(fields, "kindValue", request.getKindValue());
-                  return fields;
-                })
-            .setQueryParamsExtractor(
-                request -> {
-                  Map<String, List<String>> fields = new HashMap<>();
-                  ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                  serializer.putQueryParam(fields, "number", request.getNumber());
-                  serializer.putQueryParam(fields, "typeUrl", request.getTypeUrl());
-                  return fields;
-                })
-            .setRequestBodyExtractor(
-                request -> {
-                  ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
-                  return serializer.toBody("field", request, false);
-                })
-            .setAdditionalPaths("/api/v1/names/{name=field_name1/**}/hello")
-            .build();
-  }
-
-  @Test
-  public void getQueryParamNames() {
-    Map<String, List<String>> queryParamNames = formatter.getQueryParamNames(field);
-    Map<String, List<String>> expected = new HashMap<>();
-    expected.put("number", Arrays.asList("2"));
-    expected.put("typeUrl", Arrays.asList(""));
-    Truth.assertThat(queryParamNames).isEqualTo(expected);
-
-    // Test toBuilder() case
-    queryParamNames = formatter.toBuilder().build().getQueryParamNames(field);
-    expected.put("number", Arrays.asList("2"));
-    expected.put("typeUrl", Arrays.asList(""));
-    Truth.assertThat(queryParamNames).isEqualTo(expected);
-  }
-
-  @Test
-  public void getRequestBody() {
-    String bodyJson = formatter.getRequestBody(field);
-    String expectedBodyJson =
-        "{\n"
-            + "  \"cardinality\": \"CARDINALITY_OPTIONAL\",\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"field_name1\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"opt_name1\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"opt_name2\"\n"
-            + "  }]\n"
-            + "}";
-    Truth.assertThat(bodyJson).isEqualTo(expectedBodyJson);
-
-    // Test toBuilder() case
-    formatter.toBuilder().build().getRequestBody(field);
-    Truth.assertThat(bodyJson).isEqualTo(expectedBodyJson);
-  }
-
-  @Test
-  public void getPath() {
-    String path = formatter.getPath(field);
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/aggregated");
-
-    // Test toBuilder() case
-    path = formatter.toBuilder().build().getPath(field);
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/aggregated");
-  }
-
-  @Test
-  public void getPathTemplate() {
-    String path =
-        formatter.getPathTemplate().instantiate(Collections.singletonMap("name", "field_name1"));
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/aggregated");
-
-    // Test toBuilder() case
-    path =
-        formatter
-            .toBuilder()
-            .build()
-            .getPathTemplate()
-            .instantiate(Collections.singletonMap("name", "field_name1"));
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/aggregated");
-  }
-
-  @Test
-  public void getPathTemplates() {
-    String path =
-        formatter
-            .getAdditionalPathTemplates()
-            .get(0)
-            .instantiate(Collections.singletonMap("name", "field_name1"));
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/hello");
-
-    // Test toBuilder() case
-    path =
-        formatter
-            .toBuilder()
-            .build()
-            .getAdditionalPathTemplates()
-            .get(0)
-            .instantiate(Collections.singletonMap("name", "field_name1"));
-    Truth.assertThat(path).isEqualTo("api/v1/names/field_name1/hello");
-  }
-
-  @Test
-  public void updateRawPath() {
-    String path = formatter.toBuilder().updateRawPath("/v1/", "/v1beta1/").build().getPath(field);
-    Truth.assertThat(path).isEqualTo("api/v1beta1/names/field_name1/aggregated");
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageResponseParserTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageResponseParserTest.java
deleted file mode 100644
index 86a01e676..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoMessageResponseParserTest.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import com.google.common.truth.Truth;
-import com.google.protobuf.Field;
-import com.google.protobuf.Field.Cardinality;
-import com.google.protobuf.Option;
-import com.google.protobuf.TypeRegistry;
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class ProtoMessageResponseParserTest {
-  private ProtoMessageResponseParser<Field> parser;
-  private Field field;
-  private String fieldJson;
-
-  @Before
-  public void setUp() {
-    parser =
-        ProtoMessageResponseParser.<Field>newBuilder()
-            .setDefaultInstance(Field.getDefaultInstance())
-            .build();
-
-    field =
-        Field.newBuilder()
-            .setNumber(2)
-            .setName("field_name1")
-            .addOptions(Option.newBuilder().setName("opt_name1").build())
-            .addOptions(Option.newBuilder().setName("opt_name2").build())
-            .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
-            .build();
-
-    fieldJson =
-        "{\n"
-            + "  \"cardinality\": \"CARDINALITY_OPTIONAL\",\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"field_name1\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"opt_name1\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"opt_name2\"\n"
-            + "  }]\n"
-            + "}";
-  }
-
-  @Test
-  public void parse() {
-    Field actualField =
-        parser.parse(new ByteArrayInputStream(fieldJson.getBytes(StandardCharsets.UTF_8)));
-    Truth.assertThat(actualField).isEqualTo(field);
-  }
-
-  @Test
-  public void parseWithTypeRegistry() {
-    Field actualField =
-        parser.parse(
-            new ByteArrayInputStream(fieldJson.getBytes(StandardCharsets.UTF_8)),
-            TypeRegistry.newBuilder().build());
-    Truth.assertThat(actualField).isEqualTo(field);
-  }
-
-  @Test
-  public void parseInvalidJson() {
-    try {
-      parser.parse(new ByteArrayInputStream("invalid".getBytes(StandardCharsets.UTF_8)));
-      Assert.fail();
-    } catch (RestSerializationException e) {
-      Truth.assertThat(e.getCause()).isInstanceOf(IOException.class);
-    }
-  }
-
-  @Test
-  public void serialize() {
-    String actualFieldJson = parser.serialize(field);
-    Truth.assertThat(actualFieldJson).isEqualTo(fieldJson);
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoOperationTransformersTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoOperationTransformersTest.java
deleted file mode 100644
index 38685f17b..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoOperationTransformersTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertThrows;
-
-import com.google.api.gax.httpjson.ProtoOperationTransformers.MetadataTransformer;
-import com.google.api.gax.httpjson.ProtoOperationTransformers.ResponseTransformer;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.UnavailableException;
-import com.google.api.gax.rpc.UnknownException;
-import com.google.common.truth.Truth;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Any;
-import com.google.rpc.Code;
-import com.google.rpc.Status;
-import com.google.type.Color;
-import com.google.type.Money;
-import org.junit.Test;
-
-public class ProtoOperationTransformersTest {
-
-  @Test
-  public void testResponseTransformer() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("UAH").build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("Madrid")
-            .setMetadata(2)
-            .setDone(true)
-            .setResponse(inputMoney)
-            .setError(0, "no error")
-            .build();
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testMetadataTransformer() {
-    MetadataTransformer<Money> transformer = MetadataTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("UAH").build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.newBuilder()
-            .setName("Barcelona")
-            .setMetadata(inputMoney)
-            .setDone(true)
-            .setResponse("Gary")
-            .setError(0, "no error")
-            .build();
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testAnyResponseTransformer() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.create(
-            Operation.newBuilder().setResponse(Any.pack(inputMoney)).build());
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testAnyResponseTransformer_exception() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    Status status = Status.newBuilder().setCode(Code.UNAVAILABLE.getNumber()).build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.create(
-            Operation.newBuilder().setResponse(Any.pack(inputMoney)).setError(status).build());
-
-    Exception exception =
-        assertThrows(UnavailableException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception)
-        .hasMessageThat()
-        .contains("failed with status = HttpJsonStatusCode{statusCode=UNAVAILABLE}");
-  }
-
-  @Test
-  public void testAnyResponseTransformer_mismatchedTypes() {
-    ResponseTransformer<Money> transformer = ResponseTransformer.create(Money.class);
-    Status status = Status.newBuilder().setCode(Code.OK.getNumber()).build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.create(
-            Operation.newBuilder()
-                .setResponse(Any.pack(Color.getDefaultInstance()))
-                .setError(status)
-                .build());
-    Exception exception =
-        assertThrows(UnknownException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception).hasMessageThat().contains("encountered a problem unpacking it");
-  }
-
-  @Test
-  public void testAnyMetadataTransformer() {
-    MetadataTransformer<Money> transformer = MetadataTransformer.create(Money.class);
-    Money inputMoney = Money.newBuilder().setCurrencyCode("USD").build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.create(
-            Operation.newBuilder().setMetadata(Any.pack(inputMoney)).build());
-    Truth.assertThat(transformer.apply(operationSnapshot)).isEqualTo(inputMoney);
-  }
-
-  @Test
-  public void testAnyMetadataTransformer_mismatchedTypes() {
-    MetadataTransformer<Money> transformer = MetadataTransformer.create(Money.class);
-    Status status = Status.newBuilder().setCode(Code.OK.getNumber()).build();
-    OperationSnapshot operationSnapshot =
-        HttpJsonOperationSnapshot.create(
-            Operation.newBuilder()
-                .setMetadata(Any.pack(Color.getDefaultInstance()))
-                .setError(status)
-                .build());
-    Exception exception =
-        assertThrows(UnknownException.class, () -> transformer.apply(operationSnapshot));
-    Truth.assertThat(exception).hasMessageThat().contains("encountered a problem unpacking it");
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoRestSerializerTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoRestSerializerTest.java
deleted file mode 100644
index 3ff9ceaf6..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/ProtoRestSerializerTest.java
+++ /dev/null
@@ -1,281 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.httpjson;
-
-import com.google.common.truth.Truth;
-import com.google.protobuf.Duration;
-import com.google.protobuf.Field;
-import com.google.protobuf.Field.Cardinality;
-import com.google.protobuf.FieldMask;
-import com.google.protobuf.FloatValue;
-import com.google.protobuf.Int32Value;
-import com.google.protobuf.Option;
-import com.google.protobuf.Timestamp;
-import com.google.protobuf.TypeRegistry;
-import com.google.rpc.RetryInfo;
-import com.google.type.Interval;
-import java.io.IOException;
-import java.io.StringReader;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class ProtoRestSerializerTest {
-  private ProtoRestSerializer<Field> requestSerializer;
-  private Field field;
-  private String fieldJson;
-  private String fieldJsonNumericEnum;
-  private String fieldJsonUnknownNumericEnum;
-
-  @Before
-  public void setUp() {
-    // tests with Any type messages require corresponding descriptors in the type registry
-    requestSerializer =
-        ProtoRestSerializer.create(
-            TypeRegistry.newBuilder()
-                .add(FieldMask.getDescriptor())
-                .add(Duration.getDescriptor())
-                .build());
-
-    field =
-        Field.newBuilder()
-            .setNumber(2)
-            .setName("field_name1")
-            .addOptions(Option.newBuilder().setName("opt_name1").build())
-            .addOptions(Option.newBuilder().setName("opt_name2").build())
-            .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
-            .build();
-
-    fieldJson =
-        "{\n"
-            + "  \"cardinality\": \"CARDINALITY_OPTIONAL\",\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"field_name1\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"opt_name1\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"opt_name2\"\n"
-            + "  }]\n"
-            + "}";
-
-    fieldJsonNumericEnum =
-        "{\n"
-            + "  \"cardinality\": 1,\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"field_name1\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"opt_name1\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"opt_name2\"\n"
-            + "  }]\n"
-            + "}";
-
-    fieldJsonUnknownNumericEnum =
-        "{\n"
-            + "  \"cardinality\": 7,\n"
-            + "  \"number\": 2,\n"
-            + "  \"name\": \"field_name1\",\n"
-            + "  \"options\": [{\n"
-            + "    \"name\": \"opt_name1\"\n"
-            + "  }, {\n"
-            + "    \"name\": \"opt_name2\"\n"
-            + "  }]\n"
-            + "}";
-  }
-
-  @Test
-  public void toJson_numericEnumTrue() {
-    String fieldToJson = requestSerializer.toJson(field, true);
-    Truth.assertThat(fieldToJson).isEqualTo(fieldJsonNumericEnum);
-  }
-
-  @Test
-  public void toJson_numericEnumFalse() {
-    String fieldToJson = requestSerializer.toJson(field, false);
-    Truth.assertThat(fieldToJson).isEqualTo(fieldJson);
-  }
-
-  @Test
-  public void fromJson_numericEnumTrue() {
-    Field fieldFromJson =
-        requestSerializer.fromJson(new StringReader(fieldJsonNumericEnum), Field.newBuilder());
-    Truth.assertThat(fieldFromJson).isEqualTo(field);
-  }
-
-  @Test
-  public void fromJson_numericEnumFalse() {
-    Field fieldFromJson =
-        requestSerializer.fromJson(new StringReader(fieldJson), Field.newBuilder());
-    Truth.assertThat(fieldFromJson).isEqualTo(field);
-  }
-
-  @Test
-  public void fromJson_numericEnumTrueAndUnknownEnum() {
-    Field expected = field.toBuilder().setCardinalityValue(7).build();
-    Field fieldFromJson =
-        requestSerializer.fromJson(
-            new StringReader(fieldJsonUnknownNumericEnum), Field.newBuilder());
-    Truth.assertThat(fieldFromJson).isEqualTo(expected);
-  }
-
-  @Test
-  public void fromJsonInvalidJson() {
-    try {
-      requestSerializer.fromJson(new StringReader("heh"), Field.newBuilder());
-      Assert.fail();
-    } catch (RestSerializationException e) {
-      Truth.assertThat(e.getCause()).isInstanceOf(IOException.class);
-    }
-  }
-
-  @Test
-  public void putPathParam() {
-    Map<String, String> fields = new HashMap<>();
-    requestSerializer.putPathParam(fields, "optName1", 1);
-    requestSerializer.putPathParam(fields, "optName2", 0);
-    requestSerializer.putPathParam(fields, "optName3", "three");
-    requestSerializer.putPathParam(fields, "optName4", "");
-
-    Map<String, String> expectedFields = new HashMap<>();
-    expectedFields.put("optName1", "1");
-    expectedFields.put("optName2", "0");
-    expectedFields.put("optName3", "three");
-    expectedFields.put("optName4", "");
-
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void putQueryParamPrimitive() {
-    Map<String, List<String>> fields = new HashMap<>();
-    requestSerializer.putQueryParam(fields, "optName1", 1);
-    requestSerializer.putQueryParam(fields, "optName2", 0);
-    requestSerializer.putQueryParam(fields, "optName3", "three");
-    requestSerializer.putQueryParam(fields, "optName4", "");
-    requestSerializer.putQueryParam(fields, "optName5", Arrays.asList("four", "five"));
-
-    Map<String, List<String>> expectedFields = new HashMap<>();
-    expectedFields.put("optName1", Arrays.asList("1"));
-    expectedFields.put("optName2", Arrays.asList("0"));
-    expectedFields.put("optName3", Arrays.asList("three"));
-    expectedFields.put("optName4", Arrays.asList(""));
-    expectedFields.put("optName5", Arrays.asList("four", "five"));
-
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void putQueryParamComplexObject() {
-    Map<String, List<String>> fields = new HashMap<>();
-    requestSerializer.putQueryParam(fields, "object", field);
-
-    Map<String, List<String>> expectedFields = new HashMap<>();
-    expectedFields.put("object.cardinality", Arrays.asList("1"));
-    expectedFields.put("object.name", Arrays.asList("field_name1"));
-    expectedFields.put("object.number", Arrays.asList("2"));
-    expectedFields.put("object.options.name", Arrays.asList("opt_name1", "opt_name2"));
-
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void putQueryParamComplexObjectDuration() {
-    Map<String, List<String>> fields = new HashMap<>();
-    Duration duration = Duration.newBuilder().setSeconds(1).setNanos(1).build();
-    RetryInfo input = RetryInfo.newBuilder().setRetryDelay(duration).build();
-    requestSerializer.putQueryParam(fields, "retry_info", input);
-
-    Map<String, List<String>> expectedFields = new HashMap<>();
-    expectedFields.put("retry_info.retryDelay", Arrays.asList("1.000000001s"));
-
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void putQueryParamComplexObjectTimestamp() {
-    Map<String, List<String>> fields = new HashMap<>();
-    Timestamp start = Timestamp.newBuilder().setSeconds(1).setNanos(1).build();
-    Timestamp end = Timestamp.newBuilder().setSeconds(2).setNanos(2).build();
-    Interval input = Interval.newBuilder().setStartTime(start).setEndTime(end).build();
-
-    requestSerializer.putQueryParam(fields, "object", input);
-
-    Map<String, List<String>> expectedFields = new HashMap<>();
-    expectedFields.put("object.startTime", Arrays.asList("1970-01-01T00:00:01.000000001Z"));
-    expectedFields.put("object.endTime", Arrays.asList("1970-01-01T00:00:02.000000002Z"));
-
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void putQueryParamDuration() {
-    queryParamHelper(Duration.newBuilder().setSeconds(1).setNanos(1).build(), "1.000000001s");
-  }
-
-  @Test
-  public void putQueryParamTimestamp() {
-    queryParamHelper(
-        Timestamp.newBuilder().setSeconds(1).setNanos(1).build(), "1970-01-01T00:00:01.000000001Z");
-  }
-
-  @Test
-  public void putQueryParamFieldMask() {
-    queryParamHelper(FieldMask.newBuilder().addPaths("a.b").addPaths("c.d").build(), "a.b,c.d");
-  }
-
-  @Test
-  public void putQueryParamInt32Value() {
-    queryParamHelper(Int32Value.of(1), "1");
-  }
-
-  @Test
-  public void putQueryParamFloatValue() {
-    queryParamHelper(FloatValue.of(1.1f), "1.1");
-  }
-
-  private void queryParamHelper(Object value, String expected) {
-    Map<String, List<String>> fields = new HashMap<>();
-    requestSerializer.putQueryParam(fields, "value", value);
-    Map<String, List<String>> expectedFields = new HashMap<>();
-    expectedFields.put("value", Arrays.asList(expected));
-    Truth.assertThat(fields).isEqualTo(expectedFields);
-  }
-
-  @Test
-  public void toBody() {
-    String body = requestSerializer.toBody("bodyField1", field, false);
-    Truth.assertThat(body).isEqualTo(fieldJson);
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/RetryingTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/RetryingTest.java
deleted file mode 100644
index d03d7e57f..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/RetryingTest.java
+++ /dev/null
@@ -1,329 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson;
-
-import static org.junit.Assert.assertThrows;
-
-import com.google.api.client.http.HttpHeaders;
-import com.google.api.client.http.HttpResponseException;
-import com.google.api.client.http.HttpStatusCodes;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.core.RecordingScheduler;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.FailedPreconditionException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.UnknownException;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.truth.Truth;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.UncheckedExecutionException;
-import java.util.Set;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class RetryingTest {
-
-  @SuppressWarnings("unchecked")
-  private final UnaryCallable<Integer, Integer> callInt = Mockito.mock(UnaryCallable.class);
-
-  private RecordingScheduler executor;
-  private FakeApiClock fakeClock;
-  private ClientContext clientContext;
-
-  private static final int HTTP_CODE_PRECONDITION_FAILED = 412;
-
-  private HttpResponseException HTTP_SERVICE_UNAVAILABLE_EXCEPTION =
-      new HttpResponseException.Builder(
-              HttpStatusCodes.STATUS_CODE_SERVICE_UNAVAILABLE,
-              "server unavailable",
-              new HttpHeaders())
-          .build();
-
-  private static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(2L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(2L))
-          .setInitialRpcTimeout(Duration.ofMillis(2L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(2L))
-          .setTotalTimeout(Duration.ofMillis(10L))
-          .build();
-
-  @Before
-  public void resetClock() {
-    fakeClock = new FakeApiClock(System.nanoTime());
-    executor = RecordingScheduler.create(fakeClock);
-    clientContext =
-        ClientContext.newBuilder()
-            .setExecutor(executor)
-            .setClock(fakeClock)
-            .setDefaultCallContext(HttpJsonCallContext.createDefault())
-            .build();
-  }
-
-  @After
-  public void teardown() {
-    executor.shutdownNow();
-  }
-
-  @Test
-  public void retry() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    UnaryCallSettings<Integer, Integer> callSettings =
-        createSettings(retryable, FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    Truth.assertThat(callable.call(1)).isEqualTo(2);
-  }
-
-  @Test
-  public void retryTotalTimeoutExceeded() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    HttpResponseException httpResponseException =
-        new HttpResponseException.Builder(
-                HttpStatusCodes.STATUS_CODE_SERVICE_UNAVAILABLE,
-                "server unavailable",
-                new HttpHeaders())
-            .build();
-    ApiException apiException =
-        ApiExceptionFactory.createException(
-            "foobar",
-            httpResponseException,
-            HttpJsonStatusCode.of(Code.FAILED_PRECONDITION),
-            false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(apiException))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .setMaxRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .build();
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(retryable, retrySettings);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    assertThrows(ApiException.class, () -> callable.call(1));
-  }
-
-  @Test
-  public void retryMaxAttemptsExceeded() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    RetrySettings retrySettings = FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(2).build();
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(retryable, retrySettings);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    assertThrows(ApiException.class, () -> callable.call(1));
-  }
-
-  @Test
-  public void retryWithinMaxAttempts() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(HTTP_SERVICE_UNAVAILABLE_EXCEPTION))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    RetrySettings retrySettings = FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(3).build();
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(retryable, retrySettings);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    callable.call(1);
-    Truth.assertThat(callable.call(1)).isEqualTo(2);
-  }
-
-  @Test
-  public void retryOnStatusUnknown() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNKNOWN);
-    HttpResponseException throwable =
-        new HttpResponseException.Builder(
-                HttpStatusCodes.STATUS_CODE_TEMPORARY_REDIRECT,
-                "temporary redirect",
-                new HttpHeaders())
-            .build();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        createSettings(retryable, FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    Truth.assertThat(callable.call(1)).isEqualTo(2);
-  }
-
-  @Test
-  public void retryOnUnexpectedException() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNKNOWN);
-    Throwable throwable = new RuntimeException("foobar");
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        createSettings(retryable, FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    ApiException exception = assertThrows(ApiException.class, () -> callable.call(1));
-    Truth.assertThat(exception).hasCauseThat().isSameInstanceAs(throwable);
-  }
-
-  @Test
-  public void retryNoRecover() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    HttpResponseException httpResponseException =
-        new HttpResponseException.Builder(
-                HTTP_CODE_PRECONDITION_FAILED, "foobar", new HttpHeaders())
-            .build();
-    ApiException apiException =
-        ApiExceptionFactory.createException(
-            "foobar",
-            httpResponseException,
-            HttpJsonStatusCode.of(Code.FAILED_PRECONDITION),
-            false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(apiException))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        createSettings(retryable, FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    ApiException exception = assertThrows(ApiException.class, () -> callable.call(1));
-    Truth.assertThat(exception).isSameInstanceAs(apiException);
-  }
-
-  @Test
-  public void retryKeepFailing() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    HttpResponseException throwable =
-        new HttpResponseException.Builder(
-                HttpStatusCodes.STATUS_CODE_SERVICE_UNAVAILABLE, "Unavailable", new HttpHeaders())
-            .build();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        createSettings(retryable, FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    // Need to advance time inside the call.
-    ApiFuture<Integer> future = callable.futureCall(1);
-
-    UncheckedExecutionException exception =
-        assertThrows(UncheckedExecutionException.class, () -> Futures.getUnchecked(future));
-    Truth.assertThat(exception).hasCauseThat().isInstanceOf(ApiException.class);
-    Truth.assertThat(exception).hasCauseThat().hasMessageThat().contains("Unavailable");
-  }
-
-  @Test
-  public void testKnownStatusCode() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(Code.UNAVAILABLE);
-    String throwableMessage =
-        "{\n"
-            + " \"error\": {\n"
-            + "  \"errors\": [\n"
-            + "   {\n"
-            + "    \"domain\": \"global\",\n"
-            + "    \"reason\": \"FAILED_PRECONDITION\",\n"
-            + "   }\n"
-            + "  ],\n"
-            + "  \"code\": 400,\n"
-            + "  \"message\": \"Failed precondition.\"\n"
-            + " }\n"
-            + "}";
-    HttpResponseException throwable =
-        new HttpResponseException.Builder(
-                HTTP_CODE_PRECONDITION_FAILED, "precondition failed", new HttpHeaders())
-            .setMessage(throwableMessage)
-            .build();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(throwable));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(retryable)
-            .build();
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    ApiException exception =
-        assertThrows(FailedPreconditionException.class, () -> callable.call(1));
-    Truth.assertThat(exception.getStatusCode().getTransportCode())
-        .isEqualTo(HTTP_CODE_PRECONDITION_FAILED);
-    Truth.assertThat(exception).hasMessageThat().contains("precondition failed");
-  }
-
-  @Test
-  public void testUnknownStatusCode() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.<Integer>immediateFailedFuture(new RuntimeException("unknown")));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(retryable)
-            .build();
-    UnaryCallable<Integer, Integer> callable =
-        HttpJsonCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    UnknownException exception = assertThrows(UnknownException.class, () -> callable.call(1));
-    Truth.assertThat(exception).hasMessageThat().isEqualTo("java.lang.RuntimeException: unknown");
-  }
-
-  public static UnaryCallSettings<Integer, Integer> createSettings(
-      Set<StatusCode.Code> retryableCodes, RetrySettings retrySettings) {
-    return UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-        .setRetryableCodes(retryableCodes)
-        .setRetrySettings(retrySettings)
-        .build();
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/longrunning/OperationsClientTest.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/longrunning/OperationsClientTest.java
deleted file mode 100644
index 1240ba742..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/longrunning/OperationsClientTest.java
+++ /dev/null
@@ -1,264 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.longrunning;
-
-import com.google.api.gax.core.NoCredentialsProvider;
-import com.google.api.gax.httpjson.GaxHttpJsonProperties;
-import com.google.api.gax.httpjson.longrunning.OperationsClient.ListOperationsPagedResponse;
-import com.google.api.gax.httpjson.longrunning.stub.HttpJsonOperationsStub;
-import com.google.api.gax.httpjson.testing.MockHttpService;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.collect.Lists;
-import com.google.longrunning.ListOperationsResponse;
-import com.google.longrunning.Operation;
-import com.google.protobuf.Any;
-import com.google.protobuf.Empty;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-
-public class OperationsClientTest {
-  private static MockHttpService mockService;
-  private static OperationsClient client;
-
-  @BeforeClass
-  public static void startStaticServer() throws IOException {
-    mockService =
-        new MockHttpService(
-            HttpJsonOperationsStub.getMethodDescriptors(), OperationsSettings.getDefaultEndpoint());
-    OperationsSettings settings =
-        OperationsSettings.newBuilder()
-            .setTransportChannelProvider(
-                OperationsSettings.defaultHttpJsonTransportProviderBuilder()
-                    .setHttpTransport(mockService)
-                    .build())
-            .setCredentialsProvider(NoCredentialsProvider.create())
-            .build();
-    client = OperationsClient.create(settings);
-  }
-
-  @AfterClass
-  public static void stopServer() {
-    client.close();
-  }
-
-  @After
-  public void tearDown() {
-    mockService.reset();
-  }
-
-  @Test
-  public void listOperationsTest() {
-    Operation responsesElement = Operation.newBuilder().build();
-    ListOperationsResponse expectedResponse =
-        ListOperationsResponse.newBuilder()
-            .setNextPageToken("")
-            .addAllOperations(Arrays.asList(responsesElement))
-            .build();
-    mockService.addResponse(expectedResponse);
-
-    String name = "operations";
-    String filter = "filter-1274492040";
-
-    ListOperationsPagedResponse pagedListResponse = client.listOperations(name, filter);
-
-    List<Operation> resources = Lists.newArrayList(pagedListResponse.iterateAll());
-
-    Assert.assertEquals(1, resources.size());
-    Assert.assertEquals(expectedResponse.getOperationsList().get(0), resources.get(0));
-
-    List<String> actualRequests = mockService.getRequestPaths();
-    Assert.assertEquals(1, actualRequests.size());
-
-    String apiClientHeaderKey =
-        mockService
-            .getRequestHeaders()
-            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
-            .iterator()
-            .next();
-    Assert.assertTrue(
-        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
-            .matcher(apiClientHeaderKey)
-            .matches());
-  }
-
-  @Test
-  public void listOperationsExceptionTest() {
-    ApiException exception =
-        ApiExceptionFactory.createException(
-            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
-    mockService.addException(exception);
-
-    try {
-      String name = "operations";
-      String filter = "filter-1274492040";
-      client.listOperations(name, filter);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception.
-    }
-  }
-
-  @Test
-  public void getOperationTest() {
-    Operation expectedResponse =
-        Operation.newBuilder()
-            .setName("operations/hey1")
-            .setMetadata(Any.newBuilder().build())
-            .setDone(true)
-            .build();
-    mockService.addResponse(expectedResponse);
-
-    String name = "operations/3373707";
-
-    Operation actualResponse = client.getOperation(name);
-    Assert.assertEquals(expectedResponse, actualResponse);
-
-    List<String> actualRequests = mockService.getRequestPaths();
-    Assert.assertEquals(1, actualRequests.size());
-
-    String apiClientHeaderKey =
-        mockService
-            .getRequestHeaders()
-            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
-            .iterator()
-            .next();
-    Assert.assertTrue(
-        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
-            .matcher(apiClientHeaderKey)
-            .matches());
-  }
-
-  @Test
-  public void getOperationExceptionTest() {
-    ApiException exception =
-        ApiExceptionFactory.createException(
-            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
-    mockService.addException(exception);
-
-    try {
-      String name = "operations/3373707";
-      client.getOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception.
-    }
-  }
-
-  @Test
-  public void deleteOperationTest() {
-    Empty expectedResponse = Empty.newBuilder().build();
-    mockService.addResponse(expectedResponse);
-
-    String name = "operations/3373707";
-
-    client.deleteOperation(name);
-
-    List<String> actualRequests = mockService.getRequestPaths();
-    Assert.assertEquals(1, actualRequests.size());
-
-    String apiClientHeaderKey =
-        mockService
-            .getRequestHeaders()
-            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
-            .iterator()
-            .next();
-    Assert.assertTrue(
-        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
-            .matcher(apiClientHeaderKey)
-            .matches());
-  }
-
-  @Test
-  public void deleteOperationExceptionTest() {
-    ApiException exception =
-        ApiExceptionFactory.createException(
-            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
-    mockService.addException(exception);
-
-    try {
-      String name = "operations/3373707";
-      client.deleteOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception.
-    }
-  }
-
-  @Test
-  public void cancelOperationTest() {
-    Empty expectedResponse = Empty.newBuilder().build();
-    mockService.addResponse(expectedResponse);
-
-    String name = "operations/3373707";
-
-    client.cancelOperation(name);
-
-    List<String> actualRequests = mockService.getRequestPaths();
-    Assert.assertEquals(1, actualRequests.size());
-
-    String apiClientHeaderKey =
-        mockService
-            .getRequestHeaders()
-            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
-            .iterator()
-            .next();
-    Assert.assertTrue(
-        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
-            .matcher(apiClientHeaderKey)
-            .matches());
-  }
-
-  @Test
-  public void cancelOperationExceptionTest() {
-    ApiException exception =
-        ApiExceptionFactory.createException(
-            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
-    mockService.addException(exception);
-
-    try {
-      String name = "operations/3373707";
-      client.cancelOperation(name);
-      Assert.fail("No exception raised");
-    } catch (InvalidArgumentException e) {
-      // Expected exception.
-    }
-  }
-}
diff --git a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/testing/MockHttpService.java b/gax-httpjson/src/test/java/com/google/api/gax/httpjson/testing/MockHttpService.java
deleted file mode 100644
index b2ebee14d..000000000
--- a/gax-httpjson/src/test/java/com/google/api/gax/httpjson/testing/MockHttpService.java
+++ /dev/null
@@ -1,262 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.httpjson.testing;
-
-import com.google.api.client.http.HttpMethods;
-import com.google.api.client.http.LowLevelHttpRequest;
-import com.google.api.client.http.LowLevelHttpResponse;
-import com.google.api.client.testing.http.MockHttpTransport;
-import com.google.api.client.testing.http.MockLowLevelHttpRequest;
-import com.google.api.client.testing.http.MockLowLevelHttpResponse;
-import com.google.api.gax.httpjson.ApiMethodDescriptor;
-import com.google.api.gax.httpjson.ApiMethodDescriptor.MethodType;
-import com.google.api.pathtemplate.PathTemplate;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableListMultimap;
-import com.google.common.collect.LinkedListMultimap;
-import com.google.common.collect.Multimap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-/**
- * Mocks an HTTPTransport. Expected responses and exceptions can be added to a queue from which this
- * mock HttpTransport polls when it relays a response.
- *
- * <p>As required by {@link MockHttpTransport} this implementation is thread-safe, but it is not
- * idempotent (as a typical service would be) and must be used with extra caution. Mocked responses
- * are returned in FIFO order and if multiple threads read from the same MockHttpService
- * simultaneously, they may be getting responses intended for other consumers.
- */
-public final class MockHttpService extends MockHttpTransport {
-  private final Multimap<String, String> requestHeaders = LinkedListMultimap.create();
-  private final List<String> requestPaths = new LinkedList<>();
-  private final Queue<HttpResponseFactory> responseHandlers = new LinkedList<>();
-  private final List<ApiMethodDescriptor> serviceMethodDescriptors;
-  private final String endpoint;
-
-  /**
-   * Create a MockHttpService.
-   *
-   * @param serviceMethodDescriptors - list of method descriptors for the methods that this mock
-   *     server supports
-   * @param pathPrefix - the fixed portion of the endpoint URL that prefixes the methods' path
-   *     template substring.
-   */
-  public MockHttpService(List<ApiMethodDescriptor> serviceMethodDescriptors, String pathPrefix) {
-    this.serviceMethodDescriptors = ImmutableList.copyOf(serviceMethodDescriptors);
-    this.endpoint = pathPrefix;
-  }
-
-  @Override
-  public synchronized LowLevelHttpRequest buildRequest(String method, String url) {
-    requestPaths.add(url);
-    return new MockHttpRequest(this, method, url);
-  }
-
-  /** Add an ApiMessage to the response queue. */
-  public synchronized void addResponse(Object response) {
-    responseHandlers.add(new MessageResponseFactory(endpoint, serviceMethodDescriptors, response));
-  }
-
-  /** Add an expected null response (empty HTTP response body) with a custom status code. */
-  public synchronized void addNullResponse(int statusCode) {
-    responseHandlers.add(
-        (httpMethod, targetUrl) -> new MockLowLevelHttpResponse().setStatusCode(statusCode));
-  }
-
-  /** Add an expected null response (empty HTTP response body). */
-  public synchronized void addNullResponse() {
-    addNullResponse(200);
-  }
-
-  /** Add an Exception to the response queue. */
-  public synchronized void addException(Exception exception) {
-    addException(400, exception);
-  }
-
-  public synchronized void addException(int statusCode, Exception exception) {
-    responseHandlers.add(new ExceptionResponseFactory(statusCode, exception));
-  }
-
-  /** Get the FIFO list of URL paths to which requests were sent. */
-  public synchronized List<String> getRequestPaths() {
-    return requestPaths;
-  }
-
-  /** Get the FIFO list of request headers sent. */
-  public synchronized Multimap<String, String> getRequestHeaders() {
-    return ImmutableListMultimap.copyOf(requestHeaders);
-  }
-
-  private synchronized void putRequestHeader(String name, String value) {
-    requestHeaders.put(name, value);
-  }
-
-  private synchronized MockLowLevelHttpResponse getHttpResponse(String method, String url) {
-    Preconditions.checkArgument(!responseHandlers.isEmpty());
-    return responseHandlers.poll().getHttpResponse(method, url);
-  }
-
-  /* Reset the expected response queue, the method descriptor, and the logged request paths list. */
-  public synchronized void reset() {
-    responseHandlers.clear();
-    requestPaths.clear();
-    requestHeaders.clear();
-  }
-
-  private interface HttpResponseFactory {
-    MockLowLevelHttpResponse getHttpResponse(String httpMethod, String targetUrl);
-  }
-
-  private static class MockHttpRequest extends MockLowLevelHttpRequest {
-    private final MockHttpService service;
-    private final String method;
-    private final String url;
-
-    public MockHttpRequest(MockHttpService service, String method, String url) {
-      this.service = service;
-      this.method = method;
-      this.url = url;
-    }
-
-    @Override
-    public void addHeader(String name, String value) {
-      service.putRequestHeader(name, value);
-    }
-
-    @Override
-    public LowLevelHttpResponse execute() {
-      return service.getHttpResponse(method, url);
-    }
-  }
-
-  private static class ExceptionResponseFactory implements HttpResponseFactory {
-    private final int statusCode;
-    private final Exception exception;
-
-    public ExceptionResponseFactory(int statusCode, Exception exception) {
-      this.statusCode = statusCode;
-      this.exception = exception;
-    }
-
-    @Override
-    public MockLowLevelHttpResponse getHttpResponse(String httpMethod, String targetUrl) {
-      MockLowLevelHttpResponse httpResponse = new MockLowLevelHttpResponse();
-      httpResponse.setStatusCode(statusCode);
-      httpResponse.setContent(exception.toString().getBytes());
-      httpResponse.setContentEncoding("text/plain");
-      return httpResponse;
-    }
-  }
-
-  private static class MessageResponseFactory implements HttpResponseFactory {
-    private final List<ApiMethodDescriptor> serviceMethodDescriptors;
-    private final Object response;
-    private final String endpoint;
-
-    public MessageResponseFactory(
-        String endpoint, List<ApiMethodDescriptor> serviceMethodDescriptors, Object response) {
-      this.endpoint = endpoint;
-      this.serviceMethodDescriptors = ImmutableList.copyOf(serviceMethodDescriptors);
-      this.response = response;
-    }
-
-    @Override
-    public MockLowLevelHttpResponse getHttpResponse(String httpMethod, String fullTargetUrl) {
-      MockLowLevelHttpResponse httpResponse = new MockLowLevelHttpResponse();
-
-      String relativePath = getRelativePath(fullTargetUrl);
-
-      for (ApiMethodDescriptor methodDescriptor : serviceMethodDescriptors) {
-        // Check the comment in com.google.api.gax.httpjson.HttpRequestRunnable.buildRequest()
-        // method for details why it is needed.
-        String descriptorHttpMethod = methodDescriptor.getHttpMethod();
-        if (!httpMethod.equals(descriptorHttpMethod)) {
-          if (!(HttpMethods.PATCH.equals(descriptorHttpMethod)
-              && HttpMethods.POST.equals(httpMethod))) {
-            continue;
-          }
-        }
-
-        PathTemplate pathTemplate = methodDescriptor.getRequestFormatter().getPathTemplate();
-        List<PathTemplate> additionalPathTemplates =
-            methodDescriptor.getRequestFormatter().getAdditionalPathTemplates();
-        // Server figures out which RPC method is called based on the endpoint path pattern(s).
-        if (!pathTemplate.matches(relativePath)
-            && additionalPathTemplates.stream().noneMatch(pt -> pt.matches(relativePath))) {
-          continue;
-        }
-
-        // Emulate the server's creation of an HttpResponse from the response message
-        // instance.
-        String httpContent;
-        if (methodDescriptor.getType() == MethodType.SERVER_STREAMING) {
-          // Quick and dirty json array construction. Good enough for
-          Object[] responseArray = (Object[]) response;
-          StringBuilder sb = new StringBuilder();
-          sb.append('[');
-          for (Object responseElement : responseArray) {
-            if (sb.length() > 1) {
-              sb.append(',');
-            }
-            sb.append(methodDescriptor.getResponseParser().serialize(responseElement));
-          }
-          sb.append(']');
-          httpContent = sb.toString();
-        } else {
-          httpContent = methodDescriptor.getResponseParser().serialize(response);
-        }
-
-        httpResponse.setContent(httpContent.getBytes());
-        httpResponse.setStatusCode(200);
-        return httpResponse;
-      }
-
-      // Return 404 when none of this server's endpoint templates match the given URL.
-      httpResponse.setContent(
-          String.format("Method not found for path '%s'", relativePath).getBytes());
-      httpResponse.setStatusCode(404);
-      return httpResponse;
-    }
-
-    private String getRelativePath(String fullTargetUrl) {
-      // relativePath will be repeatedly truncated until it contains only
-      // the path template substring of the endpoint URL.
-      String relativePath = fullTargetUrl.replaceFirst(endpoint, "");
-      int queryParamIndex = relativePath.indexOf("?");
-      queryParamIndex = queryParamIndex < 0 ? relativePath.length() : queryParamIndex;
-      relativePath = relativePath.substring(0, queryParamIndex);
-
-      return relativePath;
-    }
-  }
-}
diff --git a/gax/BUILD.bazel b/gax/BUILD.bazel
deleted file mode 100644
index 0152f2503..000000000
--- a/gax/BUILD.bazel
+++ /dev/null
@@ -1,86 +0,0 @@
-load("//:gax_java.bzl", "google_java_format", "google_java_format_verification", "java_tests")
-
-_JAVA_COPTS = [
-    "-source",
-    "1.8",
-    "-target",
-    "1.8",
-]
-
-_COMPILE_DEPS = [
-    "@com_google_api_api_common//jar",
-    "@com_google_api_grpc_proto_google_common_protos//jar",
-    "@com_google_protobuf_java//jar",
-    "@com_google_auth_google_auth_library_credentials//jar",
-    "@com_google_auth_google_auth_library_oauth2_http//jar",
-    "@com_google_auto_value_auto_value//jar",
-    "@com_google_auto_value_auto_value_annotations//jar",
-    "@com_google_code_findbugs_jsr305//jar",
-    "@com_google_guava_guava//jar",
-    "@io_opencensus_opencensus_api//jar",
-    "@io_opencensus_opencensus_contrib_http_util//jar",
-    "@io_grpc_grpc_java//context:context",
-    "@org_threeten_threetenbp//jar",
-    "@com_google_http_client_google_http_client//jar",
-    "@com_google_http_client_google_http_client_gson//jar",
-    "@com_google_code_gson_gson//jar",
-    "@com_google_guava_failureaccess//jar",
-    "@javax_annotation_javax_annotation_api//jar",
-    "@org_graalvm_sdk//jar"
-]
-
-_TEST_COMPILE_DEPS = [
-    "@junit_junit//jar",
-    "@org_mockito_mockito_core//jar",
-    "@com_google_truth_truth//jar",
-    "@org_hamcrest_hamcrest_core//jar",
-    "@net_bytebuddy_byte_buddy//jar",
-    "@org_objenesis_objenesis//jar",
-    "@com_googlecode_java_diff_utils_diffutils//jar",
-]
-
-java_library(
-    name = "gax",
-    srcs = glob(["src/main/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    resources = ["//:dependencies.properties"],
-    visibility = ["//visibility:public"],
-    deps = _COMPILE_DEPS,
-)
-
-java_library(
-    name = "gax_testlib",
-    srcs = glob(["src/test/java/**/*.java"]),
-    javacopts = _JAVA_COPTS,
-    plugins = ["//:auto_value_plugin"],
-    resources = glob([
-        "src/test/resources/com/google/api/gax/rpc/mtls/mtls_context_aware_metadata.json",
-        "src/test/resources/com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem",
-    ]),
-    visibility = ["//visibility:public"],
-    deps = [":gax"] + _COMPILE_DEPS + _TEST_COMPILE_DEPS,
-)
-
-java_tests(
-    name = "gax_tests",
-    size = "small",
-    srcs = glob(
-        include = ["src/test/java/**/*Test.java"],
-        exclude = ["src/test/java/**/Abstract*Test.java"],
-    ),
-    runtime_deps = [":gax_testlib"],
-)
-
-google_java_format(
-    name = "google_java_format",
-    srcs = glob(["src/**/*.java"]),
-    formatter = "//:google_java_format_binary",
-)
-
-#Uncomment once java formatter is upgraded to 1.6+
-#google_java_format_verification(
-#    name = "google_java_format_verification",
-#    srcs = glob(["src/**/*.java"]),
-#    formatter = "//:google_java_format_binary",
-#)
diff --git a/gax/build.gradle b/gax/build.gradle
deleted file mode 100644
index f92a8cf9f..000000000
--- a/gax/build.gradle
+++ /dev/null
@@ -1,47 +0,0 @@
-archivesBaseName = "gax"
-
-// TODO: Populate this from dependencies.properties version property (for proper Gradle-Bazel sync)
-project.version = "2.20.1" // {x-version-update:gax:current}
-
-dependencies {
-  api(libraries['maven.com_google_api_api_common'],
-          libraries['maven.com_google_api_grpc_proto_google_common_protos'],
-          libraries['maven.com_google_auth_google_auth_library_credentials'],
-    libraries['maven.org_threeten_threetenbp'])
-
-  implementation(libraries['maven.com_google_auth_google_auth_library_oauth2_http'],
-    libraries['maven.com_google_code_findbugs_jsr305'],
-    libraries['maven.com_google_guava_guava'],
-    libraries['maven.io_opencensus_opencensus_api'])
-
-  compileOnly(libraries['maven.com_google_auto_value_auto_value'],
-          libraries['maven.org_graalvm_sdk'])
-
-  testImplementation(libraries['maven.junit_junit'],
-    libraries['maven.org_mockito_mockito_core'],
-    libraries['maven.com_google_truth_truth'],
-    libraries['maven.com_google_auto_value_auto_value'],
-          libraries['maven.org_graalvm_sdk'])
-
-  annotationProcessor libraries['maven.com_google_auto_value_auto_value']
-  testAnnotationProcessor libraries['maven.com_google_auto_value_auto_value']
-
-  shadowNoGuava libraries['maven.com_google_guava_guava']
-}
-
-processResources {
-  filesMatching('dependencies.properties') {
-    expand('project': project)
-  }
-}
-
-jar {
-  manifest {
-    attributes 'Specification-Title': project.name,
-      'Specification-Version': project.version,
-      'Specification-Vendor': libraryVendor,
-      'Implementation-Title': project.name,
-      'Implementation-Version': project.version,
-      'Implementation-Vendor': libraryVendor
-  }
-}
diff --git a/gax/pom.xml b/gax/pom.xml
deleted file mode 100644
index 09f587cb3..000000000
--- a/gax/pom.xml
+++ /dev/null
@@ -1,86 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <artifactId>gax</artifactId>
-  <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-  <packaging>jar</packaging>
-  <name>GAX (Google Api eXtensions) for Java (Core)</name>
-  <description>Google Api eXtensions for Java (Core)</description>
-
-  <parent>
-    <groupId>com.google.api</groupId>
-    <artifactId>gax-parent</artifactId>
-    <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-  </parent>
-
-  <dependencies>
-    <dependency>
-      <groupId>com.google.api</groupId>
-      <artifactId>api-common</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-credentials</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.api.grpc</groupId>
-      <artifactId>proto-google-common-protos</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.protobuf</groupId>
-      <artifactId>protobuf-java</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>org.threeten</groupId>
-      <artifactId>threetenbp</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>io.opencensus</groupId>
-      <artifactId>opencensus-api</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.guava</groupId>
-      <artifactId>guava</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.auth</groupId>
-      <artifactId>google-auth-library-oauth2-http</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>com.google.code.findbugs</groupId>
-      <artifactId>jsr305</artifactId>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.graalvm.sdk</groupId>
-      <artifactId>graal-sdk</artifactId>
-      <scope>provided</scope>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <executions>
-          <execution>
-            <goals>
-              <goal>test-jar</goal>
-            </goals>
-            <configuration>
-              <skip>false</skip>
-              <classifier>testlib</classifier>
-              <includes>
-                <include>com/google/api/gax/core/**</include>
-                <include>com/google/api/gax/rpc/testing/**</include>
-                <include>com/google/api/gax/rpc/mtls/**</include>
-              </includes>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
-</project>
\ No newline at end of file
diff --git a/gax/src/main/java/com/google/api/gax/batching/AccumulatingBatchReceiver.java b/gax/src/main/java/com/google/api/gax/batching/AccumulatingBatchReceiver.java
deleted file mode 100644
index 3e6e47013..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/AccumulatingBatchReceiver.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.ApiFuture;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.ConcurrentLinkedQueue;
-
-/** A simple ThresholdBatchReceiver that just accumulates batches. */
-public final class AccumulatingBatchReceiver<T> implements ThresholdBatchReceiver<T> {
-  private final ConcurrentLinkedQueue<T> batches = new ConcurrentLinkedQueue<>();
-  private final ApiFuture<?> retFuture;
-
-  public AccumulatingBatchReceiver(ApiFuture<?> retFuture) {
-    this.retFuture = retFuture;
-  }
-
-  @Override
-  public void validateBatch(T message) {
-    // no-op
-  }
-
-  @Override
-  public ApiFuture<?> processBatch(T batch) {
-    batches.add(batch);
-    return retFuture;
-  }
-
-  /**
-   * Returns the accumulated batches. If called concurrently with {@code processBatch}, the new
-   * batch may or may not be returned.
-   */
-  public List<T> getBatches() {
-    return new ArrayList<>(batches);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchEntry.java b/gax/src/main/java/com/google/api/gax/batching/BatchEntry.java
deleted file mode 100644
index 163eae9fd..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchEntry.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-import com.google.api.core.SettableApiFuture;
-import com.google.auto.value.AutoValue;
-import javax.annotation.Nullable;
-
-/**
- * This class contains the element and its corresponding unresolved future, which would be resolved
- * when batch is {@link BatchingDescriptor#splitResponse successful} or {@link
- * BatchingDescriptor#splitException failed}.
- *
- * @param <ElementT> The type of each individual element to be batched.
- * @param <ElementResultT> The type of the result for each individual element.
- */
-@InternalApi("For google-cloud-java client use only.")
-@AutoValue
-public abstract class BatchEntry<ElementT, ElementResultT> {
-
-  /** Returns a new BatchEntry */
-  public static <ElementT, ElementResultT> BatchEntry<ElementT, ElementResultT> create(
-      @Nullable ElementT element, SettableApiFuture<ElementResultT> resultFuture) {
-    return new AutoValue_BatchEntry<>(element, resultFuture);
-  }
-
-  @Nullable
-  public abstract ElementT getElement();
-
-  public abstract SettableApiFuture<ElementResultT> getResultFuture();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchMerger.java b/gax/src/main/java/com/google/api/gax/batching/BatchMerger.java
deleted file mode 100644
index 2d8005307..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchMerger.java
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-public interface BatchMerger<B> {
-  void merge(B batch, B newBatch);
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/Batcher.java b/gax/src/main/java/com/google/api/gax/batching/Batcher.java
deleted file mode 100644
index 1e069d53e..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/Batcher.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.rpc.ApiCallContext;
-
-/**
- * Represents a batching context where individual elements will be accumulated and flushed in a
- * large batch request at some point in the future. The buffered elements can be flushed manually or
- * when triggered by an internal threshold. This is intended to be used for high throughput
- * scenarios at the cost of latency.
- *
- * <p>Batcher instances are not thread safe. To use across different threads, create a new Batcher
- * instance per thread.
- *
- * @param <ElementT> The type of each individual element to be batched.
- * @param <ElementResultT> The type of the result for each individual element.
- */
-@InternalExtensionOnly
-public interface Batcher<ElementT, ElementResultT> extends AutoCloseable {
-
-  /** {@link ApiCallContext.Key} for tracking batch total throttled time */
-  ApiCallContext.Key<Long> THROTTLED_TIME_KEY = ApiCallContext.Key.create("total_throttled_time");
-
-  /**
-   * Queues the passed in element to be sent at some point in the future.
-   *
-   * <p>The element will be sent as part of a larger batch request at some point in the future. The
-   * returned {@link ApiFuture} will be resolved once the result for the element has been extracted
-   * from the batch response.
-   *
-   * <p>Note: Cancelling returned result simply marks the future cancelled, It would not stop the
-   * batch request.
-   */
-  ApiFuture<ElementResultT> add(ElementT entry);
-
-  /**
-   * Synchronously sends any pending elements as a batch and waits for all outstanding batches to be
-   * complete.
-   */
-  void flush() throws InterruptedException;
-
-  /**
-   * Sends accumulated elements asynchronously for batching.
-   *
-   * <p>Note: This method can be invoked concurrently unlike {@link #add} and {@link #close}, which
-   * can only be called from a single user thread. Please take caution to avoid race condition.
-   */
-  void sendOutstanding();
-
-  /**
-   * Closes this Batcher by preventing new elements from being added, and then flushing the existing
-   * elements.
-   */
-  @Override
-  void close() throws InterruptedException;
-
-  /**
-   * Closes this Batcher by preventing new elements from being added, and then sending outstanding
-   * elements. The returned future will be resolved when the last element completes
-   */
-  ApiFuture<Void> closeAsync();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatcherImpl.java b/gax/src/main/java/com/google/api/gax/batching/BatcherImpl.java
deleted file mode 100644
index 2118ae24b..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatcherImpl.java
+++ /dev/null
@@ -1,600 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.api.gax.batching.FlowController.FlowControlRuntimeException;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import com.google.common.base.Stopwatch;
-import com.google.common.util.concurrent.Futures;
-import java.lang.ref.Reference;
-import java.lang.ref.ReferenceQueue;
-import java.lang.ref.SoftReference;
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import javax.annotation.Nullable;
-
-/**
- * Queues up the elements until {@link #flush()} is called; once batching is over, returned future
- * resolves.
- *
- * <p>This class is not thread-safe, and expects to be used from a single thread.
- *
- * @param <ElementT> The type of each individual element to be batched.
- * @param <ElementResultT> The type of the result for each individual element.
- * @param <RequestT> The type of the request that will contain the accumulated elements.
- * @param <ResponseT> The type of the response that will unpack into individual element results.
- */
-@InternalApi("For google-cloud-java client use only")
-public class BatcherImpl<ElementT, ElementResultT, RequestT, ResponseT>
-    implements Batcher<ElementT, ElementResultT> {
-
-  private static final Logger LOG = Logger.getLogger(BatcherImpl.class.getName());
-  private final BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT>
-      batchingDescriptor;
-  private final UnaryCallable<RequestT, ResponseT> unaryCallable;
-  private final RequestT prototype;
-  private final BatchingSettings batchingSettings;
-  private final BatcherReference currentBatcherReference;
-
-  private Batch<ElementT, ElementResultT, RequestT, ResponseT> currentOpenBatch;
-  private final AtomicInteger numOfOutstandingBatches = new AtomicInteger(0);
-  private final Object flushLock = new Object();
-  private final Object elementLock = new Object();
-  private final Future<?> scheduledFuture;
-  private SettableApiFuture<Void> closeFuture;
-  private final BatcherStats batcherStats = new BatcherStats();
-  private final FlowController flowController;
-  private final ApiCallContext callContext;
-
-  /**
-   * @param batchingDescriptor a {@link BatchingDescriptor} for transforming individual elements
-   *     into wrappers request and response
-   * @param unaryCallable a {@link UnaryCallable} object
-   * @param prototype a {@link RequestT} object
-   * @param batchingSettings a {@link BatchingSettings} with configuration of thresholds
-   * @deprecated Please instantiate the Batcher with {@link FlowController} and {@link
-   *     ApiCallContext}
-   */
-  @Deprecated
-  public BatcherImpl(
-      BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor,
-      UnaryCallable<RequestT, ResponseT> unaryCallable,
-      RequestT prototype,
-      BatchingSettings batchingSettings,
-      ScheduledExecutorService executor) {
-
-    this(batchingDescriptor, unaryCallable, prototype, batchingSettings, executor, null, null);
-  }
-
-  /**
-   * @param batchingDescriptor a {@link BatchingDescriptor} for transforming individual elements
-   *     into wrappers request and response
-   * @param unaryCallable a {@link UnaryCallable} object
-   * @param prototype a {@link RequestT} object
-   * @param batchingSettings a {@link BatchingSettings} with configuration of thresholds
-   * @param flowController a {@link FlowController} for throttling requests. If it's null, create a
-   *     {@link FlowController} object from {@link BatchingSettings#getFlowControlSettings()}.
-   * @deprecated Please instantiate the Batcher with {@link ApiCallContext}
-   */
-  @Deprecated
-  public BatcherImpl(
-      BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor,
-      UnaryCallable<RequestT, ResponseT> unaryCallable,
-      RequestT prototype,
-      BatchingSettings batchingSettings,
-      ScheduledExecutorService executor,
-      @Nullable FlowController flowController) {
-
-    this(
-        batchingDescriptor,
-        unaryCallable,
-        prototype,
-        batchingSettings,
-        executor,
-        flowController,
-        null);
-  }
-
-  /**
-   * @param batchingDescriptor a {@link BatchingDescriptor} for transforming individual elements
-   *     into wrappers request and response
-   * @param unaryCallable a {@link UnaryCallable} object
-   * @param prototype a {@link RequestT} object
-   * @param batchingSettings a {@link BatchingSettings} with configuration of thresholds
-   * @param flowController a {@link FlowController} for throttling requests. If it's null, create a
-   *     {@link FlowController} object from {@link BatchingSettings#getFlowControlSettings()}.
-   * @param callContext a {@link ApiCallContext} object that'll be merged in unaryCallable
-   */
-  public BatcherImpl(
-      BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor,
-      UnaryCallable<RequestT, ResponseT> unaryCallable,
-      RequestT prototype,
-      BatchingSettings batchingSettings,
-      ScheduledExecutorService executor,
-      @Nullable FlowController flowController,
-      @Nullable ApiCallContext callContext) {
-
-    this.batchingDescriptor =
-        Preconditions.checkNotNull(batchingDescriptor, "batching descriptor cannot be null");
-    this.unaryCallable = Preconditions.checkNotNull(unaryCallable, "callable cannot be null");
-    this.prototype = Preconditions.checkNotNull(prototype, "request prototype cannot be null");
-    this.batchingSettings =
-        Preconditions.checkNotNull(batchingSettings, "batching setting cannot be null");
-    Preconditions.checkNotNull(executor, "executor cannot be null");
-    if (flowController == null) {
-      flowController = new FlowController(batchingSettings.getFlowControlSettings());
-    }
-    // If throttling is enabled, make sure flow control limits are greater or equal to batch sizes
-    // to avoid deadlocking
-    if (flowController.getLimitExceededBehavior() != LimitExceededBehavior.Ignore) {
-      Preconditions.checkArgument(
-          flowController.getMaxElementCountLimit() == null
-              || batchingSettings.getElementCountThreshold() == null
-              || flowController.getMaxElementCountLimit()
-                  >= batchingSettings.getElementCountThreshold(),
-          "If throttling and batching on element count are enabled, FlowController"
-              + "#maxOutstandingElementCount must be greater or equal to elementCountThreshold");
-      Preconditions.checkArgument(
-          flowController.getMaxRequestBytesLimit() == null
-              || batchingSettings.getRequestByteThreshold() == null
-              || flowController.getMaxRequestBytesLimit()
-                  >= batchingSettings.getRequestByteThreshold(),
-          "If throttling and batching on request bytes are enabled, FlowController"
-              + "#maxOutstandingRequestBytes must be greater or equal to requestByteThreshold");
-    }
-    this.flowController = flowController;
-    currentOpenBatch = new Batch<>(prototype, batchingDescriptor, batchingSettings, batcherStats);
-    if (batchingSettings.getDelayThreshold() != null) {
-      long delay = batchingSettings.getDelayThreshold().toMillis();
-      PushCurrentBatchRunnable<ElementT, ElementResultT, RequestT, ResponseT> runnable =
-          new PushCurrentBatchRunnable<>(this);
-      scheduledFuture =
-          executor.scheduleWithFixedDelay(runnable, delay, delay, TimeUnit.MILLISECONDS);
-    } else {
-      scheduledFuture = Futures.immediateCancelledFuture();
-    }
-    currentBatcherReference = new BatcherReference(this);
-    this.callContext = callContext;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public ApiFuture<ElementResultT> add(ElementT element) {
-    // Note: there is no need to synchronize over closeFuture. The write & read of the variable
-    // will only be done from a single calling thread.
-    Preconditions.checkState(closeFuture == null, "Cannot add elements on a closed batcher");
-
-    long bytesSize = batchingDescriptor.countBytes(element);
-
-    // This is not the optimal way of throttling. It does not send out partial batches, which
-    // means that the Batcher might not use up all the resources allowed by FlowController.
-    // The more efficient implementation should look like:
-    // if (!flowController.tryReserve(1, bytes)) {
-    //   sendOutstanding();
-    //   reserve(1, bytes);
-    // }
-    // where tryReserve() will return false if there isn't enough resources, or reserve and return
-    // true.
-    // However, with the current FlowController implementation, adding a tryReserve() could be
-    // confusing. FlowController will end up having 3 different reserve behaviors: blocking,
-    // non blocking and try reserve. And we'll also need to add a tryAcquire() to the Semaphore64
-    // class, which made it seem unnecessary to have blocking and non-blocking semaphore
-    // implementations. Some refactoring may be needed for the optimized implementation. So we'll
-    // defer it till we decide on if refactoring FlowController is necessary.
-    Stopwatch stopwatch = Stopwatch.createStarted();
-    try {
-      flowController.reserve(1, bytesSize);
-    } catch (FlowControlException e) {
-      // This exception will only be thrown if the FlowController is set to ThrowException behavior
-      throw FlowControlRuntimeException.fromFlowControlException(e);
-    }
-    long throttledTimeMs = stopwatch.elapsed(TimeUnit.MILLISECONDS);
-
-    SettableApiFuture<ElementResultT> result = SettableApiFuture.create();
-    synchronized (elementLock) {
-      currentOpenBatch.add(element, result, throttledTimeMs);
-    }
-
-    if (currentOpenBatch.hasAnyThresholdReached()) {
-      sendOutstanding();
-    }
-    return result;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void flush() throws InterruptedException {
-    sendOutstanding();
-    awaitAllOutstandingBatches();
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void sendOutstanding() {
-    final Batch<ElementT, ElementResultT, RequestT, ResponseT> accumulatedBatch;
-
-    synchronized (elementLock) {
-      if (currentOpenBatch.isEmpty()) {
-        return;
-      }
-      accumulatedBatch = currentOpenBatch;
-      currentOpenBatch = new Batch<>(prototype, batchingDescriptor, batchingSettings, batcherStats);
-    }
-
-    // This check is for old clients that instantiated the batcher without ApiCallContext
-    ApiCallContext callContextWithOption = null;
-    if (callContext != null) {
-      callContextWithOption =
-          callContext.withOption(THROTTLED_TIME_KEY, accumulatedBatch.totalThrottledTimeMs);
-    }
-    final ApiFuture<ResponseT> batchResponse =
-        unaryCallable.futureCall(accumulatedBatch.builder.build(), callContextWithOption);
-
-    numOfOutstandingBatches.incrementAndGet();
-    ApiFutures.addCallback(
-        batchResponse,
-        new ApiFutureCallback<ResponseT>() {
-          @Override
-          public void onSuccess(ResponseT response) {
-            try {
-              flowController.release(accumulatedBatch.elementCounter, accumulatedBatch.byteCounter);
-              accumulatedBatch.onBatchSuccess(response);
-            } finally {
-              onBatchCompletion();
-            }
-          }
-
-          @Override
-          public void onFailure(Throwable throwable) {
-            try {
-              flowController.release(accumulatedBatch.elementCounter, accumulatedBatch.byteCounter);
-              accumulatedBatch.onBatchFailure(throwable);
-            } finally {
-              onBatchCompletion();
-            }
-          }
-        },
-        directExecutor());
-  }
-
-  private void onBatchCompletion() {
-    boolean shouldClose = false;
-
-    synchronized (flushLock) {
-      if (numOfOutstandingBatches.decrementAndGet() == 0) {
-        flushLock.notifyAll();
-        shouldClose = closeFuture != null;
-      }
-    }
-    if (shouldClose) {
-      BatchingException overallError = batcherStats.asException();
-      if (overallError != null) {
-        closeFuture.setException(overallError);
-      } else {
-        closeFuture.set(null);
-      }
-    }
-  }
-
-  private void awaitAllOutstandingBatches() throws InterruptedException {
-    while (numOfOutstandingBatches.get() > 0) {
-      synchronized (flushLock) {
-        // Check again under lock to avoid racing with onBatchCompletion
-        if (numOfOutstandingBatches.get() == 0) {
-          break;
-        }
-        flushLock.wait();
-      }
-    }
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void close() throws InterruptedException {
-    try {
-      closeAsync().get();
-    } catch (ExecutionException e) {
-      // Original stacktrace of a batching exception is not useful, so rethrow the error with
-      // the caller stacktrace
-      if (e.getCause() instanceof BatchingException) {
-        BatchingException cause = (BatchingException) e.getCause();
-        throw new BatchingException(cause.getMessage());
-      } else {
-        throw new IllegalStateException("unexpected error closing the batcher", e.getCause());
-      }
-    }
-  }
-
-  @Override
-  public ApiFuture<Void> closeAsync() {
-    if (closeFuture != null) {
-      return closeFuture;
-    }
-
-    // Send any buffered elements
-    // Must come before numOfOutstandingBatches check below
-    sendOutstanding();
-
-    boolean closeImmediately;
-
-    synchronized (flushLock) {
-      // prevent admission of new elements
-      closeFuture = SettableApiFuture.create();
-      // check if we can close immediately
-      closeImmediately = numOfOutstandingBatches.get() == 0;
-    }
-
-    // Clean up accounting
-    scheduledFuture.cancel(false);
-    currentBatcherReference.closed = true;
-    currentBatcherReference.clear();
-
-    // notify futures
-    if (closeImmediately) {
-      finishClose();
-    }
-    return closeFuture;
-  }
-
-  private void finishClose() {
-    BatchingException batchingException = batcherStats.asException();
-    if (batchingException != null) {
-      closeFuture.setException(batchingException);
-    } else {
-      closeFuture.set(null);
-    }
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  public FlowController getFlowController() {
-    return flowController;
-  }
-
-  /**
-   * This class represent one logical Batch. It accumulates all the elements and their corresponding
-   * future results for one batch.
-   */
-  private static class Batch<ElementT, ElementResultT, RequestT, ResponseT> {
-    private final BatchingRequestBuilder<ElementT, RequestT> builder;
-    private final List<BatchEntry<ElementT, ElementResultT>> entries;
-    private final BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> descriptor;
-    private final BatcherStats batcherStats;
-    private final long elementThreshold;
-    private final long bytesThreshold;
-
-    private long elementCounter = 0;
-    private long byteCounter = 0;
-    private long totalThrottledTimeMs = 0;
-
-    private Batch(
-        RequestT prototype,
-        BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> descriptor,
-        BatchingSettings batchingSettings,
-        BatcherStats batcherStats) {
-      this.descriptor = descriptor;
-      this.builder = descriptor.newRequestBuilder(prototype);
-      this.entries = new ArrayList<>();
-      Long elementCountThreshold = batchingSettings.getElementCountThreshold();
-      this.elementThreshold = elementCountThreshold == null ? 0 : elementCountThreshold;
-      Long requestByteThreshold = batchingSettings.getRequestByteThreshold();
-      this.bytesThreshold = requestByteThreshold == null ? 0 : requestByteThreshold;
-      this.batcherStats = batcherStats;
-    }
-
-    void add(ElementT element, SettableApiFuture<ElementResultT> result, long throttledTimeMs) {
-      builder.add(element);
-      entries.add(BatchEntry.create(element, result));
-      elementCounter++;
-      byteCounter += descriptor.countBytes(element);
-      totalThrottledTimeMs += throttledTimeMs;
-    }
-
-    void onBatchSuccess(ResponseT response) {
-      try {
-        descriptor.splitResponse(response, entries);
-        batcherStats.recordBatchElementsCompletion(entries);
-      } catch (Exception ex) {
-        onBatchFailure(ex);
-      }
-    }
-
-    void onBatchFailure(Throwable throwable) {
-      try {
-        descriptor.splitException(throwable, entries);
-      } catch (Exception ex) {
-        for (BatchEntry<ElementT, ElementResultT> batchEntry : entries) {
-          batchEntry.getResultFuture().setException(ex);
-        }
-      }
-      batcherStats.recordBatchFailure(throwable);
-    }
-
-    boolean isEmpty() {
-      return elementCounter == 0;
-    }
-
-    boolean hasAnyThresholdReached() {
-      return elementCounter >= elementThreshold || byteCounter >= bytesThreshold;
-    }
-  }
-
-  /**
-   * Executes {@link #sendOutstanding()} on a periodic interval.
-   *
-   * <p>This class holds a weak reference to the Batcher instance and cancels polling if the target
-   * Batcher has been garbage collected.
-   */
-  @VisibleForTesting
-  static class PushCurrentBatchRunnable<ElementT, ElementResultT, RequestT, ResponseT>
-      implements Runnable {
-
-    private Future<?> scheduledFuture;
-    private final WeakReference<BatcherImpl<ElementT, ElementResultT, RequestT, ResponseT>>
-        batcherReferent;
-
-    PushCurrentBatchRunnable(BatcherImpl<ElementT, ElementResultT, RequestT, ResponseT> batcher) {
-      this.batcherReferent = new WeakReference<>(batcher);
-    }
-
-    @Override
-    public void run() {
-      BatcherImpl<ElementT, ElementResultT, RequestT, ResponseT> batcher = batcherReferent.get();
-      if (batcher == null) {
-        scheduledFuture.cancel(true);
-      } else {
-        batcher.sendOutstanding();
-      }
-    }
-
-    void setScheduledFuture(Future<?> scheduledFuture) {
-      this.scheduledFuture = scheduledFuture;
-    }
-
-    boolean isCancelled() {
-      return scheduledFuture.isCancelled();
-    }
-  }
-
-  /**
-   * On every Batcher allocation this class will check for garbage collected batchers that were
-   * never closed and emit warning logs.
-   */
-  @VisibleForTesting
-  static final class BatcherReference extends WeakReference<BatcherImpl> {
-
-    private static final ReferenceQueue<BatcherImpl> refQueue = new ReferenceQueue<>();
-
-    // Retain the References so they don't get GC'd
-    private static final ConcurrentMap<BatcherReference, BatcherReference> refs =
-        new ConcurrentHashMap<>();
-
-    private static final String ALLOCATION_SITE_PROPERTY_NAME =
-        "com.google.api.gax.batching.Batcher.enableAllocationTracking";
-
-    private static final boolean ENABLE_ALLOCATION_TRACKING =
-        Boolean.parseBoolean(System.getProperty(ALLOCATION_SITE_PROPERTY_NAME, "true"));
-    private static final RuntimeException missingCallSite = missingCallSite();
-
-    private final Reference<RuntimeException> allocationSite;
-    private volatile boolean closed;
-
-    BatcherReference(BatcherImpl referent) {
-      super(referent, refQueue);
-      // allocationSite is softReference to make it garbage collectible, but delay it as long as
-      // possible as BatcherReference can only be weakly referred.
-      allocationSite =
-          new SoftReference<>(
-              ENABLE_ALLOCATION_TRACKING
-                  ? new RuntimeException("Batcher allocation site")
-                  : missingCallSite);
-      refs.put(this, this);
-      cleanQueue();
-    }
-
-    /**
-     * This clear() is *not* called automatically by the JVM. As this is a weak ref, the reference
-     * will be cleared automatically by the JVM, but will not be removed from {@link #refs}. We do
-     * it here to avoid this ending up on the reference queue.
-     */
-    @Override
-    public void clear() {
-      clearInternal();
-      // We run this here to periodically clean up the queue if any Batcher is being
-      // closed properly.
-      cleanQueue();
-    }
-
-    private void clearInternal() {
-      super.clear();
-      refs.remove(this);
-      allocationSite.clear();
-    }
-
-    /**
-     * It performs below tasks:
-     *
-     * <ul>
-     *   <li>Check each batcher registered on refQueue while initialization.
-     *   <li>Unregister them from refQueue.
-     *   <li>If close() is not called on the batcher, then emits log with possible allocationSite.
-     *   <li>Keeps track of number of batcher on which close() is not called.
-     * </ul>
-     */
-    @VisibleForTesting
-    static int cleanQueue() {
-      BatcherReference ref;
-      int orphanedBatchers = 0;
-      while ((ref = (BatcherReference) refQueue.poll()) != null) {
-        RuntimeException maybeAllocationSite = ref.allocationSite.get();
-        ref.clearInternal(); // technically the reference is gone already.
-        if (!ref.closed) {
-          orphanedBatchers++;
-          if (LOG.isLoggable(Level.SEVERE)) {
-            String message = "Batcher was not closed properly!!! Make sure to call close().";
-            LOG.log(Level.SEVERE, message, maybeAllocationSite);
-          }
-        }
-      }
-      return orphanedBatchers;
-    }
-
-    private static RuntimeException missingCallSite() {
-      RuntimeException e =
-          new RuntimeException(
-              "Batcher allocation site not recorded.  Set -D"
-                  + ALLOCATION_SITE_PROPERTY_NAME
-                  + "=true to enable it");
-      e.setStackTrace(new StackTraceElement[0]);
-      return e;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatcherStats.java b/gax/src/main/java/com/google/api/gax/batching/BatcherStats.java
deleted file mode 100644
index 784af6f59..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatcherStats.java
+++ /dev/null
@@ -1,184 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.base.MoreObjects;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import javax.annotation.Nullable;
-
-/**
- * Keeps the statistics about failed operations(both at RPC and ElementT) in {@link Batcher}. This
- * provides the count of individual exception failure and count of each failed {@link Code} occurred
- * in the batching process.
- */
-class BatcherStats {
-
-  private final Map<Class, Integer> requestExceptionCounts = new HashMap<>();
-  private final Map<Code, Integer> requestStatusCounts = new HashMap<>();
-  private int requestPartialFailureCount;
-
-  private final Map<Class, Integer> entryExceptionCounts = new HashMap<>();
-  private final Map<Code, Integer> entryStatusCounts = new HashMap<>();
-
-  /**
-   * Records the count of the exception and it's type when a complete batch failed to apply.
-   *
-   * <p>Note: This method aggregates all the subclasses of {@link ApiException} under ApiException
-   * using the {@link Code status codes} and its number of occurrences.
-   */
-  synchronized void recordBatchFailure(Throwable throwable) {
-    Class exceptionClass = throwable.getClass();
-
-    if (throwable instanceof ApiException) {
-      Code code = ((ApiException) throwable).getStatusCode().getCode();
-      exceptionClass = ApiException.class;
-
-      int oldStatusCount = MoreObjects.firstNonNull(requestStatusCounts.get(code), 0);
-      requestStatusCounts.put(code, oldStatusCount + 1);
-    }
-
-    int oldExceptionCount = MoreObjects.firstNonNull(requestExceptionCounts.get(exceptionClass), 0);
-    requestExceptionCounts.put(exceptionClass, oldExceptionCount + 1);
-  }
-
-  /**
-   * Records partial failures within each batch. partialBatchFailures counts the number of batches
-   * that have at least one failed entry while entryStatusCounts and entryExceptionCounts track the
-   * count of the entries themselves.
-   *
-   * <p>Note: This method aggregates all the subclasses of {@link ApiException} under ApiException
-   * using the {@link Code status codes} and its number of occurrences.
-   */
-  synchronized <T extends BatchEntry> void recordBatchElementsCompletion(
-      List<T> batchElementResultFutures) {
-    boolean isRequestPartiallyFailed = false;
-    for (final BatchEntry elementResult : batchElementResultFutures) {
-      try {
-        elementResult.getResultFuture().get();
-      } catch (Throwable throwable) {
-
-        if (!isRequestPartiallyFailed) {
-          isRequestPartiallyFailed = true;
-          requestPartialFailureCount++;
-        }
-        Throwable actualCause = throwable.getCause();
-        Class exceptionClass = actualCause.getClass();
-
-        if (actualCause instanceof ApiException) {
-          Code code = ((ApiException) actualCause).getStatusCode().getCode();
-          exceptionClass = ApiException.class;
-
-          int oldStatusCount = MoreObjects.firstNonNull(entryStatusCounts.get(code), 0);
-          entryStatusCounts.put(code, oldStatusCount + 1);
-        }
-
-        int oldExceptionCount =
-            MoreObjects.firstNonNull(entryExceptionCounts.get(exceptionClass), 0);
-        entryExceptionCounts.put(exceptionClass, oldExceptionCount + 1);
-      }
-    }
-  }
-
-  /** Calculates and formats the message with request and entry failure count. */
-  @Nullable
-  synchronized BatchingException asException() {
-    if (requestExceptionCounts.isEmpty() && requestPartialFailureCount == 0) {
-      return null;
-    }
-
-    StringBuilder messageBuilder = new StringBuilder();
-    messageBuilder.append("Batching finished with ");
-
-    if (!requestExceptionCounts.isEmpty()) {
-      messageBuilder
-          .append(
-              String.format("%d batches failed to apply due to: ", requestExceptionCounts.size()))
-          .append(buildExceptionList(requestExceptionCounts, requestStatusCounts))
-          .append(" and ");
-    }
-
-    messageBuilder.append(String.format("%d partial failures.", requestPartialFailureCount));
-    if (requestPartialFailureCount > 0) {
-      int totalEntriesCount = 0;
-      for (Integer count : entryExceptionCounts.values()) {
-        totalEntriesCount += count;
-      }
-
-      messageBuilder
-          .append(
-              String.format(
-                  " The %d partial failures contained %d entries that failed with: ",
-                  requestPartialFailureCount, totalEntriesCount))
-          .append(buildExceptionList(entryExceptionCounts, entryStatusCounts))
-          .append(".");
-    }
-    return new BatchingException(messageBuilder.toString());
-  }
-
-  /**
-   * Prints the class name and it's count along with {@link Code status code} and it's counts.
-   *
-   * <p>Example: "1 IllegalStateException, 1 ApiException(1 UNAVAILABLE, 1 ALREADY_EXISTS)".
-   */
-  private String buildExceptionList(
-      Map<Class, Integer> exceptionCounts, Map<Code, Integer> statusCounts) {
-    StringBuilder messageBuilder = new StringBuilder();
-    Iterator<Map.Entry<Class, Integer>> exceptionIterator = exceptionCounts.entrySet().iterator();
-
-    while (exceptionIterator.hasNext()) {
-      Map.Entry<Class, Integer> request = exceptionIterator.next();
-      messageBuilder.append(
-          String.format("%d %s", request.getValue(), request.getKey().getSimpleName()));
-
-      if (ApiException.class.equals(request.getKey())) {
-        messageBuilder.append("(");
-        Iterator<Map.Entry<Code, Integer>> statusIterator = statusCounts.entrySet().iterator();
-        while (statusIterator.hasNext()) {
-          Map.Entry<Code, Integer> statusCode = statusIterator.next();
-          messageBuilder.append(String.format("%d %s", statusCode.getValue(), statusCode.getKey()));
-          if (statusIterator.hasNext()) {
-            messageBuilder.append(", ");
-          }
-        }
-        messageBuilder.append(")");
-      }
-      if (exceptionIterator.hasNext()) {
-        messageBuilder.append(", ");
-      }
-    }
-
-    return messageBuilder.toString();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingCallSettings.java b/gax/src/main/java/com/google/api/gax/batching/BatchingCallSettings.java
deleted file mode 100644
index f7a25ae77..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingCallSettings.java
+++ /dev/null
@@ -1,179 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import java.util.Set;
-
-/**
- * This is an extension of {@link UnaryCallSettings} class to configure a {@link UnaryCallable} for
- * calls to an API method that supports batching. The batching settings are provided using the
- * instance of {@link BatchingSettings}.
- *
- * <p>Retry configuration will be applied on each batching RPC request.
- *
- * <p>Sample settings configuration:
- *
- * <pre>{@code
- * BatchingCallSettings batchingCallSettings = // Default BatchingCallSettings from the client
- * BatchingCallSettings customBatchingCallSettings =
- *     batchingCallSettings
- *         .toBuilder()
- *         .setRetryableCodes(StatusCode.Code.UNAVAILABLE, ...)
- *         .setRetrySettings(RetrySettings.newBuilder()...build())
- *         .setBatchingSettings(BatchingSettings.newBuilder()...build())
- *         .build();
- * }</pre>
- *
- * @param <ElementT> The type of each individual element to be batched.
- * @param <ElementResultT> The type of the result for each individual element.
- * @param <RequestT> The type of the request that will contain the accumulated elements.
- * @param <ResponseT> The type of the response that will unpack into individual element results.
- */
-public final class BatchingCallSettings<ElementT, ElementResultT, RequestT, ResponseT>
-    extends UnaryCallSettings<RequestT, ResponseT> {
-  private final BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT>
-      batchingDescriptor;
-  private final BatchingSettings batchingSettings;
-
-  @InternalApi("For google-cloud-java client use only")
-  public BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> getBatchingDescriptor() {
-    return batchingDescriptor;
-  }
-
-  /** Returns batching settings which contains multiple batch threshold levels. */
-  public BatchingSettings getBatchingSettings() {
-    return batchingSettings;
-  }
-
-  private BatchingCallSettings(Builder<ElementT, ElementResultT, RequestT, ResponseT> builder) {
-    super(builder);
-    Preconditions.checkState(builder.batchingSettings != null, "batching settings cannot be null");
-    this.batchingDescriptor = builder.batchingDescriptor;
-    this.batchingSettings = builder.batchingSettings;
-  }
-
-  /** Please use {@link #toBuilder()} to override settings values. */
-  @InternalApi("For google-cloud-java client use only")
-  public static <ElementT, ElementResultT, RequestT, ResponseT>
-      Builder<ElementT, ElementResultT, RequestT, ResponseT> newBuilder(
-          BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor) {
-    return new Builder<>(batchingDescriptor);
-  }
-
-  /**
-   * Get a builder with the same values as this object. See the class documentation of {@link
-   * BatchingCallSettings} for a sample settings configuration.
-   */
-  @Override
-  public final Builder<ElementT, ElementResultT, RequestT, ResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("retryableCodes", getRetryableCodes())
-        .add("retrySettings", getRetrySettings())
-        .add("batchingSettings", batchingSettings)
-        .toString();
-  }
-
-  /**
-   * A base builder class for {@link BatchingCallSettings}. See the class documentation of {@link
-   * BatchingCallSettings} for a description of the different values that can be set.
-   */
-  public static class Builder<ElementT, ElementResultT, RequestT, ResponseT>
-      extends UnaryCallSettings.Builder<RequestT, ResponseT> {
-
-    private BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor;
-    private BatchingSettings batchingSettings;
-
-    private Builder(
-        BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> batchingDescriptor) {
-      this.batchingDescriptor =
-          Preconditions.checkNotNull(batchingDescriptor, "batching descriptor cannot be null");
-    }
-
-    private Builder(BatchingCallSettings<ElementT, ElementResultT, RequestT, ResponseT> settings) {
-      super(settings);
-      this.batchingDescriptor = settings.batchingDescriptor;
-      this.batchingSettings = settings.batchingSettings;
-    }
-
-    /** Sets the batching settings with various thresholds. */
-    public Builder<ElementT, ElementResultT, RequestT, ResponseT> setBatchingSettings(
-        BatchingSettings batchingSettings) {
-      this.batchingSettings = batchingSettings;
-      return this;
-    }
-
-    /** Returns the {@link BatchingSettings}. */
-    public BatchingSettings getBatchingSettings() {
-      return batchingSettings;
-    }
-
-    /** Sets the rpc failure {@link StatusCode.Code code}, for which retries should be performed. */
-    @Override
-    public Builder<ElementT, ElementResultT, RequestT, ResponseT> setRetryableCodes(
-        StatusCode.Code... codes) {
-      super.setRetryableCodes(codes);
-      return this;
-    }
-
-    /** Sets the rpc failure {@link StatusCode.Code code}, for which retries should be performed. */
-    @Override
-    public Builder<ElementT, ElementResultT, RequestT, ResponseT> setRetryableCodes(
-        Set<StatusCode.Code> retryableCodes) {
-      super.setRetryableCodes(retryableCodes);
-      return this;
-    }
-
-    /** Sets the {@link RetrySettings} values for each retry attempts. */
-    @Override
-    public Builder<ElementT, ElementResultT, RequestT, ResponseT> setRetrySettings(
-        RetrySettings retrySettings) {
-      super.setRetrySettings(retrySettings);
-      return this;
-    }
-
-    /** Builds the {@link BatchingCallSettings} object with provided configuration. */
-    @Override
-    public BatchingCallSettings<ElementT, ElementResultT, RequestT, ResponseT> build() {
-      return new BatchingCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingDescriptor.java b/gax/src/main/java/com/google/api/gax/batching/BatchingDescriptor.java
deleted file mode 100644
index d81068a98..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingDescriptor.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-import java.util.List;
-
-/**
- * An adapter that packs and unpacks the elements in and out of batch requests and responses.
- *
- * <p>This interface should be implemented by either a service specific client or autogenerated by
- * gapic-generator.
- *
- * <p>Example implementation:
- *
- * <pre>{@code
- * class ListDescriptor implements BatchingDescriptor<String, String, List<String>, List<String>> {
- *
- *   RequestBuilder<String, List<String>> newRequestBuilder(List<String> prototype) {
- *     return new RequestBuilder<String, List<String>>() {
- *
- *       void add(String element) {
- *         list.add(element);
- *       }
- *
- *       List<String> build() {
- *         return list.clone();
- *       }
- *     };
- *   }
- *
- *   void splitResponse(List<String> callableResponse, List<SettableApiFuture<String>> batch) {
- *     for (int i = 0; i < batchResponse.size(); i++) {
- *       batch.get(i).set(batchResponse.get(i);
- *     }
- *   }
- *
- *   void splitException(Throwable throwable, List<SettableApiFuture<String>> batch) {
- *     for (SettableApiFuture<String> result : batch) {
- *       result.setException(throwable);
- *     }
- *   }
- *
- *   long countBytes(String element) {
- *     return element.length();
- *   }
- * }
- * }</pre>
- *
- * @param <ElementT> The type of each individual element to be batched
- * @param <ElementResultT> The type of the result for each individual element
- * @param <RequestT> The type of the request that will contain the accumulated elements
- * @param <ResponseT> The type of the response that will be unpacked into individual element results
- */
-@InternalApi("For google-cloud-java client use only.")
-public interface BatchingDescriptor<ElementT, ElementResultT, RequestT, ResponseT> {
-
-  /**
-   * Creates a new wrapper for the underlying request builder. It's used to pack the current batch
-   * request with elements.
-   */
-  BatchingRequestBuilder<ElementT, RequestT> newRequestBuilder(RequestT prototype);
-
-  /** Unpacks the batch response into individual elements results. */
-  void splitResponse(ResponseT batchResponse, List<BatchEntry<ElementT, ElementResultT>> batch);
-
-  /** Unpacks the batch response error into individual element errors. */
-  void splitException(Throwable throwable, List<BatchEntry<ElementT, ElementResultT>> batch);
-
-  /** Returns the size of the passed element object in bytes. */
-  long countBytes(ElementT element);
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingException.java b/gax/src/main/java/com/google/api/gax/batching/BatchingException.java
deleted file mode 100644
index 470c659d0..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingException.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-/** Represents exception occurred during batching. */
-public final class BatchingException extends RuntimeException {
-
-  BatchingException(String message) {
-    super(message);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingFlowController.java b/gax/src/main/java/com/google/api/gax/batching/BatchingFlowController.java
deleted file mode 100644
index 4252f7594..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingFlowController.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.common.base.Preconditions;
-import com.google.common.primitives.Ints;
-
-/** Wraps a {@link FlowController} for use by batching. */
-public class BatchingFlowController<T> {
-
-  private final FlowController flowController;
-  private final ElementCounter<T> elementCounter;
-  private final ElementCounter<T> byteCounter;
-
-  public BatchingFlowController(
-      FlowController flowController,
-      ElementCounter<T> elementCounter,
-      ElementCounter<T> byteCounter) {
-    this.flowController = flowController;
-    this.elementCounter = elementCounter;
-    this.byteCounter = byteCounter;
-  }
-
-  public void reserve(T batch) throws FlowControlException {
-    Preconditions.checkNotNull(batch);
-    int elements = Ints.checkedCast(elementCounter.count(batch));
-    int bytes = Ints.checkedCast(byteCounter.count(batch));
-    flowController.reserve(elements, bytes);
-  }
-
-  public void release(T batch) {
-    Preconditions.checkNotNull(batch);
-    int elements = Ints.checkedCast(elementCounter.count(batch));
-    int bytes = Ints.checkedCast(byteCounter.count(batch));
-    flowController.release(elements, bytes);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingRequestBuilder.java b/gax/src/main/java/com/google/api/gax/batching/BatchingRequestBuilder.java
deleted file mode 100644
index 448e15c5b..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingRequestBuilder.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-
-/**
- * Adapter to pack individual elements into a larger batch request.
- *
- * <p>The implementation for this interface will be implemented by service specific client or auto
- * generated by the gapic-generator.
- *
- * @param <ElementT> The type of each individual element to be batched.
- * @param <RequestT> The type of the request that will contain the accumulated elements.
- */
-@InternalApi("For google-cloud-java client use only.")
-public interface BatchingRequestBuilder<ElementT, RequestT> {
-
-  /** Adds element object into client specific batch request. */
-  void add(ElementT element);
-
-  /** Returns the collected elements as a single client specific batch request. */
-  RequestT build();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingSettings.java b/gax/src/main/java/com/google/api/gax/batching/BatchingSettings.java
deleted file mode 100644
index 8982c46ff..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingSettings.java
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.auto.value.AutoValue;
-import com.google.common.base.Preconditions;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * Represents the batching settings to use for an API method that is capable of batching.
- *
- * <p>By default the settings are configured to <b>not</b> use batching (i.e. the batch size
- * threshold is 1). This is the safest default behavior, which has meaning in all possible
- * scenarios. Users are expected to configure actual batching thresholds explicitly: the element
- * count, the request bytes count and the delay.
- *
- * <p>Warning: With the wrong settings, it is possible to cause long periods of dead waiting time.
- *
- * <p>When batching is turned on for an API method, a call to that method will result in the request
- * being queued up with other requests. When any of the set thresholds are reached, the queued up
- * requests are packaged together in a batch and set to the service as a single RPC. When the
- * response comes back, it is split apart into individual responses according to the individual
- * input requests.
- *
- * <p>There are several supported thresholds:
- *
- * <ul>
- *   <li><b>Delay Threshold</b>: Counting from the time that the first message is queued, once this
- *       delay has passed, then send the batch. The default value is 1 millisecond.
- *   <li><b>Message Count Threshold</b>: Once this many messages are queued, send all of the
- *       messages in a single call, even if the delay threshold hasn't elapsed yet. The default
- *       value is 1 message.
- *   <li><b>Request Byte Threshold</b>: Once the number of bytes in the batched request reaches this
- *       threshold, send all of the messages in a single call, even if neither the delay or message
- *       count thresholds have been exceeded yet. The default value is 1 byte.
- * </ul>
- *
- * <p>These thresholds are treated as triggers, not as limits. Thus, if a request is made with 2x
- * the message count threshold, it will not be split apart (unless one of the limits listed further
- * down is crossed); only one batch will be sent. Each threshold is an independent trigger and
- * doesn't have any knowledge of the other thresholds.
- *
- * <p>Two of the values above also have limits:
- *
- * <ul>
- *   <li><b>Message Count Limit</b>: The limit of the number of messages that the server will accept
- *       in a single request.
- *   <li><b>Request Byte Limit</b>: The limit of the byte size of a request that the server will
- *       accept.
- * </ul>
- *
- * <p>For these values, individual requests that surpass the limit are rejected, and the batching
- * logic will not batch together requests if the resulting batch will surpass the limit. Thus, a
- * batch can be sent that is actually under the threshold if the next request would put the combined
- * request over the limit.
- *
- * <p>Batching also supports FlowControl. This can be used to prevent the batching implementation
- * from accumulating messages without limit, resulting eventually in an OutOfMemory exception. This
- * can occur if messages are created and added to batching faster than they can be processed. The
- * flow control behavior is controlled using FlowControlSettings.
- */
-@AutoValue
-public abstract class BatchingSettings {
-  /** Get the element count threshold to use for batching. */
-  @Nullable
-  public abstract Long getElementCountThreshold();
-
-  /** Get the request byte threshold to use for batching. */
-  @Nullable
-  public abstract Long getRequestByteThreshold();
-
-  /** Get the delay threshold to use for batching. */
-  @Nullable
-  public abstract Duration getDelayThreshold();
-
-  /** Returns the Boolean object to indicate if the batching is enabled. Default to true */
-  public abstract Boolean getIsEnabled();
-
-  /** Get the flow control settings to use. */
-  public abstract FlowControlSettings getFlowControlSettings();
-
-  /** Get a new builder. */
-  public static Builder newBuilder() {
-    return new AutoValue_BatchingSettings.Builder()
-        .setIsEnabled(true)
-        .setElementCountThreshold(1L)
-        .setRequestByteThreshold(1L)
-        .setDelayThreshold(Duration.ofMillis(1))
-        .setFlowControlSettings(
-            FlowControlSettings.newBuilder()
-                .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-                .build());
-  }
-
-  /** Get a builder with the same values as this object. */
-  public abstract Builder toBuilder();
-
-  /**
-   * See the class documentation of {@link BatchingSettings} for a description of the different
-   * values that can be set.
-   */
-  @AutoValue.Builder
-  public abstract static class Builder {
-    /**
-     * Set the element count threshold to use for batching. After this many elements are
-     * accumulated, they will be wrapped up in a batch and sent.
-     */
-    public abstract Builder setElementCountThreshold(Long elementCountThreshold);
-
-    /**
-     * Set the request byte threshold to use for batching. After this many bytes are accumulated,
-     * the elements will be wrapped up in a batch and sent.
-     */
-    public abstract Builder setRequestByteThreshold(Long requestByteThreshold);
-
-    /**
-     * Set the delay threshold to use for batching. After this amount of time has elapsed (counting
-     * from the first element added), the elements will be wrapped up in a batch and sent. This
-     * value should not be set too high, usually on the order of milliseconds. Otherwise, calls
-     * might appear to never complete.
-     */
-    public abstract Builder setDelayThreshold(Duration delayThreshold);
-
-    /**
-     * Set if the batch should be enabled. If set to false, the batch logic will be disabled and the
-     * simple API call will be used. Default to true.
-     */
-    public abstract Builder setIsEnabled(Boolean enabled);
-
-    /** Set the flow control settings to be used. */
-    public abstract Builder setFlowControlSettings(FlowControlSettings flowControlSettings);
-
-    abstract BatchingSettings autoBuild();
-
-    /** Build the BatchingSettings object. */
-    public BatchingSettings build() {
-      BatchingSettings settings = autoBuild();
-      Preconditions.checkArgument(
-          settings.getElementCountThreshold() == null || settings.getElementCountThreshold() > 0,
-          "elementCountThreshold must be either unset or positive");
-      Preconditions.checkArgument(
-          settings.getRequestByteThreshold() == null || settings.getRequestByteThreshold() > 0,
-          "requestByteThreshold must be either unset or positive");
-      Preconditions.checkArgument(
-          settings.getDelayThreshold() == null
-              || settings.getDelayThreshold().compareTo(Duration.ZERO) > 0,
-          "delayThreshold must be either unset or positive");
-      return settings;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingThreshold.java b/gax/src/main/java/com/google/api/gax/batching/BatchingThreshold.java
deleted file mode 100644
index 02ceabdb1..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingThreshold.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-/**
- * The interface representing a threshold to be used in ThresholdBatcher. Thresholds do not need to
- * be thread-safe if they are only used inside ThresholdBatcher.
- */
-public interface BatchingThreshold<E> {
-
-  /**
-   * Presents the element to the threshold for the attribute of interest to be accumulated.
-   *
-   * <p>Any calls into this function from ThresholdBatcher will be under a lock.
-   */
-  void accumulate(E e);
-
-  /**
-   * Any calls into this function from ThresholdBatcher will be under a lock.
-   *
-   * @return whether the threshold has been reached.
-   */
-  boolean isThresholdReached();
-
-  /**
-   * Make a copy of this threshold but with the accumulated value zeroed.
-   *
-   * <p>Any calls into this function from ThresholdBatcher will be under a lock.
-   */
-  BatchingThreshold<E> copyWithZeroedValue();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BatchingThresholds.java b/gax/src/main/java/com/google/api/gax/batching/BatchingThresholds.java
deleted file mode 100644
index 28409b00b..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BatchingThresholds.java
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.common.collect.ImmutableList;
-import java.util.List;
-
-/** Factory methods for general-purpose batching thresholds. */
-public final class BatchingThresholds {
-
-  /**
-   * Creates an ImmutableList containing only a single threshold which counts the number of
-   * elements. This is helpful for when using ThresholdBatcher for the simple case, when the element
-   * count is the only threshold.
-   */
-  public static <E> List<BatchingThreshold<E>> create(long elementThreshold) {
-    BatchingThreshold<E> batchingThreshold =
-        new NumericThreshold<>(
-            elementThreshold,
-            new ElementCounter<E>() {
-              @Override
-              public long count(E e) {
-                return 1;
-              }
-            });
-    return ImmutableList.of(batchingThreshold);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/BlockingSemaphore.java b/gax/src/main/java/com/google/api/gax/batching/BlockingSemaphore.java
deleted file mode 100644
index 0271f7e8a..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/BlockingSemaphore.java
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.batching;
-
-import com.google.common.base.Preconditions;
-
-/** A {@link Semaphore64} that blocks until permits become available. */
-class BlockingSemaphore implements Semaphore64 {
-  private long availablePermits;
-  private long limit;
-
-  private static void checkNotNegative(long l) {
-    Preconditions.checkArgument(l >= 0, "negative permits not allowed: %s", l);
-  }
-
-  BlockingSemaphore(long permits) {
-    checkNotNegative(permits);
-    this.availablePermits = permits;
-    this.limit = permits;
-  }
-
-  @Override
-  public synchronized void release(long permits) {
-    checkNotNegative(permits);
-    // TODO: throw exceptions when the permits overflow
-    availablePermits = Math.min(availablePermits + permits, limit);
-    notifyAll();
-  }
-
-  @Override
-  public synchronized boolean acquire(long permits) {
-    checkNotNegative(permits);
-
-    boolean interrupted = false;
-    while (availablePermits < permits) {
-      try {
-        wait();
-      } catch (InterruptedException e) {
-        interrupted = true;
-      }
-    }
-    // TODO: if thread is interrupted, we should not grant the permits
-    availablePermits -= permits;
-
-    if (interrupted) {
-      Thread.currentThread().interrupt();
-    }
-    return true;
-  }
-
-  @Override
-  public synchronized boolean acquirePartial(long permits) {
-    checkNotNegative(permits);
-
-    boolean interrupted = false;
-    // To allow individual oversized requests to be sent, clamp the requested permits to the maximum
-    // limit. This will allow individual large requests to be sent. Please note that this behavior
-    // will result in availablePermits going negative.
-    while (availablePermits < Math.min(limit, permits)) {
-      try {
-        wait();
-      } catch (InterruptedException e) {
-        interrupted = true;
-      }
-    }
-
-    if (interrupted) {
-      Thread.currentThread().interrupt();
-    }
-
-    availablePermits -= permits;
-    return true;
-  }
-
-  @Override
-  public synchronized void increasePermitLimit(long permits) {
-    checkNotNegative(permits);
-    availablePermits += permits;
-    limit += permits;
-    notifyAll();
-  }
-
-  @Override
-  public synchronized void reducePermitLimit(long reduction) {
-    checkNotNegative(reduction);
-    Preconditions.checkState(limit - reduction > 0, "permit limit underflow");
-    availablePermits -= reduction;
-    limit -= reduction;
-  }
-
-  @Override
-  public synchronized long getPermitLimit() {
-    return limit;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/DynamicFlowControlSettings.java b/gax/src/main/java/com/google/api/gax/batching/DynamicFlowControlSettings.java
deleted file mode 100644
index 95025183a..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/DynamicFlowControlSettings.java
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.auto.value.AutoValue;
-import com.google.common.base.Preconditions;
-import javax.annotation.Nullable;
-
-/** Settings for dynamic flow control */
-@AutoValue
-@InternalApi("For google-cloud-java client use only")
-public abstract class DynamicFlowControlSettings {
-
-  /** Number of outstanding elements that {@link FlowController} allows when it's initiated. */
-  @Nullable
-  public abstract Long getInitialOutstandingElementCount();
-
-  /** Number of outstanding bytes that {@link FlowController} allows when it's initiated. */
-  @Nullable
-  public abstract Long getInitialOutstandingRequestBytes();
-
-  /**
-   * Maximum number of outstanding elements {@link FlowController} allows before enforcing flow
-   * control.
-   */
-  @Nullable
-  public abstract Long getMaxOutstandingElementCount();
-
-  /**
-   * Maximum number of outstanding bytes {@link FlowController} allows before enforcing flow
-   * control.
-   */
-  @Nullable
-  public abstract Long getMaxOutstandingRequestBytes();
-
-  /**
-   * Minimum number of outstanding elements {@link FlowController} allows before enforcing flow
-   * control.
-   */
-  @Nullable
-  public abstract Long getMinOutstandingElementCount();
-
-  /**
-   * Minimum number of outstanding bytes {@link FlowController} allows before enforcing flow
-   * control.
-   */
-  @Nullable
-  public abstract Long getMinOutstandingRequestBytes();
-
-  /** @see FlowControlSettings#getLimitExceededBehavior() */
-  public abstract LimitExceededBehavior getLimitExceededBehavior();
-
-  public abstract Builder toBuilder();
-
-  public static Builder newBuilder() {
-    return new AutoValue_DynamicFlowControlSettings.Builder()
-        .setLimitExceededBehavior(LimitExceededBehavior.Block);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-
-    public abstract Builder setInitialOutstandingElementCount(Long value);
-
-    public abstract Builder setInitialOutstandingRequestBytes(Long value);
-
-    public abstract Builder setMaxOutstandingElementCount(Long value);
-
-    public abstract Builder setMaxOutstandingRequestBytes(Long value);
-
-    public abstract Builder setMinOutstandingElementCount(Long value);
-
-    public abstract Builder setMinOutstandingRequestBytes(Long value);
-
-    public abstract Builder setLimitExceededBehavior(LimitExceededBehavior value);
-
-    abstract DynamicFlowControlSettings autoBuild();
-
-    public DynamicFlowControlSettings build() {
-      DynamicFlowControlSettings settings = autoBuild();
-
-      verifyElementCountSettings(settings);
-      verifyRequestBytesSettings(settings);
-
-      return settings;
-    }
-
-    private void verifyElementCountSettings(DynamicFlowControlSettings settings) {
-      // If LimitExceededBehavior is Ignore, dynamic flow control is disabled, there's no need to
-      // check element count limit settings
-      if (settings.getLimitExceededBehavior() == LimitExceededBehavior.Ignore) {
-        return;
-      }
-      if (settings.getInitialOutstandingElementCount() == null
-          && settings.getMinOutstandingElementCount() == null
-          && settings.getMaxOutstandingElementCount() == null) {
-        return;
-      }
-      Preconditions.checkState(
-          settings.getInitialOutstandingElementCount() != null
-              && settings.getMinOutstandingElementCount() != null
-              && settings.getMaxOutstandingElementCount() != null,
-          "Throttling on element count is disabled by default. To enable this setting,"
-              + " minOutstandingElementCount, initialOutstandingElementCount, and "
-              + "maxOutstandingElementCount must all be set.");
-      Preconditions.checkState(
-          settings.getMinOutstandingElementCount() > 0
-              && settings.getInitialOutstandingElementCount()
-                  <= settings.getMaxOutstandingElementCount()
-              && settings.getInitialOutstandingElementCount()
-                  >= settings.getMinOutstandingElementCount(),
-          "If throttling on element count is set, minOutstandingElementCount must be"
-              + " greater than 0, and minOutstandingElementCount <= "
-              + "initialOutstandingElementCount <= maxOutstandingElementCount");
-    }
-
-    private void verifyRequestBytesSettings(DynamicFlowControlSettings settings) {
-      // If LimitExceededBehavior is Ignore, dynamic flow control is disabled, there's no need to
-      // check request bytes limit settings
-      if (settings.getLimitExceededBehavior() == LimitExceededBehavior.Ignore) {
-        return;
-      }
-      if (settings.getInitialOutstandingRequestBytes() == null
-          && settings.getMinOutstandingRequestBytes() == null
-          && settings.getMaxOutstandingRequestBytes() == null) {
-        return;
-      }
-      Preconditions.checkState(
-          settings.getInitialOutstandingRequestBytes() != null
-              && settings.getMinOutstandingRequestBytes() != null
-              && settings.getMaxOutstandingRequestBytes() != null,
-          "Throttling on number of bytes is disabled by default. To enable this "
-              + "setting, minOutstandingRequestBytes, initialOutstandingRequestBytes, and "
-              + "maxOutstandingRequestBytes must all be set");
-      Preconditions.checkState(
-          settings.getMinOutstandingRequestBytes() > 0
-              && settings.getInitialOutstandingRequestBytes()
-                  <= settings.getMaxOutstandingRequestBytes()
-              && settings.getInitialOutstandingRequestBytes()
-                  >= settings.getMinOutstandingRequestBytes(),
-          "If throttling on number of bytes is set, minOutstandingRequestBytes must "
-              + "be greater than 0, and minOutstandingRequestBytes <= "
-              + "initialOutstandingRequestBytes <= maxOutstandingRequestBytes");
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/ElementCounter.java b/gax/src/main/java/com/google/api/gax/batching/ElementCounter.java
deleted file mode 100644
index 40c271699..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/ElementCounter.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-/**
- * Interface representing an object that provides a numerical count given an object of the
- * parameterized type.
- */
-public interface ElementCounter<E> {
-  /** Provides the numerical count associated with the given object. */
-  long count(E element);
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/FlowControlEventStats.java b/gax/src/main/java/com/google/api/gax/batching/FlowControlEventStats.java
deleted file mode 100644
index 005b2bced..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/FlowControlEventStats.java
+++ /dev/null
@@ -1,144 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
-
-/**
- * Record the statistics of flow control events.
- *
- * <p>This class is populated by FlowController, which will record throttling events. Currently it
- * only keeps the last flow control event, but it could be expanded to record more information in
- * the future. The events can be used to dynamically adjust concurrency in the client. For example:
- *
- * <pre>{@code
- * // Increase flow control limits if there was throttling in the past 5 minutes and throttled time
- * // was longer than 1 minute.
- * while(true) {
- *    FlowControlEvent event = flowControlEventStats.getLastFlowControlEvent();
- *    if (event != null
- *         && event.getTimestampMs() > System.currentMillis() - TimeUnit.MINUTES.toMillis(5)
- *         && event.getThrottledTimeInMs() > TimeUnit.MINUTES.toMillis(1)) {
- *      flowController.increaseThresholds(elementSteps, byteSteps);
- *    }
- *    Thread.sleep(TimeUnit.MINUTE.toMillis(10));
- * }
- * }</pre>
- */
-@InternalApi("For google-cloud-java client use only")
-public class FlowControlEventStats {
-
-  private volatile FlowControlEvent lastFlowControlEvent;
-
-  // We only need the last event to check if there was throttling in the past X minutes so this
-  // doesn't need to be super accurate.
-  void recordFlowControlEvent(FlowControlEvent event) {
-    if (lastFlowControlEvent == null || event.compareTo(lastFlowControlEvent) > 0) {
-      lastFlowControlEvent = event;
-    }
-  }
-
-  public FlowControlEvent getLastFlowControlEvent() {
-    return lastFlowControlEvent;
-  }
-
-  /**
-   * A flow control event. Record throttled time if {@link LimitExceededBehavior} is {@link
-   * LimitExceededBehavior#Block}, or the exception if the behavior is {@link
-   * LimitExceededBehavior#ThrowException}.
-   */
-  public static class FlowControlEvent implements Comparable<FlowControlEvent> {
-    static FlowControlEvent createReserveDelayed(long throttledTimeInMs) {
-      return createReserveDelayed(System.currentTimeMillis(), throttledTimeInMs);
-    }
-
-    static FlowControlEvent createReserveDenied(FlowControlException exception) {
-      return createReserveDenied(System.currentTimeMillis(), exception);
-    }
-
-    /** Package-private for use in testing. */
-    @VisibleForTesting
-    static FlowControlEvent createReserveDelayed(long timestampMs, long throttledTimeInMs) {
-      Preconditions.checkArgument(timestampMs > 0, "timestamp must be greater than 0");
-      Preconditions.checkArgument(throttledTimeInMs > 0, "throttled time must be greater than 0");
-      return new FlowControlEvent(timestampMs, throttledTimeInMs, null);
-    }
-
-    /** Package-private for use in testing. */
-    @VisibleForTesting
-    static FlowControlEvent createReserveDenied(long timestampMs, FlowControlException exception) {
-      Preconditions.checkArgument(timestampMs > 0, "timestamp must be greater than 0");
-      Preconditions.checkNotNull(
-          exception, "FlowControlException can't be null when reserve is denied");
-      return new FlowControlEvent(timestampMs, null, exception);
-    }
-
-    private long timestampMs;
-    private Long throttledTimeMs;
-    private FlowControlException exception;
-
-    private FlowControlEvent(
-        long timestampMs,
-        @Nullable Long throttledTimeMs,
-        @Nullable FlowControlException exception) {
-      this.timestampMs = timestampMs;
-      this.throttledTimeMs = throttledTimeMs;
-      this.exception = exception;
-    }
-
-    public long getTimestampMs() {
-      return timestampMs;
-    }
-
-    @Nullable
-    public FlowControlException getException() {
-      return exception;
-    }
-
-    @Nullable
-    public Long getThrottledTime(TimeUnit timeUnit) {
-      return throttledTimeMs == null
-          ? null
-          : timeUnit.convert(throttledTimeMs, TimeUnit.MILLISECONDS);
-    }
-
-    @Override
-    public int compareTo(FlowControlEvent otherEvent) {
-      return Long.compare(this.getTimestampMs(), otherEvent.getTimestampMs());
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/FlowControlSettings.java b/gax/src/main/java/com/google/api/gax/batching/FlowControlSettings.java
deleted file mode 100644
index b1634c2f6..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/FlowControlSettings.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.auto.value.AutoValue;
-import com.google.common.base.Preconditions;
-import javax.annotation.Nullable;
-
-/** Settings for {@link FlowController}. */
-@AutoValue
-public abstract class FlowControlSettings {
-  public static FlowControlSettings getDefaultInstance() {
-    return FlowControlSettings.newBuilder().build();
-  }
-
-  /** Maximum number of outstanding elements to keep in memory before enforcing flow control. */
-  @Nullable
-  public abstract Long getMaxOutstandingElementCount();
-
-  /** Maximum number of outstanding bytes to keep in memory before enforcing flow control. */
-  @Nullable
-  public abstract Long getMaxOutstandingRequestBytes();
-
-  /**
-   * The behavior of {@link FlowController} when the specified limits are exceeded. Defaults to
-   * Block.
-   *
-   * <p>The expected behavior for each of these values is:
-   *
-   * <ul>
-   *   <li>ThrowException: the FlowController will throw a {@link FlowControlException} if any of
-   *       the limits are exceeded.
-   *   <li>Block: the reserve() method of FlowController will block until the quote is available to
-   *       be reserved.
-   *   <li>Ignore: all flow control limits will be ignored; the FlowController is disabled.
-   * </ul>
-   */
-  public abstract LimitExceededBehavior getLimitExceededBehavior();
-
-  public abstract Builder toBuilder();
-
-  public static Builder newBuilder() {
-    return new AutoValue_FlowControlSettings.Builder()
-        .setLimitExceededBehavior(LimitExceededBehavior.Block);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setMaxOutstandingElementCount(Long value);
-
-    public abstract Builder setMaxOutstandingRequestBytes(Long value);
-
-    public abstract Builder setLimitExceededBehavior(LimitExceededBehavior value);
-
-    abstract FlowControlSettings autoBuild();
-
-    public FlowControlSettings build() {
-      FlowControlSettings settings = autoBuild();
-      Preconditions.checkArgument(
-          settings.getMaxOutstandingElementCount() == null
-              || settings.getMaxOutstandingElementCount() > 0,
-          "maxOutstandingElementCount limit is disabled by default, but if set it must be set to a value greater than 0.");
-      Preconditions.checkArgument(
-          settings.getMaxOutstandingRequestBytes() == null
-              || settings.getMaxOutstandingRequestBytes() > 0,
-          "maxOutstandingRequestBytes limit is disabled by default, but if set it must be set to a value greater than 0.");
-      return settings;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/FlowController.java b/gax/src/main/java/com/google/api/gax/batching/FlowController.java
deleted file mode 100644
index 00bf6988d..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/FlowController.java
+++ /dev/null
@@ -1,357 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.FlowControlEventStats.FlowControlEvent;
-import com.google.common.base.Preconditions;
-import com.google.common.base.Stopwatch;
-import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
-
-/** Provides flow control capability. */
-public class FlowController {
-  /** Base exception that signals a flow control state. */
-  public abstract static class FlowControlException extends Exception {
-    private FlowControlException() {}
-  }
-
-  /**
-   * Runtime exception that can be used in place of FlowControlException when an unchecked exception
-   * is required.
-   */
-  public static class FlowControlRuntimeException extends RuntimeException {
-    private FlowControlRuntimeException(FlowControlException e) {
-      super(e);
-    }
-
-    public static FlowControlRuntimeException fromFlowControlException(FlowControlException e) {
-      return new FlowControlRuntimeException(e);
-    }
-  }
-
-  /**
-   * Exception thrown when client-side flow control is enforced based on the maximum number of
-   * outstanding in-memory elements.
-   */
-  public static final class MaxOutstandingElementCountReachedException
-      extends FlowControlException {
-    private final long currentMaxElementCount;
-
-    public MaxOutstandingElementCountReachedException(long currentMaxElementCount) {
-      this.currentMaxElementCount = currentMaxElementCount;
-    }
-
-    public long getCurrentMaxBatchElementCount() {
-      return currentMaxElementCount;
-    }
-
-    @Override
-    public String toString() {
-      return String.format(
-          "The maximum number of batch elements: %d have been reached.", currentMaxElementCount);
-    }
-  }
-
-  /**
-   * Exception thrown when client-side flow control is enforced based on the maximum number of
-   * unacknowledged in-memory bytes.
-   */
-  public static final class MaxOutstandingRequestBytesReachedException
-      extends FlowControlException {
-    private final long currentMaxBytes;
-
-    public MaxOutstandingRequestBytesReachedException(long currentMaxBytes) {
-      this.currentMaxBytes = currentMaxBytes;
-    }
-
-    public long getCurrentMaxBatchBytes() {
-      return currentMaxBytes;
-    }
-
-    @Override
-    public String toString() {
-      return String.format(
-          "The maximum number of batch bytes: %d have been reached.", currentMaxBytes);
-    }
-  }
-
-  /**
-   * Enumeration of behaviors that FlowController can use in case the flow control limits are
-   * exceeded.
-   */
-  public enum LimitExceededBehavior {
-    /**
-     * Throws {@link MaxOutstandingElementCountReachedException} or {@link
-     * MaxOutstandingRequestBytesReachedException}.
-     *
-     * <p>This might be appropriate in interactive scenarios. For example, a web server might catch
-     * these exceptions and report to the user that the system is overloaded and that the user could
-     * try again later. It could also be useful in applications that implement custom rate-limiting
-     * logic.
-     */
-    ThrowException,
-
-    /**
-     * Waits until the request can be made without exceeding the limit.
-     *
-     * <p>This might be appropriate in batch-processing, where latencies of individual requests are
-     * not important.
-     */
-    Block,
-
-    /**
-     * Disables flow-control.
-     *
-     * <p>This is provided mainly for debugging and not recommended for production use. Having too
-     * many requests in-flight might cause RPCs to fail due to congested network or the computer to
-     * run out of memory due to excessive buffering, etc.
-     */
-    Ignore,
-  }
-
-  @Nullable private final Semaphore64 outstandingElementCount;
-  @Nullable private final Semaphore64 outstandingByteCount;
-  @Nullable private final Long maxElementCountLimit;
-  @Nullable private final Long maxRequestBytesLimit;
-  @Nullable private final Long minElementCountLimit;
-  @Nullable private final Long minRequestBytesLimit;
-  private final LimitExceededBehavior limitExceededBehavior;
-  private final Object updateLimitLock;
-
-  // Threshold to record throttling events. If reserve() takes longer than this threshold, it will
-  // be recorded as a throttling event.
-  private static final long RESERVE_FLOW_CONTROL_THRESHOLD_MS = 1;
-  private final FlowControlEventStats flowControlEventStats;
-
-  public FlowController(FlowControlSettings settings) {
-    // When the FlowController is initialized with FlowControlSettings, flow control limits can't be
-    // adjusted. min, current, max element count and request bytes are initialized with the max
-    // values in FlowControlSettings.
-    this(convertFlowControlSettings(settings));
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  public FlowController(DynamicFlowControlSettings settings) {
-    this.limitExceededBehavior = settings.getLimitExceededBehavior();
-    this.updateLimitLock = new Object();
-    this.flowControlEventStats = new FlowControlEventStats();
-    switch (settings.getLimitExceededBehavior()) {
-      case ThrowException:
-      case Block:
-        break;
-      case Ignore:
-        this.maxElementCountLimit = null;
-        this.maxRequestBytesLimit = null;
-        this.minElementCountLimit = null;
-        this.minRequestBytesLimit = null;
-
-        this.outstandingElementCount = null;
-        this.outstandingByteCount = null;
-        return;
-      default:
-        throw new IllegalArgumentException(
-            "Unknown LimitBehaviour: " + settings.getLimitExceededBehavior());
-    }
-    this.maxElementCountLimit = settings.getMaxOutstandingElementCount();
-    this.minElementCountLimit = settings.getMinOutstandingElementCount();
-    Long initialElementCountLimit = settings.getInitialOutstandingElementCount();
-    if (initialElementCountLimit == null) {
-      outstandingElementCount = null;
-    } else if (settings.getLimitExceededBehavior() == FlowController.LimitExceededBehavior.Block) {
-      outstandingElementCount = new BlockingSemaphore(initialElementCountLimit);
-    } else {
-      outstandingElementCount = new NonBlockingSemaphore(initialElementCountLimit);
-    }
-
-    this.maxRequestBytesLimit = settings.getMaxOutstandingRequestBytes();
-    this.minRequestBytesLimit = settings.getMinOutstandingRequestBytes();
-    Long initialRequestBytesLimit = settings.getInitialOutstandingRequestBytes();
-    if (initialRequestBytesLimit == null) {
-      outstandingByteCount = null;
-    } else if (settings.getLimitExceededBehavior() == FlowController.LimitExceededBehavior.Block) {
-      outstandingByteCount = new BlockingSemaphore(initialRequestBytesLimit);
-    } else {
-      outstandingByteCount = new NonBlockingSemaphore(initialRequestBytesLimit);
-    }
-  }
-
-  public void reserve(long elements, long bytes) throws FlowControlException {
-    Preconditions.checkArgument(elements >= 0);
-    Preconditions.checkArgument(bytes >= 0);
-
-    Stopwatch stopwatch = Stopwatch.createStarted();
-    if (outstandingElementCount != null) {
-      if (!outstandingElementCount.acquire(elements)) {
-        MaxOutstandingElementCountReachedException exception =
-            new MaxOutstandingElementCountReachedException(
-                outstandingElementCount.getPermitLimit());
-        flowControlEventStats.recordFlowControlEvent(
-            FlowControlEvent.createReserveDenied(exception));
-        throw exception;
-      }
-    }
-
-    // Always allows to send a request even if it is larger than the flow control limit,
-    // if it doesn't then it will deadlock the thread.
-    if (outstandingByteCount != null) {
-      if (!outstandingByteCount.acquirePartial(bytes)) {
-        if (outstandingElementCount != null) {
-          outstandingElementCount.release(elements);
-        }
-        MaxOutstandingRequestBytesReachedException exception =
-            new MaxOutstandingRequestBytesReachedException(outstandingByteCount.getPermitLimit());
-        flowControlEventStats.recordFlowControlEvent(
-            FlowControlEvent.createReserveDenied(exception));
-        throw exception;
-      }
-    }
-    long elapsed = stopwatch.elapsed(TimeUnit.MILLISECONDS);
-    if (elapsed >= RESERVE_FLOW_CONTROL_THRESHOLD_MS) {
-      flowControlEventStats.recordFlowControlEvent(FlowControlEvent.createReserveDelayed(elapsed));
-    }
-  }
-
-  public void release(long elements, long bytes) {
-    Preconditions.checkArgument(elements >= 0);
-    Preconditions.checkArgument(bytes >= 0);
-
-    if (outstandingElementCount != null) {
-      outstandingElementCount.release(elements);
-    }
-    if (outstandingByteCount != null) {
-      outstandingByteCount.release(bytes);
-    }
-  }
-
-  /**
-   * Increase flow control limits to allow extra elementSteps elements and byteSteps request bytes
-   * before enforcing flow control.
-   */
-  @InternalApi("For google-cloud-java client use only")
-  public void increaseThresholds(long elementSteps, long byteSteps) {
-    Preconditions.checkArgument(elementSteps >= 0);
-    Preconditions.checkArgument(byteSteps >= 0);
-    synchronized (updateLimitLock) {
-      if (outstandingElementCount != null) {
-        long actualStep =
-            Math.min(elementSteps, maxElementCountLimit - outstandingElementCount.getPermitLimit());
-        outstandingElementCount.increasePermitLimit(actualStep);
-      }
-
-      if (outstandingByteCount != null) {
-        long actualStep =
-            Math.min(byteSteps, maxRequestBytesLimit - outstandingByteCount.getPermitLimit());
-        outstandingByteCount.increasePermitLimit(actualStep);
-      }
-    }
-  }
-
-  /**
-   * Decrease flow control limits to allow elementSteps fewer elements and byteSteps fewer request
-   * bytes before enforcing flow control.
-   */
-  @InternalApi("For google-cloud-java client use only")
-  public void decreaseThresholds(long elementSteps, long byteSteps) {
-    Preconditions.checkArgument(elementSteps >= 0);
-    Preconditions.checkArgument(byteSteps >= 0);
-    synchronized (updateLimitLock) {
-      if (outstandingElementCount != null) {
-        long actualStep =
-            Math.min(elementSteps, outstandingElementCount.getPermitLimit() - minElementCountLimit);
-        outstandingElementCount.reducePermitLimit(actualStep);
-      }
-
-      if (outstandingByteCount != null) {
-        long actualStep =
-            Math.min(byteSteps, outstandingByteCount.getPermitLimit() - minRequestBytesLimit);
-        outstandingByteCount.reducePermitLimit(actualStep);
-      }
-    }
-  }
-
-  private static DynamicFlowControlSettings convertFlowControlSettings(
-      FlowControlSettings settings) {
-    return DynamicFlowControlSettings.newBuilder()
-        .setInitialOutstandingElementCount(settings.getMaxOutstandingElementCount())
-        .setMinOutstandingElementCount(settings.getMaxOutstandingElementCount())
-        .setMaxOutstandingElementCount(settings.getMaxOutstandingElementCount())
-        .setInitialOutstandingRequestBytes(settings.getMaxOutstandingRequestBytes())
-        .setMinOutstandingRequestBytes(settings.getMaxOutstandingRequestBytes())
-        .setMaxOutstandingRequestBytes(settings.getMaxOutstandingRequestBytes())
-        .setLimitExceededBehavior(settings.getLimitExceededBehavior())
-        .build();
-  }
-
-  LimitExceededBehavior getLimitExceededBehavior() {
-    return limitExceededBehavior;
-  }
-
-  @InternalApi("For internal use by google-cloud-java clients only")
-  @Nullable
-  public Long getMaxElementCountLimit() {
-    return maxElementCountLimit;
-  }
-
-  @InternalApi("For internal use by google-cloud-java clients only")
-  @Nullable
-  public Long getMaxRequestBytesLimit() {
-    return maxRequestBytesLimit;
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  @Nullable
-  public Long getMinElementCountLimit() {
-    return minElementCountLimit;
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  @Nullable
-  public Long getMinRequestBytesLimit() {
-    return minRequestBytesLimit;
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  @Nullable
-  public Long getCurrentElementCountLimit() {
-    return outstandingElementCount == null ? null : outstandingElementCount.getPermitLimit();
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  @Nullable
-  public Long getCurrentRequestBytesLimit() {
-    return outstandingByteCount == null ? null : outstandingByteCount.getPermitLimit();
-  }
-
-  @InternalApi("For google-cloud-java client use only")
-  public FlowControlEventStats getFlowControlEventStats() {
-    return flowControlEventStats;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/NonBlockingSemaphore.java b/gax/src/main/java/com/google/api/gax/batching/NonBlockingSemaphore.java
deleted file mode 100644
index 126d1bb7b..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/NonBlockingSemaphore.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.batching;
-
-import com.google.common.base.Preconditions;
-import java.util.concurrent.atomic.AtomicLong;
-
-/** A {@link Semaphore64} that immediately returns with failure if permits are not available. */
-class NonBlockingSemaphore implements Semaphore64 {
-  private AtomicLong acquiredPermits;
-  private AtomicLong limit;
-
-  private static void checkNotNegative(long l) {
-    Preconditions.checkArgument(l >= 0, "negative permits not allowed: %s", l);
-  }
-
-  NonBlockingSemaphore(long permits) {
-    checkNotNegative(permits);
-    this.acquiredPermits = new AtomicLong(0);
-    this.limit = new AtomicLong(permits);
-  }
-
-  @Override
-  public void release(long permits) {
-    checkNotNegative(permits);
-    while (true) {
-      long old = acquiredPermits.get();
-      // TODO: throw exceptions when the permits overflow
-      long newAcquired = Math.max(0, old - permits);
-      if (acquiredPermits.compareAndSet(old, newAcquired)) {
-        return;
-      }
-    }
-  }
-
-  @Override
-  public boolean acquire(long permits) {
-    checkNotNegative(permits);
-    while (true) {
-      long old = acquiredPermits.get();
-      if (old + permits > limit.get()) {
-        return false;
-      }
-      if (acquiredPermits.compareAndSet(old, old + permits)) {
-        return true;
-      }
-    }
-  }
-
-  @Override
-  public boolean acquirePartial(long permits) {
-    checkNotNegative(permits);
-    // To allow individual oversized requests to be sent, clamp the requested permits to the maximum
-    // limit. This will allow individual large requests to be sent. Please note that this behavior
-    // will result in acquiredPermits going over limit.
-    while (true) {
-      long old = acquiredPermits.get();
-      if (old + permits > limit.get() && old > 0) {
-        return false;
-      }
-      if (acquiredPermits.compareAndSet(old, old + permits)) {
-        return true;
-      }
-    }
-  }
-
-  @Override
-  public void increasePermitLimit(long permits) {
-    checkNotNegative(permits);
-    limit.addAndGet(permits);
-  }
-
-  @Override
-  public void reducePermitLimit(long reduction) {
-    checkNotNegative(reduction);
-
-    while (true) {
-      long oldLimit = limit.get();
-      Preconditions.checkState(oldLimit - reduction > 0, "permit limit underflow");
-      if (limit.compareAndSet(oldLimit, oldLimit - reduction)) {
-        return;
-      }
-    }
-  }
-
-  @Override
-  public long getPermitLimit() {
-    return limit.get();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/NumericThreshold.java b/gax/src/main/java/com/google/api/gax/batching/NumericThreshold.java
deleted file mode 100644
index 3012873ce..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/NumericThreshold.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.common.base.Preconditions;
-
-/** A threshold which accumulates a count based on the provided ElementCounter. */
-public final class NumericThreshold<E> implements BatchingThreshold<E> {
-  private final long threshold;
-  private final ElementCounter<E> extractor;
-  private long sum;
-
-  /**
-   * Constructs a NumericThreshold.
-   *
-   * @param threshold The value that allows an event to happen.
-   * @param extractor Object that extracts a numeric value from the value object.
-   */
-  public NumericThreshold(long threshold, ElementCounter<E> extractor) {
-    this.threshold = threshold;
-    this.extractor = Preconditions.checkNotNull(extractor);
-    this.sum = 0;
-  }
-
-  @Override
-  public void accumulate(E e) {
-    sum += extractor.count(e);
-  }
-
-  @Override
-  public boolean isThresholdReached() {
-    return sum >= threshold;
-  }
-
-  @Override
-  public BatchingThreshold<E> copyWithZeroedValue() {
-    return new NumericThreshold<E>(threshold, extractor);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/PartitionKey.java b/gax/src/main/java/com/google/api/gax/batching/PartitionKey.java
deleted file mode 100644
index ad1ee483a..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/PartitionKey.java
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.batching;
-
-import com.google.common.collect.ImmutableList;
-
-public final class PartitionKey {
-  private final ImmutableList<Object> keys;
-  private final int hash;
-
-  public PartitionKey(Object... keys) {
-    this.keys = ImmutableList.copyOf(keys);
-
-    int hash = 1;
-    for (Object obj : keys) {
-      hash = hash * 31 + obj.hashCode();
-    }
-    this.hash = hash;
-  }
-
-  @Override
-  public int hashCode() {
-    return hash;
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    }
-    if (!(obj instanceof PartitionKey)) {
-      return false;
-    }
-    PartitionKey other = (PartitionKey) obj;
-
-    if (keys.size() != other.keys.size()) {
-      return false;
-    }
-    for (int i = 0; i < keys.size(); i++) {
-      if (!keys.get(i).equals(other.keys.get(i))) {
-        return false;
-      }
-    }
-    return true;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/RequestBuilder.java b/gax/src/main/java/com/google/api/gax/batching/RequestBuilder.java
deleted file mode 100644
index 1371069a8..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/RequestBuilder.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-public interface RequestBuilder<RequestT> {
-  void appendRequest(RequestT request);
-
-  RequestT build();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/Semaphore64.java b/gax/src/main/java/com/google/api/gax/batching/Semaphore64.java
deleted file mode 100644
index f0e751846..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/Semaphore64.java
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-/**
- * Semaphore64 is similar to {@link java.util.concurrent.Semaphore} but allows up to {@code 2^63-1}
- * permits. It also allows adding / reducing permits to the original limit and acquire partial
- * permits.
- *
- * <p>Users who do not need such large number of permits and the extra functionalities are strongly
- * encouraged to use Java's {@code Semaphore} instead. It is almost certainly faster and less error
- * prone.
- */
-interface Semaphore64 {
-  boolean acquire(long permits);
-
-  void release(long permits);
-
-  /**
-   * When try to acquire more permits than what's allowed, acquiring the limit instead of what's
-   * asked.
-   */
-  boolean acquirePartial(long permits);
-
-  void increasePermitLimit(long permits);
-
-  void reducePermitLimit(long reduction);
-
-  long getPermitLimit();
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/ThresholdBatchReceiver.java b/gax/src/main/java/com/google/api/gax/batching/ThresholdBatchReceiver.java
deleted file mode 100644
index 5f655a8b5..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/ThresholdBatchReceiver.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import com.google.api.core.ApiFuture;
-
-/**
- * Interface representing an object that receives batches from a ThresholdBatcher and takes action
- * on them. Implementations of ThresholdBatchReceiver should be thread-safe.
- */
-public interface ThresholdBatchReceiver<BatchT> {
-
-  /**
-   * Validate that the batch can be received by this ThresholdBatchReceiver. This is called to
-   * validate a batch before it is sent to the ThresholdBatcher.
-   */
-  void validateBatch(BatchT message);
-
-  /** Process the given batch asynchronously. */
-  ApiFuture<?> processBatch(BatchT batch);
-}
diff --git a/gax/src/main/java/com/google/api/gax/batching/ThresholdBatcher.java b/gax/src/main/java/com/google/api/gax/batching/ThresholdBatcher.java
deleted file mode 100644
index 75d93ec14..000000000
--- a/gax/src/main/java/com/google/api/gax/batching/ThresholdBatcher.java
+++ /dev/null
@@ -1,281 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.locks.ReentrantLock;
-import org.threeten.bp.Duration;
-
-/**
- * Queues up elements until either a duration of time has passed or any threshold in a given set of
- * thresholds is breached, and then delivers the elements in a batch to the consumer.
- */
-public final class ThresholdBatcher<E> {
-
-  private class ReleaseResourcesFunction<T> implements ApiFunction<T, Void> {
-    private final E batch;
-
-    private ReleaseResourcesFunction(E batch) {
-      this.batch = batch;
-    }
-
-    @Override
-    public Void apply(T input) {
-      flowController.release(batch);
-      return null;
-    }
-  }
-
-  private final Runnable pushCurrentBatchRunnable =
-      new Runnable() {
-        @Override
-        public void run() {
-          pushCurrentBatch();
-        }
-      };
-
-  private final ArrayList<BatchingThreshold<E>> thresholds;
-  private final ScheduledExecutorService executor;
-  private final Duration maxDelay;
-  private final ThresholdBatchReceiver<E> receiver;
-  private final BatchingFlowController<E> flowController;
-  private final BatchMerger<E> batchMerger;
-
-  // Invariant:
-  // - lock gates all accesses to members below
-  // - currentOpenBatch and currentAlarmFuture are either both null or both non-null
-  private final ReentrantLock lock = new ReentrantLock();
-  private E currentOpenBatch;
-  private Future<?> currentAlarmFuture;
-
-  private ThresholdBatcher(Builder<E> builder) {
-    this.thresholds = new ArrayList<>(builder.thresholds);
-    this.executor = Preconditions.checkNotNull(builder.executor);
-    this.maxDelay = Preconditions.checkNotNull(builder.maxDelay);
-    this.receiver = Preconditions.checkNotNull(builder.receiver);
-    this.flowController = Preconditions.checkNotNull(builder.flowController);
-    this.batchMerger = Preconditions.checkNotNull(builder.batchMerger);
-
-    resetThresholds();
-  }
-
-  /** Builder for a ThresholdBatcher. */
-  public static class Builder<E> {
-    private Collection<BatchingThreshold<E>> thresholds;
-    private ScheduledExecutorService executor;
-    private Duration maxDelay;
-    private ThresholdBatchReceiver<E> receiver;
-    private BatchingFlowController<E> flowController;
-    private BatchMerger<E> batchMerger;
-
-    private Builder() {}
-
-    /** Set the executor for the ThresholdBatcher. */
-    public Builder<E> setExecutor(ScheduledExecutorService executor) {
-      this.executor = executor;
-      return this;
-    }
-
-    /** Set the max delay for a batch. This is counted from the first item added to a batch. */
-    public Builder<E> setMaxDelay(Duration maxDelay) {
-      this.maxDelay = maxDelay;
-      return this;
-    }
-
-    /** Set the thresholds for the ThresholdBatcher. */
-    public Builder<E> setThresholds(Collection<BatchingThreshold<E>> thresholds) {
-      this.thresholds = thresholds;
-      return this;
-    }
-
-    /** Set the threshold batch receiver for the ThresholdBatcher. */
-    public Builder<E> setReceiver(ThresholdBatchReceiver<E> receiver) {
-      this.receiver = receiver;
-      return this;
-    }
-
-    /** Set the flow controller for the ThresholdBatcher. */
-    public Builder<E> setFlowController(BatchingFlowController<E> flowController) {
-      this.flowController = flowController;
-      return this;
-    }
-
-    /** Set the batch merger for the ThresholdBatcher. */
-    public Builder<E> setBatchMerger(BatchMerger<E> batchMerger) {
-      this.batchMerger = batchMerger;
-      return this;
-    }
-
-    /** Build the ThresholdBatcher. */
-    public ThresholdBatcher<E> build() {
-      return new ThresholdBatcher<>(this);
-    }
-  }
-
-  /** Get a new builder for a ThresholdBatcher. */
-  public static <E> Builder<E> newBuilder() {
-    return new Builder<>();
-  }
-
-  /**
-   * Adds an element to the batcher. If the element causes the collection to go past any of the
-   * thresholds, the batch will be sent to the {@code ThresholdBatchReceiver}.
-   */
-  public void add(E e) throws FlowControlException {
-    // We need to reserve resources from flowController outside the lock, so that they can be
-    // released by pushCurrentBatch().
-    flowController.reserve(e);
-    lock.lock();
-    try {
-      receiver.validateBatch(e);
-      boolean anyThresholdReached = isAnyThresholdReached(e);
-
-      if (currentOpenBatch == null) {
-        currentOpenBatch = e;
-        // Schedule a job only when no thresholds have been exceeded, otherwise it will be
-        // immediately cancelled
-        if (!anyThresholdReached) {
-          currentAlarmFuture =
-              executor.schedule(
-                  pushCurrentBatchRunnable, maxDelay.toMillis(), TimeUnit.MILLISECONDS);
-        }
-      } else {
-        batchMerger.merge(currentOpenBatch, e);
-      }
-
-      if (anyThresholdReached) {
-        pushCurrentBatch();
-      }
-    } finally {
-      lock.unlock();
-    }
-  }
-
-  /** * Package-private for use in testing. */
-  @VisibleForTesting
-  boolean isEmpty() {
-    lock.lock();
-    try {
-      return currentOpenBatch == null;
-    } finally {
-      lock.unlock();
-    }
-  }
-
-  /**
-   * Push the current batch to the batch receiver. Returns an ApiFuture that completes once the
-   * batch has been processed by the batch receiver and the flow controller resources have been
-   * released.
-   *
-   * <p>Note that this future can complete for the current batch before previous batches have
-   * completed, so it cannot be depended upon for flushing.
-   */
-  @VisibleForTesting
-  public ApiFuture<Void> pushCurrentBatch() {
-    final E batch = removeBatch();
-    if (batch == null) {
-      return ApiFutures.immediateFuture(null);
-    }
-
-    final SettableApiFuture<Void> retFuture = SettableApiFuture.create();
-
-    // It is tempting to use transform to both release and get ApiFuture<Void>.
-    // This is incorrect because we also need to release on failure.
-    //
-    // It is also tempting to transform to get ApiFuture<Void> and addListener
-    // separately to release. This probably works as most users expect,
-    // but makes this class hard to test: retFuture.get() returning
-    // won't guarantee that flow control has been released.
-    ApiFutures.addCallback(
-        receiver.processBatch(batch),
-        new ApiFutureCallback<Object>() {
-          @Override
-          public void onSuccess(Object obj) {
-            flowController.release(batch);
-            retFuture.set(null);
-          }
-
-          @Override
-          public void onFailure(Throwable t) {
-            flowController.release(batch);
-            retFuture.setException(t);
-          }
-        },
-        directExecutor());
-
-    return retFuture;
-  }
-
-  private E removeBatch() {
-    lock.lock();
-    try {
-      E batch = currentOpenBatch;
-      currentOpenBatch = null;
-      if (currentAlarmFuture != null) {
-        currentAlarmFuture.cancel(false);
-        currentAlarmFuture = null;
-      }
-      resetThresholds();
-      return batch;
-    } finally {
-      lock.unlock();
-    }
-  }
-
-  private boolean isAnyThresholdReached(E e) {
-    for (BatchingThreshold<E> threshold : thresholds) {
-      threshold.accumulate(e);
-      if (threshold.isThresholdReached()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  private void resetThresholds() {
-    for (int i = 0; i < thresholds.size(); i++) {
-      thresholds.set(i, thresholds.get(i).copyWithZeroedValue());
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/BackgroundResource.java b/gax/src/main/java/com/google/api/gax/core/BackgroundResource.java
deleted file mode 100644
index e279c2c03..000000000
--- a/gax/src/main/java/com/google/api/gax/core/BackgroundResource.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import java.util.concurrent.TimeUnit;
-
-/**
- * Represents a resource running in the background that needs to be shut down for resources to be
- * released.
- */
-public interface BackgroundResource extends AutoCloseable {
-
-  /**
-   * Initiates an orderly shutdown in which previously submitted work is finished, but no new work
-   * will be accepted. Invocation has no additional effect if already shut down.
-   *
-   * <p>This method does not wait for previously submitted work to complete execution. Use
-   * awaitTermination to do that.
-   */
-  void shutdown();
-
-  /** Returns true if this background resource has been shut down. */
-  boolean isShutdown();
-
-  /**
-   * Returns true if all work has completed following shut down. Note that isTerminated is never
-   * true unless either shutdown or shutdownNow was called first.
-   */
-  boolean isTerminated();
-
-  /**
-   * Attempts to stop all actively executing work and halts the processing of waiting work.
-   *
-   * <p>This method does not wait for actively executing work to terminate. Use awaitTermination to
-   * do that.
-   *
-   * <p>There are no guarantees beyond best-effort attempts to stop processing actively executing
-   * work. For example, typical implementations will cancel via Thread.interrupt(), so any task that
-   * fails to respond to interrupts may never terminate.
-   */
-  void shutdownNow();
-
-  /**
-   * Blocks until all work has completed execution after a shutdown request, or the timeout occurs,
-   * or the current thread is interrupted, whichever happens first.
-   */
-  boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException;
-
-  // NEXT_MAJOR_VER: override close() to remove 'throws Exception'
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/BackgroundResourceAggregation.java b/gax/src/main/java/com/google/api/gax/core/BackgroundResourceAggregation.java
deleted file mode 100644
index d168e6186..000000000
--- a/gax/src/main/java/com/google/api/gax/core/BackgroundResourceAggregation.java
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-/** Treats a collection of background resources as a single background resource. */
-public class BackgroundResourceAggregation implements BackgroundResource {
-
-  private final List<BackgroundResource> resources;
-
-  public BackgroundResourceAggregation(List<BackgroundResource> resources) {
-    this.resources = resources;
-  }
-
-  @Override
-  public void shutdown() {
-    for (BackgroundResource resource : resources) {
-      resource.shutdown();
-    }
-  }
-
-  @Override
-  public boolean isShutdown() {
-    for (BackgroundResource resource : resources) {
-      if (!resource.isShutdown()) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  @Override
-  public boolean isTerminated() {
-    for (BackgroundResource resource : resources) {
-      if (!resource.isTerminated()) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  @Override
-  public void shutdownNow() {
-    for (BackgroundResource resource : resources) {
-      resource.shutdownNow();
-    }
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    for (BackgroundResource resource : resources) {
-      // TODO subtract time already used up from previous resources
-      boolean awaitResult = resource.awaitTermination(duration, unit);
-      if (!awaitResult) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  // NEXT_MAJOR_VER: remove 'throws Exception'
-  @Override
-  public final void close() throws Exception {
-    shutdown();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/BaseBackgroundResource.java b/gax/src/main/java/com/google/api/gax/core/BaseBackgroundResource.java
deleted file mode 100644
index 83c697975..000000000
--- a/gax/src/main/java/com/google/api/gax/core/BaseBackgroundResource.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import java.util.concurrent.TimeUnit;
-
-/** A Background resource that does nothing. */
-public class BaseBackgroundResource implements BackgroundResource {
-
-  @Override
-  public void shutdown() {
-    // no-op
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return false;
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return false;
-  }
-
-  @Override
-  public void shutdownNow() {
-    // no-op
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return false;
-  }
-
-  // NEXT_MAJOR_VER: remove 'throws Exception'
-  @Override
-  public void close() throws Exception {
-    shutdown();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/CredentialsProvider.java b/gax/src/main/java/com/google/api/gax/core/CredentialsProvider.java
deleted file mode 100644
index f1db77004..000000000
--- a/gax/src/main/java/com/google/api/gax/core/CredentialsProvider.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.auth.Credentials;
-import java.io.IOException;
-
-/**
- * Provides an interface to hold and acquire the credentials that will be used to call the service.
- */
-public interface CredentialsProvider {
-  /**
-   * Gets the credentials which will be used to call the service. If the credentials have not been
-   * acquired yet, then they will be acquired when this function is called.
-   */
-  Credentials getCredentials() throws IOException;
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/Distribution.java b/gax/src/main/java/com/google/api/gax/core/Distribution.java
deleted file mode 100644
index 71d17c549..000000000
--- a/gax/src/main/java/com/google/api/gax/core/Distribution.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicLongArray;
-
-/**
- * Distribution records values from {@code 0} (inclusive) to {@code endValue} (exclusive) and
- * computes their percentiles.
- *
- * <p>Methods may be called concurrently.
- */
-public class Distribution {
-
-  private final AtomicLongArray buckets;
-  private final AtomicInteger count = new AtomicInteger(0);
-
-  public Distribution(int endValue) {
-    Preconditions.checkArgument(endValue > 0);
-    buckets = new AtomicLongArray(endValue);
-  }
-
-  // TODO(pongad): remove this when google-cloud-java no longer calls it.
-  @Deprecated
-  public long getNthPercentile(double percentile) {
-    return getPercentile(percentile);
-  }
-
-  /**
-   * Get the percentile of recorded values. If called concurrently with {@link #record(int)}, the
-   * result is an approximate.
-   */
-  public int getPercentile(double percentile) {
-    // NOTE: This implementation uses the nearest-rank method.
-    // https://en.wikipedia.org/wiki/Percentile#The_nearest-rank_method
-    //
-    // If called concurrently with record, this implementation biases low.
-    // Since we read count before iterating the array, more elements might have been recorded
-    // and we might not iterate far enough to be fair.
-    // Still, this probably won't matter greatly in practice.
-
-    Preconditions.checkArgument(percentile > 0.0);
-    Preconditions.checkArgument(percentile <= 100.0);
-
-    long targetRank = (long) Math.ceil(percentile * count.get() / 100);
-    long rank = 0;
-    for (int i = 0; i < buckets.length(); i++) {
-      rank += buckets.get(i);
-      if (rank >= targetRank) {
-        return i;
-      }
-    }
-    return buckets.length();
-  }
-
-  /**
-   * Records a new value.
-   *
-   * <p>The value must not be negative. To help with distributions with long tails, if the given
-   * value is greater than or equal to {@code endValue}, the value {@code endValue-1} is recorded
-   * instead.
-   */
-  public void record(int value) {
-    Preconditions.checkArgument(value >= 0);
-    if (value >= buckets.length()) {
-      value = buckets.length() - 1;
-    }
-    buckets.incrementAndGet(value);
-    count.incrementAndGet();
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("endValue", buckets.length())
-        .add("count", count.get())
-        .toString();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/ExecutorAsBackgroundResource.java b/gax/src/main/java/com/google/api/gax/core/ExecutorAsBackgroundResource.java
deleted file mode 100644
index 4c67eec16..000000000
--- a/gax/src/main/java/com/google/api/gax/core/ExecutorAsBackgroundResource.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.common.base.Preconditions;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.TimeUnit;
-
-/**
- * ExecutorAsBackgroundResource wraps an {@link ExecutorService} so that it can be used as a {@link
- * BackgroundResource}.
- */
-public class ExecutorAsBackgroundResource implements BackgroundResource {
-
-  private final ExecutorService executor;
-
-  public ExecutorAsBackgroundResource(ExecutorService executor) {
-    this.executor = Preconditions.checkNotNull(executor);
-  }
-
-  @Override
-  public void shutdown() {
-    executor.shutdown();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return executor.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return executor.isTerminated();
-  }
-
-  @Override
-  public void shutdownNow() {
-    executor.shutdownNow();
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return executor.awaitTermination(duration, unit);
-  }
-
-  // NEXT_MAJOR_VER: remove 'throws Exception'
-  @Override
-  public void close() throws Exception {
-    shutdown();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/ExecutorProvider.java b/gax/src/main/java/com/google/api/gax/core/ExecutorProvider.java
deleted file mode 100644
index ae8336036..000000000
--- a/gax/src/main/java/com/google/api/gax/core/ExecutorProvider.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import java.util.concurrent.ScheduledExecutorService;
-
-/**
- * Provides an interface to either build a ScheduledExecutorService or provide a fixed
- * ScheduledExecutorService that will be used to make calls to a service.
- */
-public interface ExecutorProvider {
-  /** Indicates whether the executor should be closed by the containing client class. */
-  boolean shouldAutoClose();
-
-  /** Gets the executor to use. */
-  ScheduledExecutorService getExecutor();
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/FixedCredentialsProvider.java b/gax/src/main/java/com/google/api/gax/core/FixedCredentialsProvider.java
deleted file mode 100644
index e95e11304..000000000
--- a/gax/src/main/java/com/google/api/gax/core/FixedCredentialsProvider.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.auth.Credentials;
-import com.google.auto.value.AutoValue;
-import javax.annotation.Nullable;
-
-/** FixedCredentialsProvider is a CredentialsProvider which always provides the same credentials. */
-@AutoValue
-public abstract class FixedCredentialsProvider implements CredentialsProvider {
-
-  @Override
-  @Nullable
-  public abstract Credentials getCredentials();
-
-  /** Creates a FixedCredentialsProvider. */
-  public static FixedCredentialsProvider create(Credentials credentials) {
-    return new AutoValue_FixedCredentialsProvider(credentials);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/FixedExecutorProvider.java b/gax/src/main/java/com/google/api/gax/core/FixedExecutorProvider.java
deleted file mode 100644
index b06ecbd53..000000000
--- a/gax/src/main/java/com/google/api/gax/core/FixedExecutorProvider.java
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import java.util.concurrent.ScheduledExecutorService;
-
-/** FixedExecutorProvider is an ExecutorProvider which always returns the same executor. */
-public final class FixedExecutorProvider implements ExecutorProvider {
-
-  private final ScheduledExecutorService executor;
-
-  private FixedExecutorProvider(ScheduledExecutorService executor) {
-    this.executor = executor;
-  }
-
-  @Override
-  public ScheduledExecutorService getExecutor() {
-    return executor;
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return false;
-  }
-
-  /** Creates a FixedExecutorProvider. */
-  public static FixedExecutorProvider create(ScheduledExecutorService executor) {
-    return new FixedExecutorProvider(executor);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/GaxProperties.java b/gax/src/main/java/com/google/api/gax/core/GaxProperties.java
deleted file mode 100644
index 483cbe9c8..000000000
--- a/gax/src/main/java/com/google/api/gax/core/GaxProperties.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import static org.graalvm.nativeimage.ImageInfo.PROPERTY_IMAGE_CODE_KEY;
-import static org.graalvm.nativeimage.ImageInfo.PROPERTY_IMAGE_CODE_VALUE_RUNTIME;
-
-import com.google.api.core.InternalApi;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.Properties;
-
-/** Provides properties of the GAX library. */
-@InternalApi
-public class GaxProperties {
-
-  private static final String DEFAULT_VERSION = "";
-  private static final String GAX_VERSION = getLibraryVersion(GaxProperties.class, "version.gax");
-  private static final String JAVA_VERSION = getRuntimeVersion();
-
-  private GaxProperties() {}
-
-  /** Returns the version of the library that the {@code libraryClass} belongs to */
-  public static String getLibraryVersion(Class<?> libraryClass) {
-    String version = libraryClass.getPackage().getImplementationVersion();
-    return version != null ? version : DEFAULT_VERSION;
-  }
-
-  /**
-   * Returns the version of the library that the {@code libraryClass} belongs to, or a property
-   * value in dependencies.properties resource file instead, if the version was not found. The
-   * method is doing I/O operations and is potentially inefficient, the values returned by this
-   * method are expected to be cached.
-   */
-  public static String getLibraryVersion(Class<?> libraryClass, String propertyName) {
-    String version = null;
-    // Always read GaxProperties' version from the properties file.
-    if (!libraryClass.equals(GaxProperties.class)) {
-      version = getLibraryVersion(libraryClass);
-      if (!DEFAULT_VERSION.equals(version)) {
-        return version;
-      }
-    }
-
-    try (InputStream in = libraryClass.getResourceAsStream("/dependencies.properties")) {
-      if (in != null) {
-        Properties props = new Properties();
-        props.load(in);
-        version = props.getProperty(propertyName);
-      }
-    } catch (IOException e) {
-      // ignore
-    }
-
-    return version != null ? version : DEFAULT_VERSION;
-  }
-
-  /** Returns the version of the running JVM */
-  public static String getJavaVersion() {
-    // When running the application as a native image, append `-graalvm` to the
-    // version.
-    String imageCode = System.getProperty(PROPERTY_IMAGE_CODE_KEY);
-    if (imageCode != null && imageCode.equals(PROPERTY_IMAGE_CODE_VALUE_RUNTIME)) {
-      return System.getProperty("java.version") + "-graalvm";
-    }
-    return JAVA_VERSION;
-  }
-
-  /** Returns the current version of GAX. */
-  public static String getGaxVersion() {
-    return GAX_VERSION;
-  }
-
-  /** Returns the current runtime version */
-  private static String getRuntimeVersion() {
-    return System.getProperty("java.version");
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/GoogleCredentialsProvider.java b/gax/src/main/java/com/google/api/gax/core/GoogleCredentialsProvider.java
deleted file mode 100644
index 56642ecde..000000000
--- a/gax/src/main/java/com/google/api/gax/core/GoogleCredentialsProvider.java
+++ /dev/null
@@ -1,164 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.api.core.BetaApi;
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.GoogleCredentials;
-import com.google.auth.oauth2.ServiceAccountCredentials;
-import com.google.auth.oauth2.ServiceAccountJwtAccessCredentials;
-import com.google.auto.value.AutoValue;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.ImmutableList;
-import java.io.IOException;
-import java.util.List;
-import javax.annotation.Nullable;
-
-/**
- * GoogleCredentialsProvider acquires credentials using Application Default Credentials.
- *
- * <p>For more information on Application Default Credentials, see <a
- * href="https://developers.google.com/identity/protocols/application-default-credentials">
- * https://developers.google.com/identity/protocols/application-default-credentials</a>.
- */
-@AutoValue
-public abstract class GoogleCredentialsProvider implements CredentialsProvider {
-
-  public abstract List<String> getScopesToApply();
-
-  @BetaApi
-  public abstract List<String> getJwtEnabledScopes();
-
-  @BetaApi
-  public abstract boolean getUseJwtAccessWithScope();
-
-  @VisibleForTesting
-  @Nullable
-  abstract GoogleCredentials getOAuth2Credentials();
-
-  @Override
-  public Credentials getCredentials() throws IOException {
-    GoogleCredentials credentials = getOAuth2Credentials();
-    if (credentials == null) {
-      credentials = GoogleCredentials.getApplicationDefault();
-    }
-
-    // Check if the current scopes permit JWT token use
-    boolean hasJwtEnabledScope = false;
-    for (String scope : getJwtEnabledScopes()) {
-      if (getScopesToApply().contains(scope)) {
-        hasJwtEnabledScope = true;
-        break;
-      }
-    }
-    // Use JWT tokens when using a service account with an appropriate scope.
-    if (credentials instanceof ServiceAccountCredentials && hasJwtEnabledScope) {
-      ServiceAccountCredentials serviceAccount = (ServiceAccountCredentials) credentials;
-
-      return ServiceAccountJwtAccessCredentials.newBuilder()
-          .setClientEmail(serviceAccount.getClientEmail())
-          .setClientId(serviceAccount.getClientId())
-          .setPrivateKey(serviceAccount.getPrivateKey())
-          .setPrivateKeyId(serviceAccount.getPrivateKeyId())
-          .setQuotaProjectId(serviceAccount.getQuotaProjectId())
-          .build();
-    }
-
-    if (credentials.createScopedRequired()) {
-      credentials = credentials.createScoped(getScopesToApply());
-    }
-
-    if (getUseJwtAccessWithScope() && credentials instanceof ServiceAccountCredentials) {
-      // See https://google.aip.dev/auth/4111 for self signed JWT.
-      ServiceAccountCredentials serviceAccount = (ServiceAccountCredentials) credentials;
-      return serviceAccount.createWithUseJwtAccessWithScope(true);
-    }
-    return credentials;
-  }
-
-  public static Builder newBuilder() {
-    return new AutoValue_GoogleCredentialsProvider.Builder()
-        .setJwtEnabledScopes(ImmutableList.<String>of())
-        .setUseJwtAccessWithScope(false);
-  }
-
-  public abstract Builder toBuilder();
-
-  @BetaApi
-  @AutoValue.Builder
-  public abstract static class Builder {
-
-    /**
-     * Sets the scopes to apply to the credentials that are acquired from Application Default
-     * Credentials, before the credentials are sent to the service.
-     */
-    public abstract Builder setScopesToApply(List<String> val);
-
-    /** The scopes previously provided. */
-    public abstract List<String> getScopesToApply();
-
-    @VisibleForTesting
-    abstract Builder setOAuth2Credentials(GoogleCredentials oauth2Credentials);
-
-    /**
-     * Sets the scopes that are compatible with JWT tokens.
-     *
-     * <p>JWT Tokens don't support scopes, they only support audiences. Audiences allow access to
-     * the entire service as opposed some subset (ie. access can't be restricted to use the scope
-     * {@code https://www.googleapis.com/auth/bigtable.data.readonly}). A service client can opt-in
-     * to using JWT tokens by specifying which scopes encompass the entire service. If any of those
-     * scopes are present when the client is using {@link ServiceAccountCredentials}, then JWT
-     * tokens will be used for authentication.
-     */
-    @BetaApi
-    public abstract Builder setJwtEnabledScopes(List<String> val);
-
-    /** The JWT enable scopes previously provided. */
-    @BetaApi
-    public abstract List<String> getJwtEnabledScopes();
-
-    /** Whether self signed JWT with scopes should be used for service account credentials. */
-    @BetaApi
-    public abstract Builder setUseJwtAccessWithScope(boolean val);
-
-    /** The UseJwtAccessWithScope value previously provided. */
-    @BetaApi
-    public abstract boolean getUseJwtAccessWithScope();
-
-    public GoogleCredentialsProvider build() {
-      setScopesToApply(ImmutableList.copyOf(getScopesToApply()));
-      setJwtEnabledScopes(ImmutableList.copyOf(getJwtEnabledScopes()));
-      setUseJwtAccessWithScope(getUseJwtAccessWithScope());
-      return autoBuild();
-    }
-
-    abstract GoogleCredentialsProvider autoBuild();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/InstantiatingExecutorProvider.java b/gax/src/main/java/com/google/api/gax/core/InstantiatingExecutorProvider.java
deleted file mode 100644
index c91b044cb..000000000
--- a/gax/src/main/java/com/google/api/gax/core/InstantiatingExecutorProvider.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.auto.value.AutoValue;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import java.util.concurrent.ThreadFactory;
-import java.util.concurrent.atomic.AtomicInteger;
-
-/**
- * InstantiatingChannelProvider is an ExecutorProvider which constructs a new
- * ScheduledExecutorService every time getExecutor() is called.
- */
-@AutoValue
-public abstract class InstantiatingExecutorProvider implements ExecutorProvider {
-  // Thread factory to use to create our worker threads
-  private static final ThreadFactory DEFAULT_THREAD_FACTORY =
-      new ThreadFactory() {
-        private final AtomicInteger threadCount = new AtomicInteger();
-
-        @Override
-        public Thread newThread(Runnable runnable) {
-          Thread thread = new Thread(runnable);
-          thread.setName("Gax-" + threadCount.incrementAndGet());
-          thread.setDaemon(true);
-          return thread;
-        }
-      };
-
-  // Package-private constructor prevents others from subclassing.
-  InstantiatingExecutorProvider() {}
-
-  @Override
-  public ScheduledExecutorService getExecutor() {
-    return new ScheduledThreadPoolExecutor(getExecutorThreadCount(), getThreadFactory());
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return true;
-  }
-
-  /** The number of threads used by the executor created by this ExecutorProvider. */
-  public abstract int getExecutorThreadCount();
-
-  /** Return a thread-factory to create gax processing threads so we can name them appropriately */
-  public abstract ThreadFactory getThreadFactory();
-
-  public abstract Builder toBuilder();
-
-  public static Builder newBuilder() {
-    int numCpus = Runtime.getRuntime().availableProcessors();
-    int numThreads = Math.max(4, numCpus);
-
-    return new AutoValue_InstantiatingExecutorProvider.Builder()
-        .setExecutorThreadCount(numThreads)
-        .setThreadFactory(DEFAULT_THREAD_FACTORY);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setExecutorThreadCount(int value);
-
-    public abstract int getExecutorThreadCount();
-
-    public abstract Builder setThreadFactory(ThreadFactory value);
-
-    public abstract ThreadFactory getThreadFactory();
-
-    public abstract InstantiatingExecutorProvider build();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/NoCredentialsProvider.java b/gax/src/main/java/com/google/api/gax/core/NoCredentialsProvider.java
deleted file mode 100644
index 2817f363d..000000000
--- a/gax/src/main/java/com/google/api/gax/core/NoCredentialsProvider.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.auth.Credentials;
-
-/** NoCredentialsProvider is a CredentialsProvider which always returns null. */
-public final class NoCredentialsProvider implements CredentialsProvider {
-  @Override
-  public Credentials getCredentials() {
-    return null;
-  }
-
-  public static NoCredentialsProvider create() {
-    return new NoCredentialsProvider();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/core/ResourceCloseException.java b/gax/src/main/java/com/google/api/gax/core/ResourceCloseException.java
deleted file mode 100644
index 5ed9ca885..000000000
--- a/gax/src/main/java/com/google/api/gax/core/ResourceCloseException.java
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-/** An exception occurs when some background resource is not able to close properly. */
-public class ResourceCloseException extends RuntimeException {
-
-  private static final long serialVersionUID = -283748743873637484L;
-
-  public ResourceCloseException(Exception exception) {
-    super(exception);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationFuture.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationFuture.java
deleted file mode 100644
index 7c15ff9e4..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationFuture.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.retrying.RetryingFuture;
-import java.util.concurrent.ExecutionException;
-
-/**
- * An ApiFuture which tracks polling of a service. The polling is done periodically, based on the
- * {@link com.google.api.gax.retrying.TimedRetryAlgorithm}.
- *
- * <p>Implementations are expected to be thread-safe.
- */
-public interface OperationFuture<ResponseT, MetadataT> extends ApiFuture<ResponseT> {
-  /**
-   * Returns the value of the name of the operation from the initial operation object returned from
-   * the initial call to start the operation. Blocks if the initial call to start the operation
-   * hasn't returned yet.
-   */
-  String getName() throws InterruptedException, ExecutionException;
-
-  /**
-   * Returns the {@link OperationSnapshot} future of the initial request which started this {@code
-   * OperationFuture}.
-   */
-  ApiFuture<OperationSnapshot> getInitialFuture();
-
-  /** Returns the {@link RetryingFuture} which continues to poll {@link OperationSnapshot}. */
-  RetryingFuture<OperationSnapshot> getPollingFuture();
-
-  /**
-   * Peeks at the metadata of the operation tracked by this {@link OperationFuture}. If the initial
-   * future hasn't completed yet this method returns {@code null}, otherwise it returns the latest
-   * metadata returned from the server (i.e. either initial call metadata or the metadata received
-   * from the latest completed poll iteration).
-   *
-   * <p>If not {@code null}, the returned result is guaranteed to be an already completed future, so
-   * {@link ApiFuture#isDone()} will always be {@code true} and {@link ApiFuture#get()} will always
-   * be non-blocking.
-   *
-   * <p>Note, some APIs may return {@code null} in metadata response message. In such cases this
-   * method may return a non-null future whose {@code get()} method will return {@code null}. This
-   * behavior is API specific an should be considered a valid case, which indicates that the recent
-   * poll request has completed, but no specific metadata was provided by the server (i.e. most
-   * probably providing metadata for an intermediate result is not supported by the server).
-   *
-   * <p>This method should be used to check operation progress without blocking current thread.
-   * Since this method returns metadata from the latest completed poll, it is potentially slightly
-   * stale compared to the most recent data. To get the most recent data and/or get notified when
-   * the current scheduled poll request completes use the {@link #getMetadata()} method instead.
-   *
-   * <p>If this operation future is completed, this method always returns the metadata from the last
-   * poll request (which completed the operation future).
-   *
-   * <p>If this operation future failed, this method may (depending on the failure type) return a
-   * non-failing future, representing the metadata from the last poll request (which failed the
-   * operation future).
-   *
-   * <p>If this operation future was cancelled, this method returns a canceled metatata future as
-   * well.
-   *
-   * <p>In general this method behaves similarly to {@link RetryingFuture#peekAttemptResult()}.
-   */
-  ApiFuture<MetadataT> peekMetadata();
-
-  /**
-   * Gets the metadata of the operation tracked by this {@link OperationFuture}. This method returns
-   * the current poll metadata result (or the initial call metadata if it hasn't completed yet). The
-   * returned future completes once the current scheduled poll request (or the initial request if it
-   * hasn't completed yet) is executed and response is received from the server. The time when the
-   * polling request is executed is determined by the underlying polling algorithm.
-   *
-   * <p>Adding direct executor (same thread) callbacks to the future returned by this method is
-   * strongly not recommended, since the future is resolved under retrying future's internal lock
-   * and may affect the operation polling process. Adding separate thread callbacks is ok.
-   *
-   * <p>Note, some APIs may return {@code null} in metadata response message. In such cases this
-   * method may return a non-null future whose {@code get()} method will return {@code null}. This
-   * behavior is API specific an should be considered a valid case, which indicates that the recent
-   * poll request has completed, but no specific metadata was provided by the server. (i.e. most
-   * probably providing metadata for an intermediate result is not supported by the server).
-   *
-   * <p>In most cases this method returns a future which is not completed yet, so calling {@link
-   * ApiFuture#get()} is a potentially blocking operation. To get metadata without blocking the
-   * current thread use the {@link #peekMetadata()} method instead.
-   *
-   * <p>If this operation future is completed, this method always returns the metadata from the last
-   * poll request (which completed the operation future).
-   *
-   * <p>If this operation future failed, this method may (depending on the failure type) return a
-   * non-failing future, representing the metadata from the last poll request (which failed the
-   * operation future).
-   *
-   * <p>If this operation future was cancelled, this method returns a canceled metatata future as
-   * well.
-   *
-   * <p>In general this method behaves similarly to {@link RetryingFuture#getAttemptResult()}.
-   */
-  ApiFuture<MetadataT> getMetadata();
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationFutureImpl.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationFutureImpl.java
deleted file mode 100644
index 769ec2adc..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationFutureImpl.java
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.retrying.RetryingFuture;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-/**
- * An ApiFuture which tracks polling of a service. The polling is done periodically, based on the
- * {@link com.google.api.gax.retrying.TimedRetryAlgorithm}.
- *
- * <p>This class is thread-safe.
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi
-public final class OperationFutureImpl<ResponseT, MetadataT>
-    implements OperationFuture<ResponseT, MetadataT> {
-  private final Object lock = new Object();
-
-  private final RetryingFuture<OperationSnapshot> pollingFuture;
-  private final ApiFuture<OperationSnapshot> initialFuture;
-  private final ApiFuture<ResponseT> resultFuture;
-  private final ApiFunction<OperationSnapshot, MetadataT> metadataTransformer;
-
-  private volatile ApiFuture<OperationSnapshot> peekedAttemptResult;
-  private volatile ApiFuture<MetadataT> peekedPollResult;
-  private volatile ApiFuture<OperationSnapshot> gottenAttemptResult;
-  private volatile ApiFuture<MetadataT> gottenPollResult;
-
-  /**
-   * Creates a new operation future instance.
-   *
-   * @param pollingFuture retrying future which tracks polling of the server operation (in most
-   *     cases with exponential upper bounded intervals)
-   * @param initialFuture the initial future which started the operation on the server side
-   */
-  public OperationFutureImpl(
-      RetryingFuture<OperationSnapshot> pollingFuture,
-      ApiFuture<OperationSnapshot> initialFuture,
-      ApiFunction<OperationSnapshot, ResponseT> responseTransformer,
-      ApiFunction<OperationSnapshot, MetadataT> metadataTransformer) {
-    this.pollingFuture = checkNotNull(pollingFuture);
-    this.initialFuture = checkNotNull(initialFuture);
-    this.resultFuture = ApiFutures.transform(pollingFuture, responseTransformer, directExecutor());
-    this.metadataTransformer = checkNotNull(metadataTransformer);
-  }
-
-  public OperationFutureImpl(
-      RetryingFuture<OperationSnapshot> pollingFuture,
-      ApiFuture<OperationSnapshot> initialFuture,
-      ApiFunction<OperationSnapshot, ResponseT> responseTransformer,
-      ApiFunction<OperationSnapshot, MetadataT> metadataTransformer,
-      ApiFunction<Exception, ResponseT> exceptionTransformer) {
-    this.pollingFuture = checkNotNull(pollingFuture);
-    this.initialFuture = checkNotNull(initialFuture);
-    this.resultFuture =
-        ApiFutures.catching(
-            ApiFutures.transform(pollingFuture, responseTransformer, directExecutor()),
-            Exception.class,
-            exceptionTransformer,
-            directExecutor());
-    this.metadataTransformer = checkNotNull(metadataTransformer);
-  }
-
-  @Override
-  public void addListener(Runnable listener, Executor executor) {
-    pollingFuture.addListener(listener, executor);
-  }
-
-  @Override
-  public boolean cancel(boolean mayInterruptIfRunning) {
-    return pollingFuture.cancel(mayInterruptIfRunning);
-  }
-
-  @Override
-  public boolean isCancelled() {
-    return pollingFuture.isCancelled();
-  }
-
-  @Override
-  public boolean isDone() {
-    return pollingFuture.isDone();
-  }
-
-  @Override
-  public ResponseT get() throws InterruptedException, ExecutionException {
-    return resultFuture.get();
-  }
-
-  @Override
-  public ResponseT get(long timeout, TimeUnit unit)
-      throws InterruptedException, ExecutionException, TimeoutException {
-    return resultFuture.get(timeout, unit);
-  }
-
-  @Override
-  public String getName() throws ExecutionException, InterruptedException {
-    return initialFuture.get().getName();
-  }
-
-  @Override
-  public ApiFuture<OperationSnapshot> getInitialFuture() {
-    return initialFuture;
-  }
-
-  @Override
-  public RetryingFuture<OperationSnapshot> getPollingFuture() {
-    return pollingFuture;
-  }
-
-  // Note, the following two methods are not duplicates of each other even though code checking
-  // tools may indicate so. They assign multiple different class fields.
-  @Override
-  public ApiFuture<MetadataT> peekMetadata() {
-    ApiFuture<OperationSnapshot> future = pollingFuture.peekAttemptResult();
-    synchronized (lock) {
-      if (peekedAttemptResult == future) {
-        return peekedPollResult;
-      }
-      peekedAttemptResult = future;
-      peekedPollResult =
-          ApiFutures.transform(peekedAttemptResult, metadataTransformer, directExecutor());
-      return peekedPollResult;
-    }
-  }
-
-  @Override
-  public ApiFuture<MetadataT> getMetadata() {
-    ApiFuture<OperationSnapshot> future = pollingFuture.getAttemptResult();
-    synchronized (lock) {
-      if (gottenAttemptResult == future) {
-        return gottenPollResult;
-      }
-      gottenAttemptResult = future;
-      gottenPollResult =
-          ApiFutures.transform(gottenAttemptResult, metadataTransformer, directExecutor());
-      return gottenPollResult;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationFutures.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationFutures.java
deleted file mode 100644
index 16d167bd3..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationFutures.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.TimeUnit;
-
-public class OperationFutures {
-  private OperationFutures() {
-    // Utility class
-  }
-
-  /**
-   * Creates an already-completed {@code OperationFuture}, useful for testing.
-   *
-   * <p>{@code completedSnapshot.isDone()} must return true. The snapshot's {@code getResponse()}
-   * and {@code getMetadata()} must be instances of {@code ResponseT} and {@code MetadataT},
-   * respectively.
-   */
-  @SuppressWarnings("unchecked")
-  public static final <ResponseT, MetadataT>
-      OperationFuture<ResponseT, MetadataT> immediateOperationFuture(
-          final OperationSnapshot completedSnapshot) {
-
-    Preconditions.checkArgument(
-        completedSnapshot.isDone(), "given snapshot must already be completed");
-    final ApiFuture<MetadataT> metadataFuture =
-        ApiFutures.immediateFuture((MetadataT) completedSnapshot.getMetadata());
-    final ApiFuture<OperationSnapshot> initialFuture =
-        ApiFutures.immediateFuture(completedSnapshot);
-
-    return new OperationFuture<ResponseT, MetadataT>() {
-      @Override
-      public String getName() {
-        return completedSnapshot.getName();
-      }
-
-      @Override
-      public ApiFuture<MetadataT> getMetadata() {
-        return metadataFuture;
-      }
-
-      @Override
-      public ApiFuture<MetadataT> peekMetadata() {
-        return metadataFuture;
-      }
-
-      @Override
-      public ApiFuture<OperationSnapshot> getInitialFuture() {
-        return initialFuture;
-      }
-
-      @Override
-      public RetryingFuture<OperationSnapshot> getPollingFuture() {
-        throw new UnsupportedOperationException("Not implemented: getPollingFuture().");
-      }
-
-      @Override
-      public void addListener(Runnable runnable, Executor executor) {
-        initialFuture.addListener(runnable, executor);
-      }
-
-      @Override
-      public ResponseT get(long time, TimeUnit unit) throws ExecutionException {
-        return get();
-      }
-
-      @Override
-      public ResponseT get() throws ExecutionException {
-        if (completedSnapshot.getErrorCode().getCode().equals(StatusCode.Code.OK)) {
-          return (ResponseT) completedSnapshot.getResponse();
-        }
-        throw new ExecutionException(
-            new ApiException(null, completedSnapshot.getErrorCode(), false));
-      }
-
-      @Override
-      public boolean isDone() {
-        return true;
-      }
-
-      @Override
-      public boolean isCancelled() {
-        return false;
-      }
-
-      @Override
-      public boolean cancel(boolean b) {
-        return false;
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationResponsePollAlgorithm.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationResponsePollAlgorithm.java
deleted file mode 100644
index 00c3389bb..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationResponsePollAlgorithm.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import com.google.api.gax.retrying.ResultRetryAlgorithm;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-
-/**
- * Operation polling algorithm, which keeps retrying until {@link OperationSnapshot#isDone()} is
- * true.
- */
-public class OperationResponsePollAlgorithm implements ResultRetryAlgorithm<OperationSnapshot> {
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      Throwable prevThrowable, OperationSnapshot prevResponse, TimedAttemptSettings prevSettings) {
-    return null;
-  }
-
-  @Override
-  public boolean shouldRetry(Throwable prevThrowable, OperationSnapshot prevResponse) {
-    return prevThrowable == null && prevResponse != null && !prevResponse.isDone();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationSnapshot.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationSnapshot.java
deleted file mode 100644
index 7f275970e..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationSnapshot.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import com.google.api.gax.rpc.StatusCode;
-
-/**
- * A snapshot of a long-running operation.
- *
- * <p>The metadata and response will have a structure defined by the particular long-running
- * operation that was initiated.
- */
-public interface OperationSnapshot {
-
-  /** The name of the operation. This is used for identifying the operation on the server. */
-  String getName();
-
-  /** Get metadata for the operation, which can change over the course of the operation. */
-  Object getMetadata();
-
-  /** Returns true if the operation is complete or failed, false otherwise. */
-  boolean isDone();
-
-  /**
-   * If the operation is done and successful, returns the response; if the operation is not done or
-   * if it is failed, returns null.
-   */
-  Object getResponse();
-
-  /**
-   * If the operation is done and it failed, returns the failure status code; if the operation is
-   * not done or if it succeeded, returns null.
-   */
-  StatusCode getErrorCode();
-
-  /**
-   * If the operation is done and it failed, returns the error message; if the operation is not done
-   * or if it succeeded, returns null.
-   */
-  String getErrorMessage();
-}
diff --git a/gax/src/main/java/com/google/api/gax/longrunning/OperationTimedPollAlgorithm.java b/gax/src/main/java/com/google/api/gax/longrunning/OperationTimedPollAlgorithm.java
deleted file mode 100644
index ddc49f3c0..000000000
--- a/gax/src/main/java/com/google/api/gax/longrunning/OperationTimedPollAlgorithm.java
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.retrying.ExponentialRetryAlgorithm;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import java.util.concurrent.CancellationException;
-
-/**
- * Operation timed polling algorithm, which uses exponential backoff factor for determining when the
- * next polling operation should be executed. If the polling exceeds the total timeout this
- * algorithm cancels polling.
- */
-public class OperationTimedPollAlgorithm extends ExponentialRetryAlgorithm {
-  /**
-   * Creates the polling algorithm, using the default {@code NanoClock} for time computations.
-   *
-   * @param globalSettings the settings
-   * @return timed poll algorithm
-   */
-  public static OperationTimedPollAlgorithm create(RetrySettings globalSettings) {
-    return new OperationTimedPollAlgorithm(globalSettings, NanoClock.getDefaultClock());
-  }
-
-  public static OperationTimedPollAlgorithm create(RetrySettings globalSettings, ApiClock clock) {
-    return new OperationTimedPollAlgorithm(globalSettings, clock);
-  }
-
-  private OperationTimedPollAlgorithm(RetrySettings globalSettings, ApiClock clock) {
-    super(globalSettings, clock);
-  }
-
-  /**
-   * Returns {@code true} if another poll operation should be made or throws {@link
-   * CancellationException} otherwise.
-   *
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @return {@code true} if more attempts should be made, never returns {@code false} (throws
-   *     {@code CancellationException} instead)
-   * @throws CancellationException if no more attempts should be made
-   */
-  @Override
-  public boolean shouldRetry(TimedAttemptSettings nextAttemptSettings)
-      throws CancellationException {
-    if (super.shouldRetry(nextAttemptSettings)) {
-      return true;
-    }
-    throw new CancellationException();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/nativeimage/GoogleJsonClientFeature.java b/gax/src/main/java/com/google/api/gax/nativeimage/GoogleJsonClientFeature.java
deleted file mode 100644
index baa4bac92..000000000
--- a/gax/src/main/java/com/google/api/gax/nativeimage/GoogleJsonClientFeature.java
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.nativeimage;
-
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerClassForReflection;
-
-import org.graalvm.nativeimage.hosted.Feature;
-
-/** Configures Native Image settings for the Google JSON Client. */
-final class GoogleJsonClientFeature implements Feature {
-
-  private static final String GOOGLE_API_CLIENT_CLASS =
-      "com.google.api.client.googleapis.services.json.AbstractGoogleJsonClient";
-
-  private static final String GOOGLE_API_CLIENT_REQUEST_CLASS =
-      "com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest";
-
-  private static final String GENERIC_JSON_CLASS = "com.google.api.client.json.GenericJson";
-
-  @Override
-  public void beforeAnalysis(BeforeAnalysisAccess access) {
-    loadApiClient(access);
-    loadHttpClient(access);
-    loadMiscClasses(access);
-  }
-
-  private void loadApiClient(BeforeAnalysisAccess access) {
-    // For com.google.api-client:google-api-client
-    Class<?> googleApiClientClass = access.findClassByName(GOOGLE_API_CLIENT_CLASS);
-
-    if (googleApiClientClass != null) {
-      // All reachable instances of the AbstractGoogleJsonClient must be registered.
-      access.registerSubtypeReachabilityHandler(
-          (duringAccess, subtype) -> registerClassForReflection(access, subtype.getName()),
-          googleApiClientClass);
-
-      // All reachable instances of the AbstractGoogleJsonClientRequest must be registered.
-      access.registerSubtypeReachabilityHandler(
-          (duringAccess, subtype) -> registerClassForReflection(access, subtype.getName()),
-          access.findClassByName(GOOGLE_API_CLIENT_REQUEST_CLASS));
-    }
-  }
-
-  private void loadHttpClient(BeforeAnalysisAccess access) {
-    // For com.google.http-client:google-http-client
-    Class<?> genericJsonClass = access.findClassByName(GENERIC_JSON_CLASS);
-
-    if (genericJsonClass != null) {
-      // All reachable instances of GenericJson must be registered.
-      access.registerSubtypeReachabilityHandler(
-          (duringAccess, subtype) -> registerClassForReflection(access, subtype.getName()),
-          genericJsonClass);
-
-      registerClassForReflection(access, "com.google.api.client.util.GenericData");
-      registerClassForReflection(access, "com.google.api.client.json.webtoken.JsonWebToken");
-      registerClassForReflection(access, "com.google.api.client.json.webtoken.JsonWebToken$Header");
-      registerClassForReflection(
-          access, "com.google.api.client.json.webtoken.JsonWebToken$Payload");
-      registerClassForReflection(
-          access, "com.google.api.client.json.webtoken.JsonWebSignature$Header");
-      registerClassForReflection(access, "com.google.api.client.json.webtoken.JsonWebSignature");
-      registerClassForReflection(access, "com.google.api.client.http.UrlEncodedContent");
-      registerClassForReflection(access, "com.google.api.client.http.GenericUrl");
-      registerClassForReflection(access, "com.google.api.client.http.HttpRequest");
-      registerClassForReflection(access, "com.google.api.client.http.HttpHeaders");
-    }
-  }
-
-  private void loadMiscClasses(BeforeAnalysisAccess access) {
-    registerClassForReflection(access, "com.google.common.util.concurrent.AbstractFuture");
-
-    registerClassForReflection(access, "com.google.common.util.concurrent.AbstractFuture$Waiter");
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/nativeimage/NativeImageUtils.java b/gax/src/main/java/com/google/api/gax/nativeimage/NativeImageUtils.java
deleted file mode 100644
index 603d26e3c..000000000
--- a/gax/src/main/java/com/google/api/gax/nativeimage/NativeImageUtils.java
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.nativeimage;
-
-import com.google.api.core.InternalApi;
-import java.lang.reflect.Method;
-import java.lang.reflect.Modifier;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import org.graalvm.nativeimage.hosted.Feature.FeatureAccess;
-import org.graalvm.nativeimage.hosted.RuntimeReflection;
-
-/** Internal class offering helper methods for registering methods/classes for reflection. */
-@InternalApi
-public class NativeImageUtils {
-
-  private static final Logger LOGGER = Logger.getLogger(NativeImageUtils.class.getName());
-  private static final String CLASS_REFLECTION_ERROR_MESSAGE =
-      "Failed to find {0} on the classpath for reflection.";
-
-  private NativeImageUtils() {}
-
-  /** Returns the method of a class or fails if it is not present. */
-  public static Method getMethodOrFail(Class<?> clazz, String methodName, Class<?>... params) {
-    try {
-      return clazz.getDeclaredMethod(methodName, params);
-    } catch (NoSuchMethodException e) {
-      throw new IllegalStateException(
-          String.format("Failed to find method %s for class %s", methodName, clazz.getName()), e);
-    }
-  }
-
-  /** Registers a class for reflective construction via its default constructor. */
-  public static void registerForReflectiveInstantiation(FeatureAccess access, String className) {
-    Class<?> clazz = access.findClassByName(className);
-    if (clazz != null) {
-      RuntimeReflection.register(clazz);
-      RuntimeReflection.registerForReflectiveInstantiation(clazz);
-    } else {
-      LOGGER.log(
-          Level.WARNING,
-          "Failed to find {0} on the classpath for reflective instantiation.",
-          className);
-    }
-  }
-
-  /** Registers all constructors of a class for reflection. */
-  public static void registerConstructorsForReflection(FeatureAccess access, String name) {
-    Class<?> clazz = access.findClassByName(name);
-    if (clazz != null) {
-      RuntimeReflection.register(clazz);
-      RuntimeReflection.register(clazz.getDeclaredConstructors());
-    } else {
-      LOGGER.log(Level.WARNING, CLASS_REFLECTION_ERROR_MESSAGE, name);
-    }
-  }
-
-  /** Registers an entire class for reflection use. */
-  public static void registerClassForReflection(FeatureAccess access, String name) {
-    Class<?> clazz = access.findClassByName(name);
-    if (clazz != null) {
-      RuntimeReflection.register(clazz);
-      RuntimeReflection.register(clazz.getDeclaredConstructors());
-      RuntimeReflection.register(clazz.getDeclaredFields());
-      RuntimeReflection.register(clazz.getDeclaredMethods());
-    } else {
-      LOGGER.log(Level.WARNING, CLASS_REFLECTION_ERROR_MESSAGE, name);
-    }
-  }
-
-  /**
-   * Registers the transitive class hierarchy of the provided {@code className} for reflection.
-   *
-   * <p>The transitive class hierarchy contains the class itself and its transitive set of
-   * *non-private* nested subclasses.
-   */
-  public static void registerClassHierarchyForReflection(FeatureAccess access, String className) {
-    Class<?> clazz = access.findClassByName(className);
-    if (clazz != null) {
-      registerClassForReflection(access, className);
-      for (Class<?> nestedClass : clazz.getDeclaredClasses()) {
-        if (!Modifier.isPrivate(nestedClass.getModifiers())) {
-          registerClassHierarchyForReflection(access, nestedClass.getName());
-        }
-      }
-    } else {
-      LOGGER.log(Level.WARNING, CLASS_REFLECTION_ERROR_MESSAGE, className);
-    }
-  }
-
-  /** Registers a class for unsafe reflective field access. */
-  public static void registerForUnsafeFieldAccess(
-      FeatureAccess access, String className, String... fields) {
-    Class<?> clazz = access.findClassByName(className);
-    if (clazz != null) {
-      RuntimeReflection.register(clazz);
-      for (String fieldName : fields) {
-        try {
-          RuntimeReflection.register(clazz.getDeclaredField(fieldName));
-        } catch (NoSuchFieldException ex) {
-          LOGGER.warning("Failed to register field " + fieldName + " for class " + className);
-          LOGGER.warning(ex.getMessage());
-        }
-      }
-    } else {
-      LOGGER.log(
-          Level.WARNING,
-          "Failed to find {0} on the classpath for unsafe fields access registration.",
-          className);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/nativeimage/OpenCensusFeature.java b/gax/src/main/java/com/google/api/gax/nativeimage/OpenCensusFeature.java
deleted file mode 100644
index a32cac4b3..000000000
--- a/gax/src/main/java/com/google/api/gax/nativeimage/OpenCensusFeature.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.nativeimage;
-
-import static com.google.api.gax.nativeimage.NativeImageUtils.registerForReflectiveInstantiation;
-
-import org.graalvm.nativeimage.hosted.Feature;
-
-/** Registers reflection usage in OpenCensus libraries. */
-final class OpenCensusFeature implements Feature {
-
-  private static final String TAGS_COMPONENT_CLASS = "io.opencensus.impl.tags.TagsComponentImpl";
-  private static final String STATS_COMPONENT_CLASS = "io.opencensus.impl.stats.StatsComponentImpl";
-
-  @Override
-  public void beforeAnalysis(BeforeAnalysisAccess access) {
-    if (access.findClassByName(STATS_COMPONENT_CLASS) != null) {
-      registerForReflectiveInstantiation(access, STATS_COMPONENT_CLASS);
-    }
-    if (access.findClassByName(TAGS_COMPONENT_CLASS) != null) {
-      registerForReflectiveInstantiation(access, "io.opencensus.impl.metrics.MetricsComponentImpl");
-      registerForReflectiveInstantiation(access, TAGS_COMPONENT_CLASS);
-      registerForReflectiveInstantiation(access, "io.opencensus.impl.trace.TraceComponentImpl");
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/AbstractFixedSizeCollection.java b/gax/src/main/java/com/google/api/gax/paging/AbstractFixedSizeCollection.java
deleted file mode 100644
index f843bc2dc..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/AbstractFixedSizeCollection.java
+++ /dev/null
@@ -1,181 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import com.google.api.client.util.Lists;
-import com.google.api.pathtemplate.ValidationException;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.AbstractIterator;
-import java.util.Iterator;
-import java.util.List;
-
-/** Partial implementation of {@link FixedSizeCollection}. */
-public abstract class AbstractFixedSizeCollection<
-        RequestT,
-        ResponseT,
-        ResourceT,
-        PageT extends AbstractPage<RequestT, ResponseT, ResourceT, PageT>,
-        CollectionT extends
-            AbstractFixedSizeCollection<RequestT, ResponseT, ResourceT, PageT, CollectionT>>
-    implements FixedSizeCollection<ResourceT> {
-
-  private final List<PageT> pageList;
-  private final int collectionSize;
-
-  protected AbstractFixedSizeCollection(List<PageT> pages, int collectionSize) {
-    this.pageList = pages;
-    this.collectionSize = collectionSize;
-  }
-
-  protected abstract CollectionT createCollection(List<PageT> pages, int collectionSize);
-
-  @Override
-  public Iterable<ResourceT> getValues() {
-    return new Iterable<ResourceT>() {
-      @Override
-      public Iterator<ResourceT> iterator() {
-        return new CollectionResourcesIterator();
-      }
-    };
-  }
-
-  @Override
-  public CollectionT getNextCollection() {
-    if (hasNextCollection()) {
-      PageT nextFirstPage = getLastPage().getNextPage();
-      List<PageT> pages = getPages(nextFirstPage, collectionSize);
-      return createCollection(pages, collectionSize);
-    } else {
-      return null;
-    }
-  }
-
-  @Override
-  public boolean hasNextCollection() {
-    return getLastPage().hasNextPage();
-  }
-
-  @Override
-  public String getNextPageToken() {
-    return getLastPage().getNextPageToken();
-  }
-
-  @Override
-  public int getCollectionSize() {
-    int size = 0;
-    for (PageT page : pageList) {
-      size += page.getPageElementCount();
-    }
-    return size;
-  }
-
-  private PageT getLastPage() {
-    return pageList.get(pageList.size() - 1);
-  }
-
-  /**
-   * Retrieve a list of pages with a total of collectionSize elements.
-   *
-   * <p>If the collectionSize parameter is greater than the number of elements in the firstPage
-   * object, additional pages will be retrieved from the underlying API. It is an error to choose a
-   * value of collectionSize that is less that the number of elements that already exist in the Page
-   * object.
-   */
-  List<PageT> getPages(final PageT firstPage, final int collectionSize) {
-    Preconditions.checkNotNull(firstPage);
-    Preconditions.checkState(collectionSize > 0);
-    Integer requestPageSize =
-        firstPage.getContext().getPageDescriptor().extractPageSize(firstPage.getRequest());
-    if (requestPageSize == null) {
-      throw new ValidationException(
-          "Error while expanding Page to FixedSizeCollection: No pageSize "
-              + "parameter found. The pageSize parameter must be set on the request "
-              + "object, and must be less than the collectionSize "
-              + "parameter, in order to create a FixedSizeCollection object.");
-    }
-    if (requestPageSize > collectionSize) {
-      throw new ValidationException(
-          "Error while expanding Page to FixedSizeCollection: collectionSize "
-              + "parameter is less than the pageSize optional argument specified on "
-              + "the request object. collectionSize: "
-              + collectionSize
-              + ", pageSize: "
-              + requestPageSize);
-    }
-    if (firstPage.getPageElementCount() > collectionSize) {
-      throw new ValidationException(
-          "Cannot construct a FixedSizeCollection with collectionSize less than the number of "
-              + "elements in the first page");
-    }
-
-    int remainingCount = collectionSize - firstPage.getPageElementCount();
-    List<PageT> pages = Lists.newArrayList();
-    pages.add(firstPage);
-    PageT currentPage = firstPage;
-    while (remainingCount > 0) {
-      currentPage = currentPage.getNextPage(remainingCount);
-      if (currentPage == null) {
-        break;
-      } else {
-        int rxElementCount = currentPage.getPageElementCount();
-        if (rxElementCount > remainingCount) {
-          throw new ValidationException(
-              "API returned a number of elements exceeding the specified page_size limit. "
-                  + "page_size: "
-                  + collectionSize
-                  + ", elements received: "
-                  + rxElementCount);
-        }
-        remainingCount -= rxElementCount;
-        pages.add(currentPage);
-      }
-    }
-    return pages;
-  }
-
-  private class CollectionResourcesIterator extends AbstractIterator<ResourceT> {
-
-    private final Iterator<PageT> pageIterator = pageList.iterator();
-    private Iterator<ResourceT> resourceIterator = pageIterator.next().getValues().iterator();
-
-    @Override
-    protected ResourceT computeNext() {
-      while (true) {
-        if (resourceIterator.hasNext()) {
-          return resourceIterator.next();
-        } else if (pageIterator.hasNext()) {
-          resourceIterator = pageIterator.next().getValues().iterator();
-        } else {
-          return endOfData();
-        }
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/AbstractPage.java b/gax/src/main/java/com/google/api/gax/paging/AbstractPage.java
deleted file mode 100644
index 805ec226e..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/AbstractPage.java
+++ /dev/null
@@ -1,185 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiExceptions;
-import com.google.api.gax.rpc.PageContext;
-import com.google.common.base.Strings;
-import com.google.common.collect.AbstractIterator;
-import com.google.common.collect.Iterables;
-import java.util.Iterator;
-
-/** Partial implementation of {@link AsyncPage}. */
-public abstract class AbstractPage<
-        RequestT,
-        ResponseT,
-        ResourceT,
-        PageT extends AbstractPage<RequestT, ResponseT, ResourceT, PageT>>
-    implements AsyncPage<ResourceT> {
-
-  private final PageContext<RequestT, ResponseT, ResourceT> context;
-  private final ResponseT response;
-
-  protected AbstractPage(PageContext<RequestT, ResponseT, ResourceT> context, ResponseT response) {
-    this.context = context;
-    this.response = response;
-  }
-
-  protected abstract PageT createPage(
-      PageContext<RequestT, ResponseT, ResourceT> context, ResponseT response);
-
-  @InternalApi("Visible for testing")
-  public ApiFuture<PageT> createPageAsync(
-      final PageContext<RequestT, ResponseT, ResourceT> context,
-      ApiFuture<ResponseT> futureResponse) {
-    return ApiFutures.transform(
-        futureResponse,
-        new ApiFunction<ResponseT, PageT>() {
-          @Override
-          public PageT apply(ResponseT input) {
-            return createPage(context, input);
-          }
-        },
-        directExecutor());
-  }
-
-  @Override
-  public boolean hasNextPage() {
-    return !getNextPageToken().equals(context.getPageDescriptor().emptyToken());
-  }
-
-  @Override
-  public String getNextPageToken() {
-    return Strings.nullToEmpty(context.getPageDescriptor().extractNextToken(response));
-  }
-
-  @Override
-  public PageT getNextPage() {
-    return getNextPageImpl(null);
-  }
-
-  public PageT getNextPage(int pageSize) {
-    return getNextPageImpl(pageSize);
-  }
-
-  @Override
-  public ApiFuture<PageT> getNextPageAsync() {
-    if (hasNextPage()) {
-      RequestT request =
-          context.getPageDescriptor().injectToken(context.getRequest(), getNextPageToken());
-      final PageContext<RequestT, ResponseT, ResourceT> nextContext = context.withRequest(request);
-      return createPageAsync(nextContext, callApi(nextContext));
-    } else {
-      return ApiFutures.immediateFuture(null);
-    }
-  }
-
-  private PageT getNextPageImpl(Integer pageSize) {
-    if (hasNextPage()) {
-      RequestT request =
-          context.getPageDescriptor().injectToken(context.getRequest(), getNextPageToken());
-      if (pageSize != null) {
-        request = context.getPageDescriptor().injectPageSize(request, pageSize);
-      }
-      PageContext<RequestT, ResponseT, ResourceT> nextContext = context.withRequest(request);
-      ResponseT response = ApiExceptions.callAndTranslateApiException(callApi(nextContext));
-      return createPage(nextContext, response);
-    } else {
-      return null;
-    }
-  }
-
-  private ApiFuture<ResponseT> callApi(PageContext<RequestT, ResponseT, ResourceT> nextContext) {
-    return nextContext
-        .getCallable()
-        .futureCall(nextContext.getRequest(), nextContext.getCallContext());
-  }
-
-  @Override
-  public Iterable<ResourceT> iterateAll() {
-    return new Iterable<ResourceT>() {
-      @Override
-      public Iterator<ResourceT> iterator() {
-        return new AllResourcesIterator();
-      }
-    };
-  }
-
-  @Override
-  public Iterable<ResourceT> getValues() {
-    return context.getPageDescriptor().extractResources(response);
-  }
-
-  public ResponseT getResponse() {
-    return response;
-  }
-
-  public RequestT getRequest() {
-    return context.getRequest();
-  }
-
-  public int getPageElementCount() {
-    return Iterables.size(context.getPageDescriptor().extractResources(response));
-  }
-
-  PageContext<RequestT, ResponseT, ResourceT> getContext() {
-    return context;
-  }
-
-  private class AllResourcesIterator extends AbstractIterator<ResourceT> {
-    private AbstractPage<RequestT, ResponseT, ResourceT, PageT> currentPage;
-    private Iterator<ResourceT> currentIterator;
-
-    private AllResourcesIterator() {
-      this.currentPage = AbstractPage.this;
-      this.currentIterator = this.currentPage.getValues().iterator();
-    }
-
-    @Override
-    protected ResourceT computeNext() {
-      while (true) {
-        if (currentIterator.hasNext()) {
-          return currentIterator.next();
-        }
-        currentPage = currentPage.getNextPage();
-        if (currentPage == null) {
-          return endOfData();
-        }
-        currentIterator = currentPage.getValues().iterator();
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/AbstractPagedListResponse.java b/gax/src/main/java/com/google/api/gax/paging/AbstractPagedListResponse.java
deleted file mode 100644
index 1d0597d4a..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/AbstractPagedListResponse.java
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import com.google.common.base.Preconditions;
-import com.google.common.collect.AbstractIterator;
-import java.util.Iterator;
-import java.util.List;
-
-/** Partial implementation of {@link com.google.api.gax.paging.PagedListResponse}. */
-public abstract class AbstractPagedListResponse<
-        RequestT,
-        ResponseT,
-        ResourceT,
-        PageT extends AbstractPage<RequestT, ResponseT, ResourceT, PageT>,
-        CollectionT extends
-            AbstractFixedSizeCollection<RequestT, ResponseT, ResourceT, PageT, CollectionT>>
-    implements PagedListResponse<ResourceT> {
-
-  private final PageT page;
-  private final CollectionT emptyCollection;
-
-  protected AbstractPagedListResponse(PageT page, CollectionT emptyCollection) {
-    this.page = page;
-    this.emptyCollection = emptyCollection;
-  }
-
-  @Override
-  public Iterable<ResourceT> iterateAll() {
-    return getPage().iterateAll();
-  }
-
-  @Override
-  public PageT getPage() {
-    return page;
-  }
-
-  @Override
-  public Iterable<PageT> iteratePages() {
-    return new Iterable<PageT>() {
-      @Override
-      public Iterator<PageT> iterator() {
-        return new AllPagesIterator(page);
-      }
-    };
-  }
-
-  @Override
-  public String getNextPageToken() {
-    return getPage().getNextPageToken();
-  }
-
-  @Override
-  public CollectionT expandToFixedSizeCollection(int collectionSize) {
-    List<PageT> pages = emptyCollection.getPages(page, collectionSize);
-    return emptyCollection.createCollection(pages, collectionSize);
-  }
-
-  @Override
-  public Iterable<CollectionT> iterateFixedSizeCollections(int collectionSize) {
-    final CollectionT firstCollection = expandToFixedSizeCollection(collectionSize);
-    return new Iterable<CollectionT>() {
-      @Override
-      public Iterator<CollectionT> iterator() {
-        return new AllCollectionsIterator(firstCollection);
-      }
-    };
-  }
-
-  private interface Next<T> {
-    T next(T current);
-  }
-
-  private class AllPagesIterator extends NextIterator<PageT> {
-    private AllPagesIterator(PageT firstCollection) {
-      super(
-          firstCollection,
-          new Next<PageT>() {
-            @Override
-            public PageT next(PageT current) {
-              return current.getNextPage();
-            }
-          });
-    }
-  }
-
-  private class AllCollectionsIterator extends NextIterator<CollectionT> {
-    private AllCollectionsIterator(CollectionT firstCollection) {
-      super(
-          firstCollection,
-          new Next<CollectionT>() {
-            @Override
-            public CollectionT next(CollectionT current) {
-              return current.getNextCollection();
-            }
-          });
-    }
-  }
-
-  private class NextIterator<T> extends AbstractIterator<T> {
-
-    private T current;
-    private final Next<T> fetcher;
-    private boolean computeFirst = true;
-
-    private NextIterator(T first, Next<T> fetcher) {
-      this.current = Preconditions.checkNotNull(first);
-      this.fetcher = fetcher;
-    }
-
-    @Override
-    protected T computeNext() {
-      if (computeFirst) {
-        computeFirst = false;
-        return current;
-      } else {
-        current = fetcher.next(current);
-        if (current == null) {
-          return endOfData();
-        } else {
-          return current;
-        }
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/AsyncPage.java b/gax/src/main/java/com/google/api/gax/paging/AsyncPage.java
deleted file mode 100644
index 9f139911c..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/AsyncPage.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import com.google.api.core.ApiFuture;
-
-/** An AsyncPage extends a {@link Page} object with a getNextPageAsync method. */
-public interface AsyncPage<ResourceT> extends Page<ResourceT> {
-
-  /**
-   * Returns a future for the Page object, retrieved using the next page token. If there are no more
-   * pages, returns a future which will immediately provide null. The hasNextPage() method can be
-   * used to check if a Page object is available.
-   */
-  ApiFuture<? extends AsyncPage<ResourceT>> getNextPageAsync();
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/FixedSizeCollection.java b/gax/src/main/java/com/google/api/gax/paging/FixedSizeCollection.java
deleted file mode 100644
index f3a7684e5..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/FixedSizeCollection.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-/**
- * A FixedSizeCollection object wraps multiple API list method responses into a single collection
- * with a fixed number of elements.
- *
- * <p>Callers can iterate over the FixedSizeCollection object to get all elements in the collection.
- * The number of elements is guaranteed to be equal to the value of the collectionSize parameter
- * passed to expandPage(), unless the API has no more elements to return. The FixedSizeCollection
- * object also provides methods to retrieve additional FixedSizeCollections using the page token.
- */
-public interface FixedSizeCollection<ResourceT> {
-
-  /**
-   * Returns the number of elements in the collection. This will be equal to the collectionSize
-   * parameter used at construction unless there are no elements remaining to be retrieved.
-   */
-  int getCollectionSize();
-
-  /** Returns true if there are more elements that can be retrieved from the API. */
-  boolean hasNextCollection();
-
-  /**
-   * Returns a page token that can be passed into the API list method to retrieve additional
-   * elements.
-   */
-  String getNextPageToken();
-
-  /** Retrieves the next FixedSizeCollection using one or more API calls. */
-  FixedSizeCollection<ResourceT> getNextCollection();
-
-  /** Returns an iterable over the elements in this FixedSizeCollection. */
-  Iterable<ResourceT> getValues();
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/Page.java b/gax/src/main/java/com/google/api/gax/paging/Page.java
deleted file mode 100644
index abacde970..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/Page.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-/**
- * A Page object wraps an API list method response.
- *
- * <p>Callers can iterate over the Page object to get all elements returned in the page. The Page
- * object also provides methods to retrieve additional pages using the page token, and to get the
- * API request and response objects.
- */
-public interface Page<ResourceT> {
-  /** Returns true if there are more pages that can be retrieved from the API. */
-  boolean hasNextPage();
-
-  /**
-   * Returns the next page token from the response, or an empty string if there are no more pages.
-   */
-  String getNextPageToken();
-
-  /**
-   * Retrieves the next Page object using the next page token, or {@code null} if there are no more
-   * pages. The hasNextPage() method can be used to check if a Page object is available.
-   */
-  Page<ResourceT> getNextPage();
-
-  /**
-   * Returns an iterable that traverses all of the elements of the underlying data source. The data
-   * is fetched lazily page by page, where each page may contain multiple elements. A new page is
-   * fetched whenever the elements of any particular page are exhausted.
-   */
-  Iterable<ResourceT> iterateAll();
-
-  /** Returns an iterable over the elements in this page. */
-  Iterable<ResourceT> getValues();
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/PagedListResponse.java b/gax/src/main/java/com/google/api/gax/paging/PagedListResponse.java
deleted file mode 100644
index 551808987..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/PagedListResponse.java
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-/**
- * Response for paged results from a list API method
- *
- * <p>This class is used to access the results of a paged list API method. The management of page
- * tokens can be handled automatically, or by the caller. Results can be accessed on a per-element
- * or per-page basis.
- */
-public interface PagedListResponse<ResourceT> {
-  /**
-   * Returns an iterable that traverses all of the elements of the underlying data source. The data
-   * is fetched lazily page by page, where each page may contain multiple elements. A new page is
-   * fetched whenever the elements of any particular page are exhausted. This method is not
-   * thread-safe.
-   */
-  Iterable<ResourceT> iterateAll();
-
-  /** Returns the current page of results. Note: This method is not thread-safe. */
-  Page<ResourceT> getPage();
-
-  /**
-   * Return an iterable over all Page objects. Page objects are retrieved lazily via API calls until
-   * all elements have been retrieved.
-   */
-  Iterable<? extends Page<ResourceT>> iteratePages();
-
-  /**
-   * Returns the token for the next page or an empty string if no more results. Note: This method is
-   * not thread-safe.
-   */
-  String getNextPageToken();
-
-  /**
-   * Returns a collection of elements with a fixed size set by the collectionSize parameter. The
-   * collection will only contain fewer than collectionSize elements if there are no more pages to
-   * be retrieved from the server.
-   *
-   * <p>NOTE: it is an error to call this method if the optional parameter 'page_size' has not been
-   * set in the original API call. It is also an error if the collectionSize parameter is less than
-   * the page_size.
-   */
-  FixedSizeCollection<ResourceT> expandToFixedSizeCollection(int collectionSize);
-
-  /**
-   * Returns an iterable over fixed size collections of results. The collections are retrieved
-   * lazily from the underlying API.
-   *
-   * <p>Each collection will have collectionSize elements, with the exception of the final
-   * collection which may contain fewer elements.
-   *
-   * <p>NOTE: it is an error to call this method if the optional parameter 'page_size' has not been
-   * set in the original API call. It is also an error if the collectionSize parameter is less than
-   * the page_size.
-   */
-  Iterable<? extends FixedSizeCollection<ResourceT>> iterateFixedSizeCollections(
-      int collectionSize);
-}
diff --git a/gax/src/main/java/com/google/api/gax/paging/Pages.java b/gax/src/main/java/com/google/api/gax/paging/Pages.java
deleted file mode 100644
index fcd8a5932..000000000
--- a/gax/src/main/java/com/google/api/gax/paging/Pages.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import java.util.Collections;
-
-/** Utility class for {@link Page}s. */
-public class Pages {
-  private Pages() {}
-
-  /** Returns a page that contains nothing. */
-  public static <ResourceT> Page<ResourceT> empty() {
-    return new Page<ResourceT>() {
-      @Override
-      public boolean hasNextPage() {
-        return false;
-      }
-
-      @Override
-      public String getNextPageToken() {
-        return "";
-      }
-
-      @Override
-      public Page<ResourceT> getNextPage() {
-        return null;
-      }
-
-      @Override
-      public Iterable<ResourceT> iterateAll() {
-        return Collections.emptyList();
-      }
-
-      @Override
-      public Iterable<ResourceT> getValues() {
-        return Collections.emptyList();
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/BasicResultRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/BasicResultRetryAlgorithm.java
deleted file mode 100644
index b33f131be..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/BasicResultRetryAlgorithm.java
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * A basic implementation of {@link ResultRetryAlgorithm}. Using this implementation would mean that
- * all exceptions should be retried, all responses should be accepted (including {@code null}) and
- * no retrying process should ever be canceled.
- *
- * @param <ResponseT> attempt response type
- */
-public class BasicResultRetryAlgorithm<ResponseT>
-    implements ResultRetryAlgorithmWithContext<ResponseT> {
-  /**
-   * Always returns null, indicating that this algorithm does not provide any specific settings for
-   * the next attempt.
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    return null;
-  }
-
-  /**
-   * Always returns null, indicating that this algorithm does not provide any specific settings for
-   * the next attempt.
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    return createNextAttempt(previousThrowable, previousResponse, previousSettings);
-  }
-
-  /**
-   * Returns {@code true} if an exception was thrown ({@code previousThrowable != null}), {@code
-   * false} otherwise.
-   */
-  @Override
-  public boolean shouldRetry(Throwable previousThrowable, ResponseT previousResponse) {
-    return previousThrowable != null;
-  }
-
-  /**
-   * Returns {@code true} if an exception was thrown ({@code previousThrowable != null}), {@code
-   * false} otherwise.
-   */
-  @Override
-  public boolean shouldRetry(
-      RetryingContext context, Throwable previousThrowable, ResponseT previousResponse)
-      throws CancellationException {
-    return shouldRetry(previousThrowable, previousResponse);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/BasicRetryingFuture.java b/gax/src/main/java/com/google/api/gax/retrying/BasicRetryingFuture.java
deleted file mode 100644
index de7b5b5ac..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/BasicRetryingFuture.java
+++ /dev/null
@@ -1,283 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.retrying;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.common.util.concurrent.AbstractFuture;
-import com.google.common.util.concurrent.MoreExecutors;
-import java.util.concurrent.Callable;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.RejectedExecutionException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-/**
- * For internal use only.
- *
- * <p>Basic implementation of {@link RetryingFuture} interface. On its own, suitable for usage in
- * 'busy loop' retry implementations. Can be used as the basis for more advanced implementations.
- *
- * <p>This class is thread-safe.
- */
-class BasicRetryingFuture<ResponseT> extends AbstractFuture<ResponseT>
-    implements RetryingFuture<ResponseT> {
-
-  final Object lock = new Object();
-
-  private final Callable<ResponseT> callable;
-
-  private final RetryAlgorithm<ResponseT> retryAlgorithm;
-  private final RetryingContext retryingContext;
-
-  private volatile TimedAttemptSettings attemptSettings;
-
-  private volatile ApiFuture<ResponseT> latestCompletedAttemptResult;
-  private volatile ApiFuture<ResponseT> attemptResult;
-
-  private static final Logger LOG = Logger.getLogger(BasicRetryingFuture.class.getName());
-
-  BasicRetryingFuture(
-      Callable<ResponseT> callable,
-      RetryAlgorithm<ResponseT> retryAlgorithm,
-      RetryingContext context) {
-    this.callable = checkNotNull(callable);
-    this.retryAlgorithm = checkNotNull(retryAlgorithm);
-    this.retryingContext = checkNotNull(context);
-
-    this.attemptSettings = retryAlgorithm.createFirstAttempt(context);
-
-    // A micro crime, letting "this" reference to escape from constructor before initialization is
-    // completed (via internal non-static class CompletionListener). But it is guaranteed to be ok,
-    // since listener is guaranteed to be called only after this future is
-    // completed and this future is guaranteed to be completed only after it is initialized. Also
-    // since "super" is called explicitly here there are no unexpected overrides of addListener
-    // here.
-    super.addListener(new CompletionListener(), MoreExecutors.directExecutor());
-  }
-
-  @Override
-  public void setAttemptFuture(ApiFuture<ResponseT> attemptFuture) {
-    try {
-      if (isDone()) {
-        return;
-      }
-      ResponseT response = attemptFuture.get();
-      handleAttempt(null, response);
-    } catch (ExecutionException e) {
-      handleAttempt(e.getCause(), null);
-    } catch (Throwable e) {
-      handleAttempt(e, null);
-    }
-  }
-
-  @Override
-  public Callable<ResponseT> getCallable() {
-    return callable;
-  }
-
-  @Override
-  public TimedAttemptSettings getAttemptSettings() {
-    synchronized (lock) {
-      return attemptSettings;
-    }
-  }
-
-  @Override
-  public ApiFuture<ResponseT> peekAttemptResult() {
-    synchronized (lock) {
-      return latestCompletedAttemptResult;
-    }
-  }
-
-  // Lazily initializes attempt result. This allows to prevent overhead of relatively
-  // heavy (and in most cases redundant) settable future instantiation on each attempt, plus reduces
-  // possibility of callback chaining going into an infinite loop in case of buggy external
-  // callbacks implementation.
-  @Override
-  public ApiFuture<ResponseT> getAttemptResult() {
-    synchronized (lock) {
-      if (attemptResult == null) {
-        attemptResult = new NonCancellableFuture<>();
-      }
-      return attemptResult;
-    }
-  }
-
-  // Called in the beginning of handleAttempt() and completion listeners to cleanup all attempt
-  // service data (callbacks and stuff)
-  void clearAttemptServiceData() {
-    // no-op for the basic implementation
-  }
-
-  // "super." is used here to avoid infinite loops of callback chains
-  void handleAttempt(Throwable throwable, ResponseT response) {
-    ApiTracer tracer = retryingContext.getTracer();
-
-    synchronized (lock) {
-      try {
-        clearAttemptServiceData();
-        if (throwable instanceof CancellationException) {
-          // An attempt triggered cancellation.
-          // In almost all cases, the operation caller caused the attempt to trigger the
-          // cancellation by invoking cancel() on the CallbackChainRetryingFuture, which cancelled
-          // the current attempt.
-          // In a theoretical scenario, the attempt callable might've thrown the exception on its
-          // own volition. However it's currently impossible to disambiguate the 2 scenarios.
-          tracer.attemptCancelled();
-          super.cancel(false);
-        } else if (throwable instanceof RejectedExecutionException) {
-          // external executor cannot continue retrying
-          tracer.attemptPermanentFailure(throwable);
-          super.setException(throwable);
-        }
-        if (isDone()) {
-          return;
-        }
-
-        TimedAttemptSettings nextAttemptSettings =
-            retryAlgorithm.createNextAttempt(retryingContext, throwable, response, attemptSettings);
-        boolean shouldRetry =
-            retryAlgorithm.shouldRetry(retryingContext, throwable, response, nextAttemptSettings);
-        if (shouldRetry) {
-          // Log retry info
-          if (LOG.isLoggable(Level.FINEST)) {
-            LOG.log(
-                Level.FINEST,
-                "Retrying with:\n{0}\n{1}\n{2}\n{3}",
-                new Object[] {
-                  "enclosingMethod: "
-                      + (callable.getClass().getEnclosingMethod() != null
-                          ? callable.getClass().getEnclosingMethod().getName()
-                          : ""),
-                  "attemptCount: " + attemptSettings.getAttemptCount(),
-                  "delay: " + attemptSettings.getRetryDelay(),
-                  "retriableException: " + throwable
-                });
-          }
-          tracer.attemptFailed(throwable, nextAttemptSettings.getRandomizedRetryDelay());
-          attemptSettings = nextAttemptSettings;
-          setAttemptResult(throwable, response, true);
-          // a new attempt will be (must be) scheduled by an external executor
-        } else if (throwable != null) {
-          if (retryAlgorithm.shouldRetryBasedOnResult(retryingContext, throwable, response)) {
-            tracer.attemptFailedRetriesExhausted(throwable);
-          } else {
-            tracer.attemptPermanentFailure(throwable);
-          }
-          super.setException(throwable);
-        } else {
-          tracer.attemptSucceeded();
-          super.set(response);
-        }
-      } catch (CancellationException e) {
-        // A retry algorithm triggered cancellation.
-        tracer.attemptFailedRetriesExhausted(e);
-        super.cancel(false);
-      } catch (Exception e) {
-        // Should never happen, but still possible in case of buggy retry algorithm implementation.
-        // Any bugs/exceptions (except CancellationException) in retry algorithms immediately
-        // terminate retrying future and set the result to the thrown exception.
-        tracer.attemptPermanentFailure(e);
-        super.setException(e);
-      }
-    }
-  }
-
-  // Sets attempt result futures. Note the "attempt result future" and "attempt future" are not same
-  // things because there are more attempt futures than attempt result futures.
-  // See AttemptCallable.call() for an example of such condition.
-  //
-  // The assignments order in this method is crucial. Wrong ordering may lead to infinite
-  // loops in callback chains.
-  //
-  // If this is not the last attempt this method sets attemptResult to null, so the next
-  // getAttemptResult() call will return a new future, tracking the new attempt. Otherwise
-  // attemptResult is set to the same result as the one returned by peekAttemptResult(), indicating
-  // that the ultimate unmodifiable result of the whole future was reached.
-  private void setAttemptResult(Throwable throwable, ResponseT response, boolean shouldRetry) {
-    ApiFuture<ResponseT> prevAttemptResult = attemptResult;
-    try {
-      if (throwable instanceof CancellationException) {
-        NonCancellableFuture<ResponseT> future = new NonCancellableFuture<>();
-        future.cancelPrivately();
-        latestCompletedAttemptResult = future;
-        attemptResult = shouldRetry ? null : latestCompletedAttemptResult;
-        if (prevAttemptResult instanceof NonCancellableFuture) {
-          ((NonCancellableFuture<ResponseT>) prevAttemptResult).cancelPrivately();
-        }
-      } else if (throwable != null) {
-        latestCompletedAttemptResult = ApiFutures.immediateFailedFuture(throwable);
-        attemptResult = shouldRetry ? null : latestCompletedAttemptResult;
-        if (prevAttemptResult instanceof NonCancellableFuture) {
-          ((NonCancellableFuture<ResponseT>) prevAttemptResult).setExceptionPrivately(throwable);
-        }
-      } else {
-        latestCompletedAttemptResult = ApiFutures.immediateFuture(response);
-        attemptResult = shouldRetry ? null : latestCompletedAttemptResult;
-        if (prevAttemptResult instanceof NonCancellableFuture) {
-          ((NonCancellableFuture<ResponseT>) prevAttemptResult).setPrivately(response);
-        }
-      }
-    } catch (Exception e) {
-      // Usually should not happen but is still possible, for example if one of the attempt result
-      // callbacks throws an exception. An example of such condition is the OperationFuture
-      // which uses ApiFutures.transform(), which actually assign callbacks to the attempt result
-      // futures, and those can fail, for example if metadata class is a wrong one.
-      //
-      // The exception is swallowed to avoid buggy callback implementations breaking retrying future
-      // execution. In case if a callback is executed in a separate thread executor (the recommended
-      // way) the exception will be thrown in a separate thread and will not be swallowed by this
-      // catch block anyways.
-    }
-  }
-
-  private class CompletionListener implements Runnable {
-    @Override
-    public void run() {
-      synchronized (lock) {
-        try {
-          clearAttemptServiceData();
-          ResponseT response = get();
-          setAttemptResult(null, response, false);
-        } catch (ExecutionException e) {
-          setAttemptResult(e.getCause(), null, false);
-        } catch (Throwable e) {
-          setAttemptResult(e, null, false);
-        }
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/CallbackChainRetryingFuture.java b/gax/src/main/java/com/google/api/gax/retrying/CallbackChainRetryingFuture.java
deleted file mode 100644
index f6714e23b..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/CallbackChainRetryingFuture.java
+++ /dev/null
@@ -1,143 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFuture;
-import com.google.common.util.concurrent.MoreExecutors;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
-
-/**
- * For internal use only.
- *
- * <p>Callback chaining implementation of {@link RetryingFuture} interface. Suitable for retry
- * implementations, when each attempt is scheduled in a specific thread pool (i.e. each attempt may
- * be executed by a different thread).
- *
- * <p>After each attempt, if it is determined as retriable by the retrying algorithm, this
- * implementation schedules a new attempt using the provided retrying executor and assigns a
- * callback to the new scheduled attempt (to examine it result in the future and either accept,
- * reject or repeat the process again).
- *
- * <p>This class is thread-safe.
- */
-class CallbackChainRetryingFuture<ResponseT> extends BasicRetryingFuture<ResponseT> {
-  private final ScheduledRetryingExecutor<ResponseT> retryingExecutor;
-  private volatile AttemptCompletionListener attemptFutureCompletionListener;
-
-  CallbackChainRetryingFuture(
-      Callable<ResponseT> callable,
-      RetryAlgorithm<ResponseT> retryAlgorithm,
-      ScheduledRetryingExecutor<ResponseT> retryingExecutor,
-      RetryingContext context) {
-    super(callable, retryAlgorithm, context);
-    this.retryingExecutor = checkNotNull(retryingExecutor);
-  }
-
-  @Override
-  public boolean cancel(boolean mayInterruptIfRunning) {
-    synchronized (lock) {
-      if (attemptFutureCompletionListener == null) {
-        // explicit retry future cancellation, most probably even before the first attempt started
-        return super.cancel(mayInterruptIfRunning);
-      }
-      // will result in attempt triggered cancellation of the whole future via callback chain
-      attemptFutureCompletionListener.attemptFuture.cancel(mayInterruptIfRunning);
-      return isCancelled();
-    }
-  }
-
-  @Override
-  public void setAttemptFuture(ApiFuture<ResponseT> attemptFuture) {
-    if (isDone()) {
-      return;
-    }
-    synchronized (lock) {
-      if (isDone()) {
-        return;
-      }
-      attemptFutureCompletionListener = new AttemptCompletionListener(attemptFuture);
-      // Using direct addListener instead of ApiFutures.addCallback allows greatly reduce
-      // layering. Also listener is more suitable here (as we don't really need two methods -
-      // one for failure and one for success).
-      attemptFuture.addListener(attemptFutureCompletionListener, MoreExecutors.directExecutor());
-    }
-  }
-
-  @Override
-  void clearAttemptServiceData() {
-    synchronized (lock) {
-      attemptFutureCompletionListener = null;
-    }
-  }
-
-  private class AttemptCompletionListener implements Runnable {
-    private final Future<ResponseT> attemptFuture;
-
-    AttemptCompletionListener(Future<ResponseT> attemptFuture) {
-      this.attemptFuture = attemptFuture;
-    }
-
-    @Override
-    public void run() {
-      try {
-        ResponseT response = attemptFuture.get();
-        handle(null, response);
-      } catch (ExecutionException e) {
-        handle(e.getCause(), null);
-      } catch (Throwable e) {
-        handle(e, null);
-      }
-    }
-
-    private void handle(Throwable t, ResponseT response) {
-      // Essential check, to ensure that we do not execute callback of an abandoned attempt.
-      // First before the lock, to increase performance and reduce chance of deadlocking
-      // (should never happen, but being extra cautious is appropriate here).
-      if (this != attemptFutureCompletionListener || isDone()) {
-        return;
-      }
-      synchronized (lock) {
-        // same check as before, now under lock
-        if (this != attemptFutureCompletionListener || isDone()) {
-          return;
-        }
-        handleAttempt(t, response);
-        if (!isDone()) {
-          ApiFuture<ResponseT> attempt = retryingExecutor.submit(CallbackChainRetryingFuture.this);
-          setAttemptFuture(attempt);
-        }
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/DirectRetryingExecutor.java b/gax/src/main/java/com/google/api/gax/retrying/DirectRetryingExecutor.java
deleted file mode 100644
index 54b7750ca..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/DirectRetryingExecutor.java
+++ /dev/null
@@ -1,126 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import java.io.InterruptedIOException;
-import java.nio.channels.ClosedByInterruptException;
-import java.util.concurrent.Callable;
-import org.threeten.bp.Duration;
-
-/**
- * The retry executor which executes attempts in the current thread, potentially causing the current
- * thread to sleep for the specified amount of time before execution.
- *
- * <p>This class is thread-safe.
- *
- * @param <ResponseT> response type
- */
-public class DirectRetryingExecutor<ResponseT> implements RetryingExecutorWithContext<ResponseT> {
-
-  private final RetryAlgorithm<ResponseT> retryAlgorithm;
-
-  /**
-   * Creates a new direct retrying executor instance, which will be using {@code retryAlgorithm} to
-   * determine retrying strategy.
-   *
-   * @param retryAlgorithm retry algorithm to use for attempts execution
-   * @throws NullPointerException if {@code retryAlgorithm} is null
-   */
-  public DirectRetryingExecutor(RetryAlgorithm<ResponseT> retryAlgorithm) {
-    this.retryAlgorithm = checkNotNull(retryAlgorithm);
-  }
-
-  /**
-   * Creates a {@link RetryingFuture}, which is a facade, returned to the client code to wait for
-   * any retriable operation to complete. The future is bounded to {@code this} executor instance.
-   *
-   * @param callable the actual callable, which should be executed in a retriable context
-   * @return retrying future facade
-   */
-  @Override
-  public RetryingFuture<ResponseT> createFuture(Callable<ResponseT> callable) {
-    return createFuture(callable, NoopRetryingContext.create());
-  }
-
-  /**
-   * Creates a {@link RetryingFuture}, which is a facade, returned to the client code to wait for
-   * any retriable operation to complete. The future is bounded to {@code this} executor instance.
-   *
-   * @param callable the actual callable, which should be executed in a retriable context
-   * @return retrying future facade
-   */
-  @Override
-  public RetryingFuture<ResponseT> createFuture(
-      Callable<ResponseT> callable, RetryingContext context) {
-    return new BasicRetryingFuture<>(callable, retryAlgorithm, context);
-  }
-
-  /**
-   * Submits an attempt for execution in the current thread, causing the current thread to sleep for
-   * the specified by the {@link RetryingFuture#getAttemptSettings()} amount of time. As result,
-   * this method completes execution only after the specified {@code retryingFuture} completes.
-   *
-   * @param retryingFuture the future previously returned by {@link #createFuture(Callable,
-   *     RetryingContext)}
-   * @return returns completed {@code retryingFuture}
-   */
-  @Override
-  public ApiFuture<ResponseT> submit(RetryingFuture<ResponseT> retryingFuture) {
-    while (!retryingFuture.isDone()) {
-      try {
-        sleep(retryingFuture.getAttemptSettings().getRandomizedRetryDelay());
-        ResponseT response = retryingFuture.getCallable().call();
-        retryingFuture.setAttemptFuture(ApiFutures.immediateFuture(response));
-      } catch (InterruptedException | InterruptedIOException | ClosedByInterruptException e) {
-        Thread.currentThread().interrupt();
-        retryingFuture.setAttemptFuture(ApiFutures.<ResponseT>immediateFailedFuture(e));
-      } catch (Exception e) {
-        retryingFuture.setAttemptFuture(ApiFutures.<ResponseT>immediateFailedFuture(e));
-      }
-    }
-    return retryingFuture;
-  }
-
-  /**
-   * This method simply calls {@link Thread#sleep(long)}.
-   *
-   * @param delay time to sleep
-   * @throws InterruptedException if any thread has interrupted the current thread
-   */
-  protected void sleep(Duration delay) throws InterruptedException {
-    if (Duration.ZERO.compareTo(delay) < 0) {
-      Thread.sleep(delay.toMillis());
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ExponentialPollAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/ExponentialPollAlgorithm.java
deleted file mode 100644
index 5a68da1a5..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ExponentialPollAlgorithm.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.ApiClock;
-
-/**
- * The timed poll algorithm which uses jittered exponential backoff factor for calculating the next
- * poll execution time and throws {@link PollException} in case if total timeout or total number of
- * attempts is reached.
- *
- * <p>This class is thread-safe.
- */
-public class ExponentialPollAlgorithm extends ExponentialRetryAlgorithm {
-  /**
-   * Creates a new exponential poll algorithm instance.
-   *
-   * @param globalSettings global poll settings (attempt independent)
-   * @param clock clock to use for time-specific calculations
-   * @throws NullPointerException if either {@code globalSettings} or {@code clock} is null
-   */
-  public ExponentialPollAlgorithm(RetrySettings globalSettings, ApiClock clock) {
-    super(globalSettings, clock);
-  }
-
-  /**
-   * Returns {@code true} if another poll operation should be made or throws {@link PollException},
-   * if either total timeout or total number of attempts is exceeded.
-   *
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @return {@code true} if more attempts should be made, never returns {@code false} (throws
-   *     {@code PollException} instead)
-   * @throws PollException if no more attempts should be made
-   */
-  @Override
-  public boolean shouldRetry(TimedAttemptSettings nextAttemptSettings) throws PollException {
-    if (super.shouldRetry(nextAttemptSettings)) {
-      return true;
-    }
-    throw new PollException(
-        "total timeout or maximum number of attempts exceeded; current settings: "
-            + nextAttemptSettings.getGlobalSettings());
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ExponentialRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/ExponentialRetryAlgorithm.java
deleted file mode 100644
index 26beb8f0b..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ExponentialRetryAlgorithm.java
+++ /dev/null
@@ -1,258 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiClock;
-import java.util.concurrent.ThreadLocalRandom;
-import org.threeten.bp.Duration;
-
-/**
- * The timed retry algorithm which uses jittered exponential backoff factor for calculating the next
- * attempt execution time.
- *
- * <p>This class is thread-safe.
- */
-public class ExponentialRetryAlgorithm implements TimedRetryAlgorithmWithContext {
-
-  private final RetrySettings globalSettings;
-  private final ApiClock clock;
-
-  /**
-   * Creates a new exponential retry algorithm instance.
-   *
-   * @param globalSettings global retry settings (attempt independent)
-   * @param clock clock to use for time-specific calculations
-   * @throws NullPointerException if either {@code globalSettings} or {@code clock} is null
-   */
-  public ExponentialRetryAlgorithm(RetrySettings globalSettings, ApiClock clock) {
-    this.globalSettings = checkNotNull(globalSettings);
-    this.clock = checkNotNull(clock);
-  }
-
-  /**
-   * Creates a first attempt {@link TimedAttemptSettings}. The first attempt is configured to be
-   * executed immediately.
-   *
-   * @return first attempt settings
-   */
-  @Override
-  public TimedAttemptSettings createFirstAttempt() {
-    return TimedAttemptSettings.newBuilder()
-        .setGlobalSettings(globalSettings)
-        .setRetryDelay(Duration.ZERO)
-        .setRpcTimeout(globalSettings.getInitialRpcTimeout())
-        .setRandomizedRetryDelay(Duration.ZERO)
-        .setAttemptCount(0)
-        .setOverallAttemptCount(0)
-        .setFirstAttemptStartTimeNanos(clock.nanoTime())
-        .build();
-  }
-
-  /**
-   * Creates a first attempt {@link TimedAttemptSettings}. The first attempt is configured to be
-   * executed immediately.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes
-   * @return first attempt settings
-   */
-  @Override
-  public TimedAttemptSettings createFirstAttempt(RetryingContext context) {
-    if (context.getRetrySettings() == null) {
-      return createFirstAttempt();
-    }
-
-    RetrySettings retrySettings = context.getRetrySettings();
-    return TimedAttemptSettings.newBuilder()
-        // Use the given retrySettings rather than the settings this was created with.
-        // Attempts created using the TimedAttemptSettings built here will use these
-        // retrySettings, but a new call will not (unless overridden again).
-        .setGlobalSettings(retrySettings)
-        .setRpcTimeout(retrySettings.getInitialRpcTimeout())
-        .setRetryDelay(Duration.ZERO)
-        .setRandomizedRetryDelay(Duration.ZERO)
-        .setAttemptCount(0)
-        .setOverallAttemptCount(0)
-        .setFirstAttemptStartTimeNanos(clock.nanoTime())
-        .build();
-  }
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}. The implementation increments the current
-   * attempt count and uses randomized exponential backoff factor for calculating next attempt
-   * execution time.
-   *
-   * @param previousSettings previous attempt settings
-   * @return next attempt settings
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(TimedAttemptSettings previousSettings) {
-    RetrySettings settings = previousSettings.getGlobalSettings();
-
-    // The retry delay is determined as follows:
-    //     attempt #0  - not used (initial attempt is always made immediately);
-    //     attempt #1  - use initialRetryDelay;
-    //     attempt #2+ - use the calculated value (i.e. the following if statement is true only
-    //                   if we are about to calculate the value for the upcoming 2nd+ attempt).
-    long newRetryDelay = settings.getInitialRetryDelay().toMillis();
-    if (previousSettings.getAttemptCount() > 0) {
-      newRetryDelay =
-          (long) (settings.getRetryDelayMultiplier() * previousSettings.getRetryDelay().toMillis());
-      newRetryDelay = Math.min(newRetryDelay, settings.getMaxRetryDelay().toMillis());
-    }
-    Duration randomDelay = Duration.ofMillis(nextRandomLong(newRetryDelay));
-
-    // The rpc timeout is determined as follows:
-    //     attempt #0  - use the initialRpcTimeout;
-    //     attempt #1+ - use the calculated value, or the time remaining in totalTimeout if the
-    //                   calculated value would exceed the totalTimeout.
-    long newRpcTimeout =
-        (long) (settings.getRpcTimeoutMultiplier() * previousSettings.getRpcTimeout().toMillis());
-    newRpcTimeout = Math.min(newRpcTimeout, settings.getMaxRpcTimeout().toMillis());
-
-    // The totalTimeout could be zero if a callable is only using maxAttempts to limit retries.
-    // If set, calculate time remaining in the totalTimeout since the start, taking into account the
-    // next attempt's delay, in order to truncate the RPC timeout should it exceed the totalTimeout.
-    if (!settings.getTotalTimeout().isZero()) {
-      Duration timeElapsed =
-          Duration.ofNanos(clock.nanoTime())
-              .minus(Duration.ofNanos(previousSettings.getFirstAttemptStartTimeNanos()));
-      Duration timeLeft = settings.getTotalTimeout().minus(timeElapsed).minus(randomDelay);
-
-      // If timeLeft at this point is < 0, the shouldRetry logic will prevent
-      // the attempt from being made as it would exceed the totalTimeout. A negative RPC timeout
-      // will result in a deadline in the past, which should will always fail prior to making a
-      // network call.
-      newRpcTimeout = Math.min(newRpcTimeout, timeLeft.toMillis());
-    }
-
-    return TimedAttemptSettings.newBuilder()
-        .setGlobalSettings(previousSettings.getGlobalSettings())
-        .setRetryDelay(Duration.ofMillis(newRetryDelay))
-        .setRpcTimeout(Duration.ofMillis(newRpcTimeout))
-        .setRandomizedRetryDelay(randomDelay)
-        .setAttemptCount(previousSettings.getAttemptCount() + 1)
-        .setOverallAttemptCount(previousSettings.getOverallAttemptCount() + 1)
-        .setFirstAttemptStartTimeNanos(previousSettings.getFirstAttemptStartTimeNanos())
-        .build();
-  }
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}. The implementation increments the current
-   * attempt count and uses randomized exponential backoff factor for calculating next attempt
-   * execution time.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes
-   * @param previousSettings previous attempt settings
-   * @return next attempt settings
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      RetryingContext context, TimedAttemptSettings previousSettings) {
-    // The RetrySettings from the context are not used here, as they have already been set as the
-    // global settings during the creation of the initial attempt.
-    return createNextAttempt(previousSettings);
-  }
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @return {@code true} if {@code nextAttemptSettings} does not exceed either maxAttempts limit or
-   *     totalTimeout limit, or {@code false} otherwise
-   */
-  @Override
-  public boolean shouldRetry(TimedAttemptSettings nextAttemptSettings) {
-    RetrySettings globalSettings = nextAttemptSettings.getGlobalSettings();
-
-    int maxAttempts = globalSettings.getMaxAttempts();
-    long totalTimeout = globalSettings.getTotalTimeout().toNanos();
-
-    // If total timeout and maxAttempts is not set then do not attempt retry.
-    if (totalTimeout == 0 && maxAttempts == 0) {
-      return false;
-    }
-
-    long totalTimeSpentNanos =
-        clock.nanoTime()
-            - nextAttemptSettings.getFirstAttemptStartTimeNanos()
-            + nextAttemptSettings.getRandomizedRetryDelay().toNanos();
-
-    // If totalTimeout limit is defined, check that it hasn't been crossed.
-    //
-    // Note: if the potential time spent is exactly equal to the totalTimeout,
-    // the attempt will still be allowed. This might not be desired, but if we
-    // enforce it, it could have potentially negative side effects on LRO polling.
-    // Specifically, if a polling retry attempt is denied, the LRO is canceled, and
-    // if a polling retry attempt is denied because its delay would *reach* the
-    // totalTimeout, the LRO would be canceled prematurely. The problem here is that
-    // totalTimeout doubles as the polling threshold and also the time limit for an
-    // operation to finish.
-    if (totalTimeout > 0 && totalTimeSpentNanos > totalTimeout) {
-      return false;
-    }
-
-    // If maxAttempts limit is defined, check that it hasn't been crossed
-    if (maxAttempts > 0 && nextAttemptSettings.getAttemptCount() >= maxAttempts) {
-      return false;
-    }
-
-    // No limits crossed
-    return true;
-  }
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes. Ignored by this implementation.
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @return {@code true} if {@code nextAttemptSettings} does not exceed either maxAttempts limit or
-   *     totalTimeout limit, or {@code false} otherwise
-   */
-  @Override
-  public boolean shouldRetry(RetryingContext context, TimedAttemptSettings nextAttemptSettings) {
-    // The RetrySettings from the context are not used here, as they have already been set as the
-    // global settings during the creation of the initial attempt.
-    return shouldRetry(nextAttemptSettings);
-  }
-
-  // Injecting Random is not possible here, as Random does not provide nextLong(long bound) method
-  protected long nextRandomLong(long bound) {
-    return bound > 0 && globalSettings.isJittered() // Jitter check needed for testing purposes.
-        ? ThreadLocalRandom.current().nextLong(bound)
-        : bound;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/NonCancellableFuture.java b/gax/src/main/java/com/google/api/gax/retrying/NonCancellableFuture.java
deleted file mode 100644
index 19e3587a4..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/NonCancellableFuture.java
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.InternalApi;
-
-/**
- * A future which cannot be cancelled from the external package.
- *
- * <p>For internal use, public for technical reasons.
- *
- * @param <ResponseT> future response type
- */
-@InternalApi
-public final class NonCancellableFuture<ResponseT> extends AbstractApiFuture<ResponseT> {
-  @Override
-  public boolean cancel(boolean mayInterruptIfRunning) {
-    return false;
-  }
-
-  void cancelPrivately() {
-    super.cancel(false);
-  }
-
-  boolean setPrivately(ResponseT value) {
-    return super.set(value);
-  }
-
-  boolean setExceptionPrivately(Throwable throwable) {
-    return super.setException(throwable);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/NoopRetryingContext.java b/gax/src/main/java/com/google/api/gax/retrying/NoopRetryingContext.java
deleted file mode 100644
index 840918ed3..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/NoopRetryingContext.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-// TODO(igorbernstein2): Remove this class once RetryingExecutor#createFuture(Callable) is
-// deprecated and removed.
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.api.gax.tracing.BaseApiTracer;
-import java.util.Set;
-import javax.annotation.Nonnull;
-
-/**
- * Backwards compatibility class to aid in transition to adding operation state to {@link
- * RetryingFuture} implementations.
- */
-class NoopRetryingContext implements RetryingContext {
-  public static RetryingContext create() {
-    return new NoopRetryingContext();
-  }
-
-  /** {@inheritDoc} */
-  @Nonnull
-  @Override
-  public ApiTracer getTracer() {
-    return BaseApiTracer.getInstance();
-  }
-
-  @Override
-  public RetrySettings getRetrySettings() {
-    return null;
-  }
-
-  @Override
-  public Set<Code> getRetryableCodes() {
-    return null;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/PollException.java b/gax/src/main/java/com/google/api/gax/retrying/PollException.java
deleted file mode 100644
index 4534e100c..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/PollException.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-/**
- * {@code PollException} is thrown when polling algorithm exceeds total timeout or total number of
- * attempts.
- */
-public class PollException extends RuntimeException {
-
-  private static final long serialVersionUID = -3666617975087303999L;
-
-  /** Constructs a {@code PollException} with no specified detail message. */
-  public PollException() {
-    super();
-  }
-
-  /**
-   * Constructs a new poll timeout exception with the specified detail message.
-   *
-   * @param message the detail message
-   */
-  public PollException(String message) {
-    super(message);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithm.java
deleted file mode 100644
index 53363f37a..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithm.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * Same as {@link ResultRetryAlgorithmWithContext}, but without methods that accept a {@link
- * RetryingContext}. Use {@link ResultRetryAlgorithmWithContext} instead of this interface when
- * possible.
- */
-public interface ResultRetryAlgorithm<ResponseT> {
-  /**
-   * Same as {@link ResultRetryAlgorithmWithContext#createNextAttempt(RetryingContext, Throwable,
-   * Object, TimedAttemptSettings)}, but without a {@link RetryingContext}.
-   *
-   * <p>Use {@link ResultRetryAlgorithmWithContext#createNextAttempt(RetryingContext, Throwable,
-   * Object, TimedAttemptSettings)} instead of this method when possible.
-   */
-  TimedAttemptSettings createNextAttempt(
-      Throwable prevThrowable, ResponseT prevResponse, TimedAttemptSettings prevSettings);
-
-  /**
-   * Same as {@link ResultRetryAlgorithmWithContext#shouldRetry(Throwable, Object)}, but without a
-   * {@link RetryingContext}.
-   *
-   * <p>Use {@link ResultRetryAlgorithmWithContext#shouldRetry(RetryingContext, Throwable, Object)}
-   * instead of this method when possible.
-   */
-  boolean shouldRetry(Throwable prevThrowable, ResponseT prevResponse) throws CancellationException;
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithmWithContext.java b/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithmWithContext.java
deleted file mode 100644
index 2a347b13a..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ResultRetryAlgorithmWithContext.java
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * A result retry algorithm is responsible for the following operations (based on the response
- * returned by the previous attempt or on the thrown exception):
- *
- * <ol>
- *   <li>Accepting a task for retry so another attempt will be made.
- *   <li>Canceling retrying process so the related {@link java.util.concurrent.Future} will be
- *       canceled.
- *   <li>Creating {@link TimedAttemptSettings} for each subsequent retry attempt.
- * </ol>
- *
- * Implementations of this interface receive a {@link RetryingContext} that can contain specific
- * {@link RetrySettings} and retryable codes that should be used to determine the retry behavior.
- *
- * <p>Implementations of this interface must be thread-safe.
- *
- * @param <ResponseT> response type
- */
-public interface ResultRetryAlgorithmWithContext<ResponseT>
-    extends ResultRetryAlgorithm<ResponseT> {
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}.
-   *
-   * @param context the retrying context of this invocation that can be used to determine the
-   *     settings for the next attempt.
-   * @param previousThrowable exception thrown by the previous attempt ({@code null}, if none)
-   * @param previousResponse response returned by the previous attempt
-   * @param previousSettings previous attempt settings
-   */
-  TimedAttemptSettings createNextAttempt(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings);
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param context the retrying context of this invocation that can be used to determine whether
-   *     the call should be retried.
-   * @param previousThrowable exception thrown by the previous attempt ({@code null}, if none)
-   * @param previousResponse response returned by the previous attempt.
-   */
-  boolean shouldRetry(
-      RetryingContext context, Throwable previousThrowable, ResponseT previousResponse)
-      throws CancellationException;
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/RetryAlgorithm.java
deleted file mode 100644
index 16d60d148..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetryAlgorithm.java
+++ /dev/null
@@ -1,267 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.BetaApi;
-import java.util.concurrent.CancellationException;
-
-/**
- * The retry algorithm, which makes decision based either on the thrown exception or the returned
- * response, and the execution time settings of the previous attempt.
- *
- * <p>This class is thread-safe.
- *
- * @param <ResponseT> response type
- */
-public class RetryAlgorithm<ResponseT> {
-  private final ResultRetryAlgorithm<ResponseT> resultAlgorithm;
-  private final TimedRetryAlgorithm timedAlgorithm;
-  private final ResultRetryAlgorithmWithContext<ResponseT> resultAlgorithmWithContext;
-  private final TimedRetryAlgorithmWithContext timedAlgorithmWithContext;
-
-  /**
-   * Creates a new retry algorithm instance, which uses thrown exception or returned response and
-   * timed algorithms to make a decision. The result algorithm has higher priority than the timed
-   * algorithm.
-   *
-   * <p>Instances that are created using this constructor will ignore the {@link RetryingContext}
-   * that is passed in to the retrying methods. Use {@link
-   * #RetryAlgorithm(ResultRetryAlgorithmWithContext, TimedRetryAlgorithmWithContext)} to create an
-   * instance that will respect the {@link RetryingContext}.
-   *
-   * @param resultAlgorithm result algorithm to use
-   * @param timedAlgorithm timed algorithm to use
-   * @deprecated use {@link RetryAlgorithm#RetryAlgorithm(ResultRetryAlgorithmWithContext,
-   *     TimedRetryAlgorithmWithContext)} instead
-   */
-  @Deprecated
-  public RetryAlgorithm(
-      ResultRetryAlgorithm<ResponseT> resultAlgorithm, TimedRetryAlgorithm timedAlgorithm) {
-    this.resultAlgorithm = checkNotNull(resultAlgorithm);
-    this.timedAlgorithm = checkNotNull(timedAlgorithm);
-    this.resultAlgorithmWithContext = null;
-    this.timedAlgorithmWithContext = null;
-  }
-
-  /**
-   * Creates a new retry algorithm instance, which uses thrown exception or returned response and
-   * timed algorithms to make a decision. The result algorithm has higher priority than the timed
-   * algorithm.
-   *
-   * @param resultAlgorithm result algorithm to use
-   * @param timedAlgorithm timed algorithm to use
-   */
-  public RetryAlgorithm(
-      ResultRetryAlgorithmWithContext<ResponseT> resultAlgorithm,
-      TimedRetryAlgorithmWithContext timedAlgorithm) {
-    this.resultAlgorithm = null;
-    this.timedAlgorithm = null;
-    this.resultAlgorithmWithContext = checkNotNull(resultAlgorithm);
-    this.timedAlgorithmWithContext = checkNotNull(timedAlgorithm);
-  }
-
-  /**
-   * Creates a first attempt {@link TimedAttemptSettings}.
-   *
-   * @return first attempt settings
-   * @deprecated use {@link #createFirstAttempt(RetryingContext)} instead
-   */
-  @Deprecated
-  public TimedAttemptSettings createFirstAttempt() {
-    return createFirstAttempt(null);
-  }
-
-  /**
-   * Creates a first attempt {@link TimedAttemptSettings}.
-   *
-   * @param context the {@link RetryingContext} that can be used to get the initial {@link
-   *     RetrySettings}
-   * @return first attempt settings
-   */
-  public TimedAttemptSettings createFirstAttempt(RetryingContext context) {
-    if (timedAlgorithmWithContext != null && context != null) {
-      return timedAlgorithmWithContext.createFirstAttempt(context);
-    }
-    return getTimedAlgorithm().createFirstAttempt();
-  }
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}. This method will return first non-null
-   * value, returned by either result or timed retry algorithms in that particular order.
-   *
-   * @param previousThrowable exception thrown by the previous attempt or null if a result was
-   *     returned instead
-   * @param previousResponse response returned by the previous attempt or null if an exception was
-   *     thrown instead
-   * @param previousSettings previous attempt settings
-   * @return next attempt settings, can be {@code null}, if no there should be no new attempt
-   * @deprecated use {@link #createNextAttempt(RetryingContext, Throwable, Object,
-   *     TimedAttemptSettings)} instead
-   */
-  @Deprecated
-  public TimedAttemptSettings createNextAttempt(
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    return createNextAttempt(null, previousThrowable, previousResponse, previousSettings);
-  }
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}. This method will return first non-null
-   * value, returned by either result or timed retry algorithms in that particular order.
-   *
-   * @param context the {@link RetryingContext} that can be used to determine the {@link
-   *     RetrySettings} for the next attempt
-   * @param previousThrowable exception thrown by the previous attempt or null if a result was
-   *     returned instead
-   * @param previousResponse response returned by the previous attempt or null if an exception was
-   *     thrown instead
-   * @param previousSettings previous attempt settings
-   * @return next attempt settings, can be {@code null}, if there should be no new attempt
-   */
-  public TimedAttemptSettings createNextAttempt(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    // a small optimization that avoids calling relatively heavy methods
-    // like timedAlgorithm.createNextAttempt(), when it is not necessary.
-    if (!shouldRetryBasedOnResult(context, previousThrowable, previousResponse)) {
-      return null;
-    }
-
-    TimedAttemptSettings newSettings =
-        createNextAttemptBasedOnResult(
-            context, previousThrowable, previousResponse, previousSettings);
-    if (newSettings == null) {
-      newSettings = createNextAttemptBasedOnTiming(context, previousSettings);
-    }
-    return newSettings;
-  }
-
-  private TimedAttemptSettings createNextAttemptBasedOnResult(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    if (resultAlgorithmWithContext != null && context != null) {
-      return resultAlgorithmWithContext.createNextAttempt(
-          context, previousThrowable, previousResponse, previousSettings);
-    }
-    return getResultAlgorithm()
-        .createNextAttempt(previousThrowable, previousResponse, previousSettings);
-  }
-
-  private TimedAttemptSettings createNextAttemptBasedOnTiming(
-      RetryingContext context, TimedAttemptSettings previousSettings) {
-    if (timedAlgorithmWithContext != null && context != null) {
-      return timedAlgorithmWithContext.createNextAttempt(context, previousSettings);
-    }
-    return getTimedAlgorithm().createNextAttempt(previousSettings);
-  }
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param previousThrowable exception thrown by the previous attempt or null if a result was
-   *     returned instead
-   * @param previousResponse response returned by the previous attempt or null if an exception was
-   *     thrown instead
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @throws CancellationException if the retrying process should be canceled
-   * @return {@code true} if another attempt should be made, or {@code false} otherwise
-   * @deprecated use {@link #shouldRetry(RetryingContext, Throwable, Object, TimedAttemptSettings)}
-   *     instead
-   */
-  @Deprecated
-  public boolean shouldRetry(
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings nextAttemptSettings)
-      throws CancellationException {
-    return shouldRetry(null, previousThrowable, previousResponse, nextAttemptSettings);
-  }
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param context the {@link RetryingContext} that can be used to determine whether another
-   *     attempt should be made
-   * @param previousThrowable exception thrown by the previous attempt or null if a result was
-   *     returned instead
-   * @param previousResponse response returned by the previous attempt or null if an exception was
-   *     thrown instead
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @throws CancellationException if the retrying process should be cancelled
-   * @return {@code true} if another attempt should be made, or {@code false} otherwise
-   */
-  public boolean shouldRetry(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings nextAttemptSettings)
-      throws CancellationException {
-    return shouldRetryBasedOnResult(context, previousThrowable, previousResponse)
-        && shouldRetryBasedOnTiming(context, nextAttemptSettings);
-  }
-
-  boolean shouldRetryBasedOnResult(
-      RetryingContext context, Throwable previousThrowable, ResponseT previousResponse) {
-    if (resultAlgorithmWithContext != null && context != null) {
-      return resultAlgorithmWithContext.shouldRetry(context, previousThrowable, previousResponse);
-    }
-    return getResultAlgorithm().shouldRetry(previousThrowable, previousResponse);
-  }
-
-  private boolean shouldRetryBasedOnTiming(
-      RetryingContext context, TimedAttemptSettings nextAttemptSettings) {
-    if (nextAttemptSettings == null) {
-      return false;
-    }
-    if (timedAlgorithmWithContext != null && context != null) {
-      return timedAlgorithmWithContext.shouldRetry(context, nextAttemptSettings);
-    }
-    return getTimedAlgorithm().shouldRetry(nextAttemptSettings);
-  }
-
-  @BetaApi("Surface for inspecting the a RetryAlgorithm is not yet stable")
-  public ResultRetryAlgorithm<ResponseT> getResultAlgorithm() {
-    return resultAlgorithmWithContext != null ? resultAlgorithmWithContext : resultAlgorithm;
-  }
-
-  @BetaApi("Surface for inspecting the a RetryAlgorithm is not yet stable")
-  public TimedRetryAlgorithm getTimedAlgorithm() {
-    return timedAlgorithmWithContext != null ? timedAlgorithmWithContext : timedAlgorithm;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetrySettings.java b/gax/src/main/java/com/google/api/gax/retrying/RetrySettings.java
deleted file mode 100644
index f5722f1ae..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetrySettings.java
+++ /dev/null
@@ -1,375 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.BetaApi;
-import com.google.auto.value.AutoValue;
-import com.google.common.annotations.VisibleForTesting;
-import java.io.Serializable;
-import org.threeten.bp.Duration;
-
-/**
- * Holds the parameters for <b>retry</b> or <b>poll</b> logic with jitter, timeout and exponential
- * backoff. Actual implementation of the logic is elsewhere.
- *
- * <p>The intent of these settings is to be used with a call to a remote server, which could either
- * fail (and return an error code) or not respond (and cause a timeout). When there is a failure or
- * timeout, the logic should keep trying until the total timeout has passed.
- *
- * <p>The "total timeout" and "max attempts" settings have ultimate control over how long the logic
- * should keep trying the remote call until it gives up completely. The remote call will be retried
- * until one of those thresholds is crossed. To avoid unbounded rpc calls, it is required to
- * configure one of those settings. If both are 0, then retries will be disabled. The other settings
- * are considered more advanced.
- *
- * <p>Retry delay and timeout start at specific values, and are tracked separately from each other.
- * The very first call (before any retries) will use the initial timeout.
- *
- * <p>If the last remote call is a failure, then the retrier will wait for the current retry delay
- * before attempting another call, and then the retry delay will be multiplied by the retry delay
- * multiplier for the next failure. The timeout will not be affected, except in the case where the
- * timeout would result in a deadline past the total timeout; in that circumstance, a new timeout
- * value is computed which will terminate the call when the total time is up.
- *
- * <p>If the last remote call is a timeout, then the retrier will compute a new timeout and make
- * another call. The new timeout is computed by multiplying the current timeout by the timeout
- * multiplier, but if that results in a deadline after the total timeout, then a new timeout value
- * is computed which will terminate the call when the total time is up.
- *
- * <p>Server streaming RPCs interpret RPC timeouts a bit differently. For server streaming RPCs, the
- * RPC timeout gets converted into a wait timeout {@link
- * com.google.api.gax.rpc.ApiCallContext#withStreamWaitTimeout(Duration)}.
- */
-@AutoValue
-public abstract class RetrySettings implements Serializable {
-
-  private static final long serialVersionUID = 8258475264439710899L;
-
-  /**
-   * TotalTimeout has ultimate control over how long the logic should keep trying the remote call
-   * until it gives up completely. The higher the total timeout, the more retries can be attempted.
-   * The default value is {@code Duration.ZERO}.
-   */
-  public abstract Duration getTotalTimeout();
-
-  /**
-   * InitialRetryDelay controls the delay before the first retry. Subsequent retries will use this
-   * value adjusted according to the RetryDelayMultiplier. The default value is {@code
-   * Duration.ZERO}.
-   */
-  public abstract Duration getInitialRetryDelay();
-
-  /**
-   * RetryDelayMultiplier controls the change in retry delay. The retry delay of the previous call
-   * is multiplied by the RetryDelayMultiplier to calculate the retry delay for the next call. The
-   * default value is {@code 1.0}.
-   */
-  public abstract double getRetryDelayMultiplier();
-
-  /**
-   * MaxRetryDelay puts a limit on the value of the retry delay, so that the RetryDelayMultiplier
-   * can't increase the retry delay higher than this amount. The default value is {@code
-   * Duration.ZERO}.
-   */
-  public abstract Duration getMaxRetryDelay();
-
-  /**
-   * MaxAttempts defines the maximum number of attempts to perform. The default value is {@code 0}.
-   * If this value is greater than 0, and the number of attempts reaches this limit, the logic will
-   * give up retrying even if the total retry time is still lower than TotalTimeout.
-   */
-  public abstract int getMaxAttempts();
-
-  /**
-   * Jitter determines if the delay time should be randomized. In most cases, if jitter is set to
-   * {@code true} the actual delay time is calculated in the following way:
-   *
-   * <pre>{@code actualDelay = rand_between(0, min(maxRetryDelay, delay))}</pre>
-   *
-   * The default value is {@code true}.
-   *
-   * @deprecated Retries always jitter.
-   */
-  @Deprecated
-  @VisibleForTesting
-  public abstract boolean isJittered();
-
-  /**
-   * InitialRpcTimeout controls the timeout for the initial RPC. Subsequent calls will use this
-   * value adjusted according to the RpcTimeoutMultiplier. The default value is {@code
-   * Duration.ZERO}.
-   */
-  public abstract Duration getInitialRpcTimeout();
-
-  /**
-   * RpcTimeoutMultiplier controls the change in RPC timeout. The timeout of the previous call is
-   * multiplied by the RpcTimeoutMultiplier to calculate the timeout for the next call. The default
-   * value is {@code 1.0}.
-   */
-  public abstract double getRpcTimeoutMultiplier();
-
-  /**
-   * MaxRpcTimeout puts a limit on the value of the RPC timeout, so that the RpcTimeoutMultiplier
-   * can't increase the RPC timeout higher than this amount. The default value is {@code
-   * Duration.ZERO}.
-   */
-  public abstract Duration getMaxRpcTimeout();
-
-  public static Builder newBuilder() {
-    return new AutoValue_RetrySettings.Builder()
-        .setTotalTimeout(Duration.ZERO)
-        .setInitialRetryDelay(Duration.ZERO)
-        .setRetryDelayMultiplier(1.0)
-        .setMaxRetryDelay(Duration.ZERO)
-        .setMaxAttempts(0)
-        .setJittered(true)
-        .setInitialRpcTimeout(Duration.ZERO)
-        .setRpcTimeoutMultiplier(1.0)
-        .setMaxRpcTimeout(Duration.ZERO);
-  }
-
-  public abstract Builder toBuilder();
-
-  /**
-   * A base builder class for {@link RetrySettings}. See the class documentation of {@link
-   * RetrySettings} for a description of the different values that can be set.
-   */
-  @AutoValue.Builder
-  public abstract static class Builder {
-
-    /**
-     * TotalTimeout has ultimate control over how long the logic should keep trying the remote call
-     * until it gives up completely. The higher the total timeout, the more retries can be
-     * attempted. The default value is {@code Duration.ZERO}.
-     */
-    public abstract Builder setTotalTimeout(Duration totalTimeout);
-
-    /**
-     * InitialRetryDelay controls the delay before the first retry. Subsequent retries will use this
-     * value adjusted according to the RetryDelayMultiplier. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Builder setInitialRetryDelay(Duration initialDelay);
-
-    /**
-     * RetryDelayMultiplier controls the change in retry delay. The retry delay of the previous call
-     * is multiplied by the RetryDelayMultiplier to calculate the retry delay for the next call. The
-     * default value is {@code 1.0}.
-     */
-    public abstract Builder setRetryDelayMultiplier(double multiplier);
-
-    /**
-     * MaxRetryDelay puts a limit on the value of the retry delay, so that the RetryDelayMultiplier
-     * can't increase the retry delay higher than this amount. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Builder setMaxRetryDelay(Duration maxDelay);
-
-    /**
-     * MaxAttempts defines the maximum number of attempts to perform. The default value is {@code
-     * 0}. If this value is greater than 0, and the number of attempts reaches this limit, the logic
-     * will give up retrying even if the total retry time is still lower than TotalTimeout.
-     */
-    public abstract Builder setMaxAttempts(int maxAttempts);
-
-    /**
-     * Jitter determines if the delay time should be randomized. If jitter is set to {@code true}
-     * the actual delay time is calculated in the following way:
-     *
-     * <pre>{@code actualDelay = rand_between(0, min(maxRetryDelay, exponentialDelay))}</pre>
-     *
-     * The default value is {@code true}, and this method will be a no-op soon.
-     *
-     * @deprecated Retries always jitter.
-     */
-    @Deprecated
-    @VisibleForTesting
-    public abstract Builder setJittered(boolean jittered);
-
-    /**
-     * InitialRpcTimeout controls the timeout for the initial RPC. Subsequent calls will use this
-     * value adjusted according to the RpcTimeoutMultiplier. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Builder setInitialRpcTimeout(Duration initialTimeout);
-
-    /**
-     * See the class documentation of {@link RetrySettings} for a description of what this value
-     * does. The default value is {@code 1.0}.
-     */
-    public abstract Builder setRpcTimeoutMultiplier(double multiplier);
-
-    /**
-     * MaxRpcTimeout puts a limit on the value of the RPC timeout, so that the RpcTimeoutMultiplier
-     * can't increase the RPC timeout higher than this amount. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Builder setMaxRpcTimeout(Duration maxTimeout);
-
-    /**
-     * TotalTimeout has ultimate control over how long the logic should keep trying the remote call
-     * until it gives up completely. The higher the total timeout, the more retries can be
-     * attempted. The default value is {@code Duration.ZERO}.
-     */
-    public abstract Duration getTotalTimeout();
-
-    /**
-     * InitialRetryDelay controls the delay before the first retry. Subsequent retries will use this
-     * value adjusted according to the RetryDelayMultiplier. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Duration getInitialRetryDelay();
-
-    /**
-     * RetryDelayMultiplier controls the change in retry delay. The retry delay of the previous call
-     * is multiplied by the RetryDelayMultiplier to calculate the retry delay for the next call. The
-     * default value is {@code 1.0}.
-     */
-    public abstract double getRetryDelayMultiplier();
-
-    /**
-     * MaxAttempts defines the maximum number of attempts to perform. The default value is {@code
-     * 0}. If this value is greater than 0, and the number of attempts reaches this limit, the logic
-     * will give up retrying even if the total retry time is still lower than TotalTimeout.
-     */
-    public abstract int getMaxAttempts();
-
-    /**
-     * Jitter determines if the delay time should be randomized. In most cases, if jitter is set to
-     * {@code true} the actual delay time is calculated in the following way:
-     *
-     * <pre>{@code actualDelay = rand_between(0, min(maxRetryDelay, exponentialDelay))}</pre>
-     *
-     * The default value is {@code true}.
-     */
-    public abstract boolean isJittered();
-
-    /**
-     * MaxRetryDelay puts a limit on the value of the retry delay, so that the RetryDelayMultiplier
-     * can't increase the retry delay higher than this amount. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Duration getMaxRetryDelay();
-
-    /**
-     * InitialRpcTimeout controls the timeout for the initial RPC. Subsequent calls will use this
-     * value adjusted according to the RpcTimeoutMultiplier. The default value is {@code
-     * Duration.ZERO}.
-     */
-    public abstract Duration getInitialRpcTimeout();
-
-    /**
-     * See the class documentation of {@link RetrySettings} for a description of what this value
-     * does. The default value is {@code 1.0}.
-     */
-    public abstract double getRpcTimeoutMultiplier();
-
-    /**
-     * MaxRpcTimeout puts a limit on the value of the RPC timeout, so that the RpcTimeoutMultiplier
-     * can't increase the RPC timeout higher than this amount.
-     */
-    public abstract Duration getMaxRpcTimeout();
-
-    /**
-     * Configures the timeout settings with the given timeout such that the logical call will take
-     * no longer than the given timeout and each RPC attempt will use only the time remaining in the
-     * logical call as a timeout.
-     *
-     * <p>Using this method in conjunction with individual {@link RetrySettings} timeout field
-     * setters is not advised, because only the order in which they are invoked determines which
-     * setter is respected.
-     */
-    @BetaApi
-    public Builder setLogicalTimeout(Duration timeout) {
-      return setRpcTimeoutMultiplier(1)
-          .setInitialRpcTimeout(timeout)
-          .setMaxRpcTimeout(timeout)
-          .setTotalTimeout(timeout);
-    }
-
-    abstract RetrySettings autoBuild();
-
-    public RetrySettings build() {
-      RetrySettings params = autoBuild();
-      if (params.getTotalTimeout().toMillis() < 0) {
-        throw new IllegalStateException("total timeout must not be negative");
-      }
-      if (params.getInitialRetryDelay().toMillis() < 0) {
-        throw new IllegalStateException("initial retry delay must not be negative");
-      }
-      if (params.getRetryDelayMultiplier() < 1.0) {
-        throw new IllegalStateException("retry delay multiplier must be at least 1");
-      }
-      if (params.getMaxRetryDelay().compareTo(params.getInitialRetryDelay()) < 0) {
-        throw new IllegalStateException("max retry delay must not be shorter than initial delay");
-      }
-      if (params.getMaxAttempts() < 0) {
-        throw new IllegalStateException("max attempts must be non-negative");
-      }
-      if (params.getInitialRpcTimeout().toMillis() < 0) {
-        throw new IllegalStateException("initial rpc timeout must not be negative");
-      }
-      if (params.getMaxRpcTimeout().compareTo(params.getInitialRpcTimeout()) < 0) {
-        throw new IllegalStateException("max rpc timeout must not be shorter than initial timeout");
-      }
-      if (params.getRpcTimeoutMultiplier() < 1.0) {
-        throw new IllegalStateException("rpc timeout multiplier must be at least 1");
-      }
-      return params;
-    }
-
-    public RetrySettings.Builder merge(RetrySettings.Builder newSettings) {
-      if (newSettings.getTotalTimeout() != null) {
-        setTotalTimeout(newSettings.getTotalTimeout());
-      }
-      if (newSettings.getInitialRetryDelay() != null) {
-        setInitialRetryDelay(newSettings.getInitialRetryDelay());
-      }
-      if (newSettings.getRetryDelayMultiplier() >= 1) {
-        setRetryDelayMultiplier(newSettings.getRetryDelayMultiplier());
-      }
-      if (newSettings.getMaxRetryDelay() != null) {
-        setMaxRetryDelay(newSettings.getMaxRetryDelay());
-      }
-      setMaxAttempts(newSettings.getMaxAttempts());
-      setJittered(newSettings.isJittered());
-      if (newSettings.getInitialRpcTimeout() != null) {
-        setInitialRpcTimeout(newSettings.getInitialRpcTimeout());
-      }
-      if (newSettings.getRpcTimeoutMultiplier() >= 1) {
-        setRpcTimeoutMultiplier(newSettings.getRpcTimeoutMultiplier());
-      }
-      if (newSettings.getMaxRpcTimeout() != null) {
-        setMaxRpcTimeout(newSettings.getMaxRpcTimeout());
-      }
-      return this;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetryingContext.java b/gax/src/main/java/com/google/api/gax/retrying/RetryingContext.java
deleted file mode 100644
index 6db53c4e2..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetryingContext.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.tracing.ApiTracer;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * Context for a retryable operation.
- *
- * <p>It provides state to individual {@link RetryingFuture}s via the {@link RetryingExecutor}.
- */
-@BetaApi("The surface for passing per operation state is not yet stable")
-public interface RetryingContext {
-  /** Returns the {@link ApiTracer} associated with the current operation. */
-  @Nonnull
-  ApiTracer getTracer();
-
-  /**
-   * Returns the {@link RetrySettings} to use with this context, or <code>null</code> if the default
-   * {@link RetrySettings} should be used.
-   */
-  @Nullable
-  RetrySettings getRetrySettings();
-
-  /**
-   * Returns the retryable codes to use with this context, or <code>null</code> if the default
-   * retryable codes should be used.
-   */
-  @Nullable
-  Set<StatusCode.Code> getRetryableCodes();
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutor.java b/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutor.java
deleted file mode 100644
index e8bab994a..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutor.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.ApiFuture;
-import java.util.concurrent.Callable;
-
-/**
- * A retrying executor is responsible for the following operations:
- *
- * <ol>
- *   <li>Creating first attempt {@link RetryingFuture}, which acts as a facade, hiding from client
- *       code the actual execution of scheduled retry attempts.
- *   <li>Executing the actual {@link Callable} in a retriable context.
- * </ol>
- *
- * This interface is for internal/advanced use only.
- *
- * @param <ResponseT> response type
- */
-public interface RetryingExecutor<ResponseT> {
-  /**
-   * Creates the {@link RetryingFuture}, which is a facade, returned to the client code to wait for
-   * any retriable operation to complete.
-   *
-   * @param callable the actual callable, which should be executed in a retriable context
-   * @return retrying future facade
-   */
-  RetryingFuture<ResponseT> createFuture(Callable<ResponseT> callable);
-
-  /**
-   * Submits an attempt for execution. A typical implementation will either try to execute the
-   * attempt in the current thread or schedule it for an execution, using some sort of async
-   * execution service.
-   *
-   * @param retryingFuture the future previously returned by {@link #createFuture(Callable)} and
-   *     reused for each subsequent attempt of same operation.
-   * @return submitted attempt future
-   */
-  ApiFuture<ResponseT> submit(RetryingFuture<ResponseT> retryingFuture);
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutorWithContext.java b/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutorWithContext.java
deleted file mode 100644
index f19ba5607..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetryingExecutorWithContext.java
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import java.util.concurrent.Callable;
-import javax.annotation.Nonnull;
-
-/**
- * A {@link RetryingExecutor} that accepts a per-operation context.
- *
- * @see RetryingExecutor
- */
-// TODO(igorbernstein2): Consider replacing this with a default implementation in RetryingExecutor
-// once support for java 7 is dropped
-@BetaApi("The surface for per invocation state is unstable and will probably change in the future")
-@InternalExtensionOnly
-public interface RetryingExecutorWithContext<ResponseT> extends RetryingExecutor<ResponseT> {
-  RetryingFuture<ResponseT> createFuture(
-      @Nonnull Callable<ResponseT> callable, @Nonnull RetryingContext context);
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/RetryingFuture.java b/gax/src/main/java/com/google/api/gax/retrying/RetryingFuture.java
deleted file mode 100644
index 86b16eac6..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/RetryingFuture.java
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.ApiFuture;
-import java.util.concurrent.Callable;
-
-/**
- * Represents a retrying future. This is a facade hiding all the complications of an
- * asynchronous/synchronous execution of a retriable task.
- *
- * <p>This interface is for advanced/internal use only.
- *
- * @param <ResponseT> response type
- */
-public interface RetryingFuture<ResponseT> extends ApiFuture<ResponseT> {
-  /**
-   * Sets the attempt in a form of a future. This future represents a concrete retry attempt,
-   * potentially scheduled for execution in a some form of {@link
-   * java.util.concurrent.ScheduledExecutorService}, or an already completed future if the attempts
-   * are executed synchronously.
-   *
-   * @param attemptFuture the attempt future
-   */
-  void setAttemptFuture(ApiFuture<ResponseT> attemptFuture);
-
-  /** Returns callable tracked by this future. */
-  Callable<ResponseT> getCallable();
-
-  /** Returns current (active) attempt settings. */
-  TimedAttemptSettings getAttemptSettings();
-
-  /**
-   * Returns latest completed attempt result or {@code null} if the first attempt hasn't completed
-   * yet.
-   *
-   * <p>This method is for internal/advanced use only.
-   *
-   * <p>If not null, the returned value is guaranteed to be an already completed future, so {@link
-   * ApiFuture#isDone()} will always be {@code true} and {@link ApiFuture#get()} will always be
-   * non-blocking.
-   *
-   * <p>In case if the whole retrying future is completed, this method returns the same result as
-   * the retrying future itself.
-   *
-   * <p>The number of attempt results may be (and usually is) lower than the number of actual
-   * attempts, since only a completed attempt has a result and not all attempts complete (some of
-   * the service attempts, needed for proper execution of the actual attempts).
-   *
-   * <p>For each execution the following invariants hold:
-   *
-   * <ul>
-   *   <li>If the first attempt hasn't completed yet, this method returns {@code null}.
-   *   <li>Right after completion of each attempt this method starts returning a new already
-   *       completed future, which represents the result of the latest completed attempt.
-   *   <li>If it was the last attempt, the events happen in the following order: 1) the attempt
-   *       future completes; 2) the whole retrying future completes; 3) this method starts returning
-   *       a new already completed future, which represents the result of the last completed
-   *       attempt.
-   *   <li>After completion of the whole retrying future this method always returns exactly same
-   *       future object.
-   * </ul>
-   */
-  ApiFuture<ResponseT> peekAttemptResult();
-
-  /**
-   * Returns the current (active on the moment of the execution of this method) attempt result
-   * future, allowing to track progress of the retrying future execution.
-   *
-   * <p>Adding direct executor (same thread) callbacks to the future returned by this method is
-   * strongly not recommended, since the future is resolved under retrying future's internal lock
-   * and may affect the whole retrying process. Adding separate thread callbacks is ok.
-   *
-   * <p>This method is for internal/advanced use only.
-   *
-   * <p>The returned future completes right after the corresponding attempt which it tracks, so
-   * calling {@link ApiFuture#get()} is potentially a blocking operation. This method returns
-   * exactly same future object until it completes (meaning that the corresponding attempt has
-   * completed). If there is another attempt made after completion of the current attempt, the
-   * subsequent call to this method will return a new future which will track the new attempt.
-   *
-   * <p>In case if the whole retrying future is completed, this method returns the same result as
-   * the retrying future itself.
-   *
-   * <p>The returned future is non-cancellable, so calling {@link ApiFuture#cancel(boolean)} will
-   * have no effect and will always return {@code false}.
-   *
-   * <p>The number of attempt results may be (and usually is) lower than the number of actual
-   * attempts, since only a completed attempt has a result and not all attempts complete (some of
-   * the service attempts, needed for proper execution of the actual attempts).
-   *
-   * <p>For each execution the following invariants hold:
-   *
-   * <ul>
-   *   <li>The future returned by this method completes soon after the attempt it tracks.
-   *   <li>If it was the last attempt, the futures complete in the following order: 1) the attempt
-   *       future; 2) the whole retrying future; 3) the attempt result future returned by this
-   *       method.
-   *   <li>After completion of the whole retrying future this method always returns exactly same
-   *       future object.
-   * </ul>
-   */
-  ApiFuture<ResponseT> getAttemptResult();
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ScheduledRetryingExecutor.java b/gax/src/main/java/com/google/api/gax/retrying/ScheduledRetryingExecutor.java
deleted file mode 100644
index b6ee0a0c1..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ScheduledRetryingExecutor.java
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
-import com.google.api.core.ListenableFutureToApiFuture;
-import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.ListeningScheduledExecutorService;
-import com.google.common.util.concurrent.MoreExecutors;
-import java.util.concurrent.Callable;
-import java.util.concurrent.RejectedExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-
-/**
- * The retry executor which uses {@link ScheduledExecutorService} to schedule an attempt tasks.
- *
- * <p>This implementation does not manage the lifecycle of the underlying {@link
- * ScheduledExecutorService}, so it should be managed outside of this class (like calling the {@link
- * ScheduledExecutorService#shutdown()} when the pool is not needed anymore). In a typical usage
- * pattern there are usually multiple instances of this class sharing same instance of the
- * underlying {@link ScheduledExecutorService}.
- *
- * <p>This class is thread-safe.
- *
- * @param <ResponseT> response type
- */
-public class ScheduledRetryingExecutor<ResponseT>
-    implements RetryingExecutorWithContext<ResponseT> {
-
-  private final RetryAlgorithm<ResponseT> retryAlgorithm;
-  private final ListeningScheduledExecutorService scheduler;
-
-  /**
-   * Creates a new scheduled retry executor, which will be using {@code scheduler} for actual
-   * attempts scheduling and {@code retryAlgorithm} for retrying strategy.
-   *
-   * @param retryAlgorithm retry algorithm to use
-   * @param scheduler scheduler
-   */
-  public ScheduledRetryingExecutor(
-      RetryAlgorithm<ResponseT> retryAlgorithm, ScheduledExecutorService scheduler) {
-    this.retryAlgorithm = retryAlgorithm;
-    this.scheduler = MoreExecutors.listeningDecorator(scheduler);
-  }
-
-  /**
-   * Creates a {@link RetryingFuture}, which is a facade, returned to the client code to wait for
-   * any retriable operation to complete. The returned future is bounded to {@code this} executor
-   * instance.
-   *
-   * @param callable the actual callable, which should be executed in a retriable context
-   * @return retrying future facade
-   */
-  @Override
-  public RetryingFuture<ResponseT> createFuture(Callable<ResponseT> callable) {
-    return createFuture(callable, NoopRetryingContext.create());
-  }
-
-  /**
-   * Creates a {@link RetryingFuture}, which is a facade, returned to the client code to wait for
-   * any retriable operation to complete. The returned future is bounded to {@code this} executor
-   * instance.
-   *
-   * @param callable the actual callable, which should be executed in a retriable context
-   * @param context the context for this operation
-   * @return retrying future facade
-   */
-  @BetaApi("The surface for passing per operation state is not yet stable")
-  @Override
-  public RetryingFuture<ResponseT> createFuture(
-      Callable<ResponseT> callable, RetryingContext context) {
-    return new CallbackChainRetryingFuture<>(callable, retryAlgorithm, this, context);
-  }
-
-  /**
-   * Submits an attempt for execution in a different thread.
-   *
-   * @param retryingFuture the future previously returned by {@link #createFuture(Callable,
-   *     RetryingContext)}
-   * @return submitted attempt future
-   */
-  @Override
-  public ApiFuture<ResponseT> submit(RetryingFuture<ResponseT> retryingFuture) {
-    try {
-      ListenableFuture<ResponseT> attemptFuture =
-          scheduler.schedule(
-              retryingFuture.getCallable(),
-              retryingFuture.getAttemptSettings().getRandomizedRetryDelay().toMillis(),
-              TimeUnit.MILLISECONDS);
-      return new ListenableFutureToApiFuture<>(attemptFuture);
-    } catch (RejectedExecutionException e) {
-      return ApiFutures.immediateFailedFuture(e);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/ServerStreamingAttemptException.java b/gax/src/main/java/com/google/api/gax/retrying/ServerStreamingAttemptException.java
deleted file mode 100644
index b54776f0b..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/ServerStreamingAttemptException.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.InternalApi;
-
-/**
- * A wrapper exception thrown by {@code ServerStreamingAttemptCallable} to communicate additional
- * context to the {@link StreamingRetryAlgorithm} and to pass the original cancellation stack trace
- * to {@code RetryingServerStreamingCallable}.
- *
- * <p>For internal use only - public for technical reasons.
- */
-@InternalApi
-public class ServerStreamingAttemptException extends RuntimeException {
-  private final boolean canResume;
-  private final boolean seenResponses;
-
-  public ServerStreamingAttemptException(
-      Throwable cause, boolean canResume, boolean seenResponses) {
-    super(cause.getMessage(), cause);
-    this.canResume = canResume;
-    this.seenResponses = seenResponses;
-  }
-
-  /** If the {@link StreamResumptionStrategy} supports resuming after this error. */
-  public boolean canResume() {
-    return canResume;
-  }
-
-  /**
-   * If the current RPC attempt has seen any streamed messages. This is used as a signal by {@link
-   * StreamingRetryAlgorithm} to reset timers.
-   */
-  public boolean hasSeenResponses() {
-    return seenResponses;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/SimpleStreamResumptionStrategy.java b/gax/src/main/java/com/google/api/gax/retrying/SimpleStreamResumptionStrategy.java
deleted file mode 100644
index 7c5902129..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/SimpleStreamResumptionStrategy.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.common.base.Preconditions;
-
-/**
- * Simplest implementation of a {@link StreamResumptionStrategy} which returns the initial request
- * for unstarted streams.
- */
-public final class SimpleStreamResumptionStrategy<RequestT, ResponseT>
-    implements StreamResumptionStrategy<RequestT, ResponseT> {
-  private boolean seenFirstResponse;
-
-  @Override
-  public StreamResumptionStrategy<RequestT, ResponseT> createNew() {
-    return new SimpleStreamResumptionStrategy<>();
-  }
-
-  @Override
-  public ResponseT processResponse(ResponseT response) {
-    seenFirstResponse = true;
-    return response;
-  }
-
-  @Override
-  public RequestT getResumeRequest(RequestT originalRequest) {
-    Preconditions.checkState(!seenFirstResponse, "Tried to resume an unresumeable stream.");
-    return originalRequest;
-  }
-
-  @Override
-  public boolean canResume() {
-    return !seenFirstResponse;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/StreamResumptionStrategy.java b/gax/src/main/java/com/google/api/gax/retrying/StreamResumptionStrategy.java
deleted file mode 100644
index 227b4b0ce..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/StreamResumptionStrategy.java
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * This is part of the server streaming retry api. Its implementers are responsible for tracking the
- * progress of the stream and calculating a request to resume it in case of an error.
- *
- * <p>Implementations don't have to be threadsafe because all of the calls will be serialized.
- */
-public interface StreamResumptionStrategy<RequestT, ResponseT> {
-
-  /** Creates a new instance of this StreamResumptionStrategy without accumulated state */
-  @Nonnull
-  StreamResumptionStrategy<RequestT, ResponseT> createNew();
-
-  /**
-   * Called by the {@code ServerStreamingAttemptCallable} when a response has been successfully
-   * received. This method accomplishes two goals:
-   *
-   * <ol>
-   *   <li>It allows the strategy implementation to update its internal state so that it can compose
-   *       the resume request
-   *   <li>It allows the strategy to alter the incoming responses to adjust for after resume. For
-   *       example, if the responses are numbered sequentially from the start of the stream, upon
-   *       resume, the strategy could rewrite the messages to continue the sequence from where it
-   *       left off. Please note that all messages (even for the first attempt) will be passed
-   *       through this method.
-   * </ol>
-   */
-  @Nonnull
-  ResponseT processResponse(ResponseT response);
-
-  /**
-   * Called when a stream needs to be restarted, the implementation should generate a request that
-   * will yield a new stream whose first response would come right after the last response received
-   * by processResponse.
-   *
-   * @return A request that can be used to resume the stream.
-   */
-  @Nullable
-  RequestT getResumeRequest(RequestT originalRequest);
-
-  /** If a resume request can be created. */
-  boolean canResume();
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/StreamingRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/StreamingRetryAlgorithm.java
deleted file mode 100644
index 272fe3ba1..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/StreamingRetryAlgorithm.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.InternalApi;
-import java.util.concurrent.CancellationException;
-
-/**
- * The streaming retry algorithm, which makes decision based either on the thrown exception and the
- * execution time settings of the previous attempt. This extends {@link RetryAlgorithm} to take
- * additional information (provided by {@code ServerStreamingAttemptCallable}) into account.
- *
- * <p>This class is thread-safe.
- *
- * <p>Internal use only - public for technical reasons.
- */
-@InternalApi("For internal use only")
-public final class StreamingRetryAlgorithm<ResponseT> extends RetryAlgorithm<ResponseT> {
-
-  /**
-   * Instances that are created using this constructor will ignore the {@link RetryingContext} that
-   * is passed in to the retrying methods. Use {@link
-   * #StreamingRetryAlgorithm(ResultRetryAlgorithmWithContext, TimedRetryAlgorithmWithContext)} to
-   * create an instance that will respect the {@link RetryingContext}.
-   *
-   * @deprecated use {@link #StreamingRetryAlgorithm(ResultRetryAlgorithmWithContext,
-   *     TimedRetryAlgorithmWithContext)} instead
-   */
-  @Deprecated
-  public StreamingRetryAlgorithm(
-      ResultRetryAlgorithm<ResponseT> resultAlgorithm, TimedRetryAlgorithm timedAlgorithm) {
-    super(resultAlgorithm, timedAlgorithm);
-  }
-
-  /**
-   * Creates a {@link StreamingRetryAlgorithm} that will use the settings (if any) in the {@link
-   * RetryingContext} that is passed in to the retrying methods.
-   */
-  public StreamingRetryAlgorithm(
-      ResultRetryAlgorithmWithContext<ResponseT> resultAlgorithm,
-      TimedRetryAlgorithmWithContext timedAlgorithm) {
-    super(resultAlgorithm, timedAlgorithm);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>The attempt settings will be reset if the stream attempt produced any messages.
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-    return createNextAttempt(null, previousThrowable, previousResponse, previousSettings);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>The attempt settings will be reset if the stream attempt produced any messages.
-   */
-  @Override
-  public TimedAttemptSettings createNextAttempt(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings previousSettings) {
-
-    if (previousThrowable instanceof ServerStreamingAttemptException) {
-      ServerStreamingAttemptException attemptException =
-          (ServerStreamingAttemptException) previousThrowable;
-      previousThrowable = previousThrowable.getCause();
-
-      // If we have made progress in the last attempt, then reset the delays
-      if (attemptException.hasSeenResponses()) {
-        previousSettings =
-            createFirstAttempt(context)
-                .toBuilder()
-                .setFirstAttemptStartTimeNanos(previousSettings.getFirstAttemptStartTimeNanos())
-                .setOverallAttemptCount(previousSettings.getOverallAttemptCount())
-                .build();
-      }
-    }
-
-    return super.createNextAttempt(context, previousThrowable, previousResponse, previousSettings);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>Ensures retries are only scheduled if the {@link StreamResumptionStrategy} in the {@code
-   * ServerStreamingAttemptCallable} supports it.
-   */
-  @Override
-  public boolean shouldRetry(
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings nextAttemptSettings)
-      throws CancellationException {
-    return shouldRetry(null, previousThrowable, previousResponse, nextAttemptSettings);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>Schedules retries only if the {@link StreamResumptionStrategy} in the {@code
-   * ServerStreamingAttemptCallable} supports it.
-   */
-  @Override
-  public boolean shouldRetry(
-      RetryingContext context,
-      Throwable previousThrowable,
-      ResponseT previousResponse,
-      TimedAttemptSettings nextAttemptSettings)
-      throws CancellationException {
-
-    // Unwrap
-    if (previousThrowable instanceof ServerStreamingAttemptException) {
-      ServerStreamingAttemptException attemptException =
-          (ServerStreamingAttemptException) previousThrowable;
-      previousThrowable = previousThrowable.getCause();
-
-      if (!attemptException.canResume()) {
-        return false;
-      }
-    }
-
-    return super.shouldRetry(context, previousThrowable, previousResponse, nextAttemptSettings);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/TimedAttemptSettings.java b/gax/src/main/java/com/google/api/gax/retrying/TimedAttemptSettings.java
deleted file mode 100644
index 2f9028a2e..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/TimedAttemptSettings.java
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.ApiClock;
-import com.google.auto.value.AutoValue;
-import org.threeten.bp.Duration;
-
-/** Timed attempt execution settings. Defines time-specific properties of a retry attempt. */
-@AutoValue
-public abstract class TimedAttemptSettings {
-
-  /** Returns global (attempt-independent) retry settings. */
-  public abstract RetrySettings getGlobalSettings();
-
-  /**
-   * Returns the calculated retry delay. Note that the actual delay used for retry scheduling may be
-   * different (randomized, based on this value).
-   */
-  public abstract Duration getRetryDelay();
-
-  /** Returns rpc timeout used for this attempt. */
-  public abstract Duration getRpcTimeout();
-
-  /**
-   * Returns randomized attempt delay. By default this value is calculated based on the {@code
-   * retryDelay} value, and is used as the actual attempt execution delay.
-   */
-  public abstract Duration getRandomizedRetryDelay();
-
-  /**
-   * The attempt count. It is a zero-based value (first attempt will have this value set to 0). For
-   * streamed RPCs this will be reset after every successful message.
-   */
-  public abstract int getAttemptCount();
-
-  /**
-   * The overall attempt count. It is a zero-based value (first attempt will have this value set to
-   * 0). This will be the sum of all attempt counts for a streaming RPC and will be equal to {@link
-   * #getAttemptCount()} for unary RPCs.
-   */
-  public abstract int getOverallAttemptCount();
-
-  /**
-   * The start time of the first attempt. Note that this value is dependent on the actual {@link
-   * ApiClock} used during the process.
-   */
-  public abstract long getFirstAttemptStartTimeNanos();
-
-  public abstract Builder toBuilder();
-
-  public static Builder newBuilder() {
-    return new AutoValue_TimedAttemptSettings.Builder().setOverallAttemptCount(0);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    /** Sets global (attempt-independent) retry settings. */
-    public abstract Builder setGlobalSettings(RetrySettings value);
-
-    /**
-     * Sets the calculated retry delay. Note that the actual delay used for retry scheduling may be
-     * different (randomized, based on this value).
-     */
-    public abstract Builder setRetryDelay(Duration value);
-
-    /** Sets rpc timeout used for this attempt. */
-    public abstract Builder setRpcTimeout(Duration value);
-
-    /**
-     * Sets randomized attempt delay. By default this value is calculated based on the {@code
-     * retryDelay} value, and is used as the actual attempt execution delay.
-     */
-    public abstract Builder setRandomizedRetryDelay(Duration value);
-
-    /**
-     * Set the attempt count. It is a zero-based value (first attempt will have this value set to
-     * 0).
-     */
-    public abstract Builder setAttemptCount(int value);
-
-    /**
-     * Set the overall attempt count. It is a zero-based value (first attempt will have this value
-     * set to 0).
-     */
-    public abstract Builder setOverallAttemptCount(int value);
-
-    /**
-     * Set the start time of the first attempt. Note that this value is dependent on the actual
-     * {@link ApiClock} used during the process.
-     */
-    public abstract Builder setFirstAttemptStartTimeNanos(long value);
-
-    public abstract TimedAttemptSettings build();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithm.java
deleted file mode 100644
index 5cae22b20..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithm.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.retrying;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * Same as {@link TimedRetryAlgorithmWithContext}, but without methods that accept a {@link
- * RetryingContext}. Use {@link TimedRetryAlgorithmWithContext} instead of this interface when
- * possible.
- */
-public interface TimedRetryAlgorithm {
-
-  /**
-   * Same as {@link TimedRetryAlgorithmWithContext#createFirstAttempt(RetryingContext)}, but without
-   * a {@link RetryingContext}.
-   *
-   * <p>Use {@link TimedRetryAlgorithmWithContext#createFirstAttempt(RetryingContext)} instead of
-   * this method when possible.
-   */
-  TimedAttemptSettings createFirstAttempt();
-
-  /**
-   * Same as {@link TimedRetryAlgorithmWithContext#createNextAttempt(RetryingContext,
-   * TimedAttemptSettings)}, but without a {@link RetryingContext}.
-   *
-   * <p>Use {@link TimedRetryAlgorithmWithContext#createNextAttempt(RetryingContext,
-   * TimedAttemptSettings)} instead of this method when possible.
-   */
-  TimedAttemptSettings createNextAttempt(TimedAttemptSettings prevSettings);
-
-  /**
-   * Same as {@link TimedRetryAlgorithmWithContext#shouldRetry(RetryingContext,
-   * TimedAttemptSettings)}, but without a {@link RetryingContext}.
-   *
-   * <p>Use {@link TimedRetryAlgorithmWithContext#shouldRetry(RetryingContext,
-   * TimedAttemptSettings)} instead of this method when possible.
-   */
-  boolean shouldRetry(TimedAttemptSettings nextAttemptSettings) throws CancellationException;
-}
diff --git a/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithmWithContext.java b/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithmWithContext.java
deleted file mode 100644
index 72efda7f4..000000000
--- a/gax/src/main/java/com/google/api/gax/retrying/TimedRetryAlgorithmWithContext.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.retrying;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * A timed retry algorithm is responsible for the following operations, based on the previous
- * attempt settings and current time:
- *
- * <ol>
- *   <li>Creating first attempt {@link TimedAttemptSettings}.
- *   <li>Accepting a task for retry so another attempt will be made.
- *   <li>Canceling retrying process so the related {@link java.util.concurrent.Future} will be
- *       canceled.
- *   <li>Creating {@link TimedAttemptSettings} for each subsequent retry attempt.
- * </ol>
- *
- * Implementations of this interface receive a {@link RetryingContext} that can contain specific
- * {@link RetrySettings} and retryable codes that should be used to determine the retry behavior.
- *
- * <p>Implementations of this interface must be be thread-save.
- */
-public interface TimedRetryAlgorithmWithContext extends TimedRetryAlgorithm {
-
-  /**
-   * Creates a first attempt {@link TimedAttemptSettings}.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes
-   * @return first attempt settings
-   */
-  TimedAttemptSettings createFirstAttempt(RetryingContext context);
-
-  /**
-   * Creates a next attempt {@link TimedAttemptSettings}, which defines properties of the next
-   * attempt.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes
-   * @param previousSettings previous attempt settings
-   * @return next attempt settings or {@code null} if the implementing algorithm does not provide
-   *     specific settings for the next attempt
-   */
-  TimedAttemptSettings createNextAttempt(
-      RetryingContext context, TimedAttemptSettings previousSettings);
-
-  /**
-   * Returns {@code true} if another attempt should be made, or {@code false} otherwise.
-   *
-   * @param context a {@link RetryingContext} that can contain custom {@link RetrySettings} and
-   *     retryable codes.
-   * @param nextAttemptSettings attempt settings, which will be used for the next attempt, if
-   *     accepted
-   * @throws CancellationException if the retrying process should be canceled
-   */
-  boolean shouldRetry(RetryingContext context, TimedAttemptSettings nextAttemptSettings);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/AbortedException.java b/gax/src/main/java/com/google/api/gax/rpc/AbortedException.java
deleted file mode 100644
index 4cd2e31b6..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/AbortedException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the operation was aborted, typically due to a concurrency issue like
- * sequencer check failures, transaction aborts, etc.
- */
-public class AbortedException extends ApiException {
-  public AbortedException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public AbortedException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public AbortedException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/AlreadyExistsException.java b/gax/src/main/java/com/google/api/gax/rpc/AlreadyExistsException.java
deleted file mode 100644
index 6ee118898..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/AlreadyExistsException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when some entity that we attempted to create (e.g., file or directory) already
- * exists.
- */
-public class AlreadyExistsException extends ApiException {
-  public AlreadyExistsException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public AlreadyExistsException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public AlreadyExistsException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiCallContext.java b/gax/src/main/java/com/google/api/gax/rpc/ApiCallContext.java
deleted file mode 100644
index 5a34b58e3..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiCallContext.java
+++ /dev/null
@@ -1,269 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.RetryingContext;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.base.Preconditions;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * Context for an API call.
- *
- * <p>An API call can be composed of many RPCs (in case of retries). This class contains settings
- * for both: API calls and RPCs.
- *
- * <p>Implementations need to be immutable because default instances are stored in callable objects.
- *
- * <p>This is transport specific and each transport has an implementation with its own options.
- */
-@InternalExtensionOnly
-public interface ApiCallContext extends RetryingContext {
-
-  /** Returns a new ApiCallContext with the given credentials set. */
-  ApiCallContext withCredentials(Credentials credentials);
-
-  /** Returns a new ApiCallContext with the given channel set. */
-  ApiCallContext withTransportChannel(TransportChannel channel);
-
-  /**
-   * Returns a new ApiCallContext with the given timeout set.
-   *
-   * <p>This sets the maximum amount of time a single unary RPC attempt can take. If retries are
-   * enabled, then this can take much longer, as each RPC attempt will have the same constant
-   * timeout. Unlike a deadline, timeouts are relative durations that are measure from the beginning
-   * of each RPC attempt. Please note that this limits the duration of a server streaming RPC as
-   * well.
-   *
-   * <p>If a method has default {@link com.google.api.gax.retrying.RetrySettings}, the max attempts
-   * and/or total timeout is still respected when scheduling each RPC attempt.
-   */
-  ApiCallContext withTimeout(@Nullable Duration timeout);
-
-  /** Returns the configured per-RPC timeout. */
-  @Nullable
-  Duration getTimeout();
-
-  /**
-   * Returns a new ApiCallContext with the given stream timeout set.
-   *
-   * <p>This timeout only applies to a {@link ServerStreamingCallable}s. It limits the maximum
-   * amount of time that can pass between demand being signaled via {@link
-   * StreamController#request(int)} and actual message delivery to {@link
-   * ResponseObserver#onResponse(Object)}. Or, in the case of automatic flow control, since the last
-   * message was delivered to {@link ResponseObserver#onResponse(Object)}. This is useful to detect
-   * server or connection stalls. When the timeout has been reached, the stream will be closed with
-   * a retryable {@link WatchdogTimeoutException} and a status of {@link StatusCode.Code#ABORTED}.
-   *
-   * <p>A value of {@link Duration#ZERO}, disables the streaming wait timeout and a null value will
-   * use the default in the callable.
-   *
-   * <p>Please note that this timeout is best effort and the maximum resolution is configured in
-   * {@link StubSettings#getStreamWatchdogCheckInterval()}.
-   */
-  ApiCallContext withStreamWaitTimeout(@Nullable Duration streamWaitTimeout);
-
-  /**
-   * Return the stream wait timeout set for this context.
-   *
-   * @see #withStreamWaitTimeout(Duration)
-   */
-  @Nullable
-  Duration getStreamWaitTimeout();
-
-  /**
-   * Returns a new ApiCallContext with the given stream idle timeout set.
-   *
-   * <p>This timeout only applies to a {@link ServerStreamingCallable}s. It limits the maximum
-   * amount of timeout that can pass between a message being received by {@link
-   * ResponseObserver#onResponse(Object)} and demand being signaled via {@link
-   * StreamController#request(int)}. Please note that this timeout is best effort and the maximum
-   * resolution configured in {@link StubSettings#getStreamWatchdogCheckInterval()}. This is useful
-   * to clean up streams that were partially read but never closed. When the timeout has been
-   * reached, the stream will be closed with a nonretryable {@link WatchdogTimeoutException} and a
-   * status of {@link StatusCode.Code#ABORTED}.
-   *
-   * <p>A value of {@link Duration#ZERO}, disables the streaming idle timeout and a null value will
-   * use the default in the callable.
-   *
-   * <p>Please note that this timeout is best effort and the maximum resolution is configured in
-   * {@link StubSettings#getStreamWatchdogCheckInterval()}.
-   */
-  ApiCallContext withStreamIdleTimeout(@Nullable Duration streamIdleTimeout);
-
-  /**
-   * The stream idle timeout set for this context.
-   *
-   * @see #withStreamIdleTimeout(Duration)
-   */
-  @Nullable
-  Duration getStreamIdleTimeout();
-
-  /**
-   * The {@link ApiTracer} that was previously set for this context.
-   *
-   * <p>The {@link ApiTracer} will be used to trace the current operation and to annotate various
-   * events like retries.
-   */
-  @BetaApi("The surface for tracing is not stable yet and may change in the future")
-  @Nonnull
-  ApiTracer getTracer();
-
-  /**
-   * Returns a new {@link ApiCallContext} with the given {@link ApiTracer}.
-   *
-   * <p>The {@link ApiTracer} will be used to trace the current operation and to annotate various
-   * events like retries.
-   *
-   * @param tracer the {@link ApiTracer} to set.
-   */
-  @BetaApi("The surface for tracing is not stable yet and may change in the future")
-  ApiCallContext withTracer(@Nonnull ApiTracer tracer);
-
-  /**
-   * Returns a new ApiCallContext with the given {@link RetrySettings} set.
-   *
-   * <p>This sets the {@link RetrySettings} to use for the RPC. These settings will work in
-   * combination with either the default retryable codes for the RPC, or the retryable codes
-   * supplied through {@link #withRetryableCodes(Set)}. Calling {@link
-   * #withRetrySettings(RetrySettings)} on an RPC that does not include {@link
-   * Code#DEADLINE_EXCEEDED} as one of its retryable codes (or without calling {@link
-   * #withRetryableCodes(Set)} with a set that includes at least {@link Code#DEADLINE_EXCEEDED})
-   * will effectively only set a single timeout that is equal to {@link
-   * RetrySettings#getInitialRpcTimeout()}. If this timeout is exceeded, the RPC will not be retried
-   * and will fail with {@link Code#DEADLINE_EXCEEDED}.
-   *
-   * <p>Example usage:
-   *
-   * <pre>{@code
-   * ApiCallContext context = GrpcCallContext.createDefault()
-   *   .withRetrySettings(RetrySettings.newBuilder()
-   *     .setInitialRetryDelay(Duration.ofMillis(10L))
-   *     .setInitialRpcTimeout(Duration.ofMillis(100L))
-   *     .setMaxAttempts(10)
-   *     .setMaxRetryDelay(Duration.ofSeconds(10L))
-   *     .setMaxRpcTimeout(Duration.ofSeconds(30L))
-   *     .setRetryDelayMultiplier(1.4)
-   *     .setRpcTimeoutMultiplier(1.5)
-   *     .setTotalTimeout(Duration.ofMinutes(10L))
-   *     .build())
-   *   .withRetryableCodes(Sets.newSet(
-   *     StatusCode.Code.UNAVAILABLE,
-   *     StatusCode.Code.DEADLINE_EXCEEDED));
-   * }</pre>
-   *
-   * Setting a logical call timeout for the context can be done similarly with {@link
-   * RetrySettings.Builder#setLogicalTimeout(Duration timeout)}.
-   *
-   * <p>Example usage:
-   *
-   * <pre>{@code
-   * ApiCallContext context = GrpcCallContext.createDefault()
-   *   .withRetrySettings(RetrySettings.newBuilder()
-   *     .setInitialRetryDelay(Duration.ofMillis(10L))
-   *     .setMaxRetryDelay(Duration.ofSeconds(10L))
-   *     .setRetryDelayMultiplier(1.4)
-   *     .setMaxAttempts(10)
-   *     .setLogicalTimeout(Duration.ofSeconds(30L))
-   *     .build());
-   * }</pre>
-   */
-  @BetaApi
-  ApiCallContext withRetrySettings(RetrySettings retrySettings);
-
-  /**
-   * Returns a new ApiCallContext with the given retryable codes set.
-   *
-   * <p>This sets the retryable codes to use for the RPC. These settings will work in combination
-   * with either the default {@link RetrySettings} for the RPC, or the {@link RetrySettings}
-   * supplied through {@link #withRetrySettings(RetrySettings)}.
-   *
-   * <p>Setting a non-empty set of retryable codes for an RPC that is not already retryable by
-   * default, will not have any effect and the RPC will NOT be retried. This option can only be used
-   * to change which codes are considered retryable for an RPC that already has at least one
-   * retryable code in its default settings.
-   */
-  @BetaApi
-  ApiCallContext withRetryableCodes(Set<StatusCode.Code> retryableCodes);
-
-  /** If inputContext is not null, returns it; if it is null, returns the present instance. */
-  ApiCallContext nullToSelf(ApiCallContext inputContext);
-
-  /**
-   * For any values in {@code inputCallContext} that are not null, override the corresponding values
-   * in the present instance.
-   */
-  ApiCallContext merge(ApiCallContext inputCallContext);
-
-  /** Return a new ApiCallContext with the extraHeaders merged into the present instance. */
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  ApiCallContext withExtraHeaders(Map<String, List<String>> extraHeaders);
-
-  /** Return the extra headers set for this context. */
-  @BetaApi("The surface for extra headers is not stable yet and may change in the future.")
-  Map<String, List<String>> getExtraHeaders();
-
-  /**
-   * Return a new ApiCallContext with additional option merged into the present instance. Any
-   * existing value of the key is overwritten.
-   */
-  @BetaApi("The surface for call context options is not stable yet and may change in the future.")
-  <T> ApiCallContext withOption(Key<T> key, T value);
-
-  /** Return the api call context option set for this context. */
-  @SuppressWarnings("unchecked")
-  @BetaApi("The surface for call context options is not stable yet and may change in the future.")
-  <T> T getOption(Key<T> key);
-
-  /** Key for api call context options key-value pair. */
-  final class Key<T> {
-    private final String name;
-
-    private Key(String name) {
-      this.name = name;
-    }
-
-    /** Factory method for creating instances of {@link Key}. */
-    public static <T> Key<T> create(String name) {
-      Preconditions.checkNotNull(name, "Key name cannot be null.");
-      return new Key<>(name);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiClientHeaderProvider.java b/gax/src/main/java/com/google/api/gax/rpc/ApiClientHeaderProvider.java
deleted file mode 100644
index 34d00d0f3..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiClientHeaderProvider.java
+++ /dev/null
@@ -1,223 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.core.GaxProperties;
-import com.google.common.collect.ImmutableMap;
-import java.io.Serializable;
-import java.util.Map;
-
-/**
- * Implementation of HeaderProvider that provides headers describing the API client library making
- * API calls.
- */
-public class ApiClientHeaderProvider implements HeaderProvider, Serializable {
-  private static final long serialVersionUID = -8876627296793342119L;
-  static final String QUOTA_PROJECT_ID_HEADER_KEY = "x-goog-user-project";
-
-  private final Map<String, String> headers;
-
-  protected ApiClientHeaderProvider(Builder builder) {
-    ImmutableMap.Builder<String, String> headersBuilder = ImmutableMap.builder();
-
-    if (builder.getApiClientHeaderKey() != null) {
-      StringBuilder apiClientHeaderValue = new StringBuilder();
-      // Order of tokens matters!!!
-      appendToken(apiClientHeaderValue, builder.getJvmToken());
-      appendToken(apiClientHeaderValue, builder.getClientLibToken());
-      appendToken(apiClientHeaderValue, builder.getGeneratedLibToken());
-      appendToken(apiClientHeaderValue, builder.getGeneratedRuntimeToken());
-      appendToken(apiClientHeaderValue, builder.getTransportToken());
-      if (apiClientHeaderValue.length() > 0) {
-        headersBuilder.put(builder.getApiClientHeaderKey(), apiClientHeaderValue.toString());
-      }
-    }
-
-    if (builder.getResourceHeaderKey() != null && builder.getResourceToken() != null) {
-      headersBuilder.put(builder.getResourceHeaderKey(), builder.getResourceToken());
-    }
-
-    if (builder.getQuotaProjectIdToken() != null) {
-      headersBuilder.put(QUOTA_PROJECT_ID_HEADER_KEY, builder.getQuotaProjectIdToken());
-    }
-
-    this.headers = headersBuilder.build();
-  }
-
-  @Override
-  public Map<String, String> getHeaders() {
-    return headers;
-  }
-
-  protected static void appendToken(StringBuilder sb, String token) {
-    if (token != null) {
-      if (sb.length() > 0) {
-        sb.append(' ');
-      }
-      sb.append(token);
-    }
-  }
-
-  public static Builder newBuilder() {
-    return new Builder();
-  }
-
-  public static String getDefaultApiClientHeaderKey() {
-    return "x-goog-api-client";
-  }
-
-  public static String getDefaultResourceHeaderKey() {
-    return "google-cloud-resource-prefix";
-  }
-
-  public static class Builder {
-    private String apiClientHeaderKey;
-    private String jvmToken;
-    private String clientLibToken;
-    private String generatedLibToken;
-    private String generatedRuntimeToken;
-    private String transportToken;
-    private String quotaProjectIdToken;
-
-    private String resourceHeaderKey;
-    private String resourceToken;
-
-    protected Builder() {
-      // Initialize with default values
-      apiClientHeaderKey = getDefaultApiClientHeaderKey();
-      setJvmToken(GaxProperties.getJavaVersion());
-      clientLibToken = null;
-      generatedLibToken = null;
-      setClientRuntimeToken(GaxProperties.getGaxVersion());
-      transportToken = null;
-      quotaProjectIdToken = null;
-
-      resourceHeaderKey = getDefaultResourceHeaderKey();
-      resourceToken = null;
-    }
-
-    public String getApiClientHeaderKey() {
-      return apiClientHeaderKey;
-    }
-
-    public Builder setApiClientHeaderKey(String apiClientHeaderKey) {
-      this.apiClientHeaderKey = apiClientHeaderKey;
-      return this;
-    }
-
-    public String getJvmToken() {
-      return jvmToken;
-    }
-
-    public Builder setJvmToken(String version) {
-      this.jvmToken = constructToken("gl-java", version);
-      return this;
-    }
-
-    public String getClientLibToken() {
-      return clientLibToken;
-    }
-
-    public Builder setClientLibToken(String name, String version) {
-      this.clientLibToken = constructToken(name, version);
-      return this;
-    }
-
-    public String getGeneratedLibToken() {
-      return generatedLibToken;
-    }
-
-    public Builder setGeneratedLibToken(String name, String version) {
-      this.generatedLibToken = constructToken(name, version);
-      return this;
-    }
-
-    public String getGeneratedRuntimeToken() {
-      return generatedRuntimeToken;
-    }
-
-    public Builder setClientRuntimeToken(String version) {
-      this.generatedRuntimeToken = constructToken("gax", version);
-      return this;
-    }
-
-    public String getTransportToken() {
-      return transportToken;
-    }
-
-    public Builder setTransportToken(String name, String version) {
-      this.transportToken = constructToken(name, version);
-      return this;
-    }
-
-    /** @return the quotaProjectIdToken used for quota and billing purposes. */
-    public String getQuotaProjectIdToken() {
-      return quotaProjectIdToken;
-    }
-
-    /** Sets the project ID used for quota and billing purposes. */
-    public Builder setQuotaProjectIdToken(String quotaProjectIdToken) {
-      this.quotaProjectIdToken = quotaProjectIdToken;
-      return this;
-    }
-
-    public String getResourceHeaderKey() {
-      return resourceHeaderKey;
-    }
-
-    public Builder setResourceHeaderKey(String resourceHeaderKey) {
-      this.resourceHeaderKey = resourceHeaderKey;
-      return this;
-    }
-
-    public String getResourceToken() {
-      return resourceToken;
-    }
-
-    public Builder setResourceToken(String resourceToken) {
-      this.resourceToken = resourceToken;
-      return this;
-    }
-
-    private String constructToken(String name, String version) {
-      if (version == null) {
-        return null;
-      }
-      if (name == null) {
-        throw new IllegalArgumentException("Token name cannot be null");
-      }
-      return name + '/' + version;
-    }
-
-    public ApiClientHeaderProvider build() {
-      return new ApiClientHeaderProvider(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiException.java b/gax/src/main/java/com/google/api/gax/rpc/ApiException.java
deleted file mode 100644
index 3722b894e..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiException.java
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.base.Preconditions;
-import java.util.Map;
-
-/** Represents an exception thrown during an RPC call. */
-public class ApiException extends RuntimeException {
-
-  private static final long serialVersionUID = -4375114339928877996L;
-
-  private final ErrorDetails errorDetails;
-  private final StatusCode statusCode;
-  private final boolean retryable;
-
-  public ApiException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    this(cause, statusCode, retryable, null);
-  }
-
-  public ApiException(String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause);
-    this.statusCode = Preconditions.checkNotNull(statusCode);
-    this.retryable = retryable;
-    this.errorDetails = null;
-  }
-
-  public ApiException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause);
-    this.statusCode = Preconditions.checkNotNull(statusCode);
-    this.retryable = retryable;
-    this.errorDetails = errorDetails;
-  }
-
-  /** Returns whether the failed request can be retried. */
-  public boolean isRetryable() {
-    return retryable;
-  }
-
-  /** Returns the status code of the underlying exception. */
-  public StatusCode getStatusCode() {
-    return statusCode;
-  }
-
-  /**
-   * Returns the reason of the exception. This is a constant value that identifies the proximate
-   * cause of the error. e.g. SERVICE_DISABLED
-   */
-  public String getReason() {
-    if (isErrorInfoEmpty()) {
-      return null;
-    }
-    return errorDetails.getErrorInfo().getReason();
-  }
-
-  /**
-   * Returns the logical grouping to which the "reason" belongs. The error domain is typically the
-   * registered service name of the tool or product that generates the error. e.g. googleapis.com
-   */
-  public String getDomain() {
-    if (isErrorInfoEmpty()) {
-      return null;
-    }
-    return errorDetails.getErrorInfo().getDomain();
-  }
-
-  /** Returns additional structured details about this exception. */
-  public Map<String, String> getMetadata() {
-    if (isErrorInfoEmpty()) {
-      return null;
-    }
-    return errorDetails.getErrorInfo().getMetadataMap();
-  }
-
-  /** Returns all standard error messages that server sends. */
-  public ErrorDetails getErrorDetails() {
-    return errorDetails;
-  }
-
-  private boolean isErrorInfoEmpty() {
-    return errorDetails == null || errorDetails.getErrorInfo() == null;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiExceptionFactory.java b/gax/src/main/java/com/google/api/gax/rpc/ApiExceptionFactory.java
deleted file mode 100644
index 4ca5f41c7..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiExceptionFactory.java
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * A factory class that returns the corresponding type of exception class from the given status
- * code.
- */
-public class ApiExceptionFactory {
-  private ApiExceptionFactory() {}
-
-  public static ApiException createException(
-      Throwable cause, StatusCode statusCode, boolean retryable) {
-    return createException(cause, statusCode, retryable, null);
-  }
-
-  public static ApiException createException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    switch (statusCode.getCode()) {
-      case CANCELLED:
-        return new CancelledException(message, cause, statusCode, retryable);
-      case NOT_FOUND:
-        return new NotFoundException(message, cause, statusCode, retryable);
-      case INVALID_ARGUMENT:
-        return new InvalidArgumentException(message, cause, statusCode, retryable);
-      case DEADLINE_EXCEEDED:
-        return new DeadlineExceededException(message, cause, statusCode, retryable);
-      case ALREADY_EXISTS:
-        return new AlreadyExistsException(message, cause, statusCode, retryable);
-      case PERMISSION_DENIED:
-        return new PermissionDeniedException(message, cause, statusCode, retryable);
-      case RESOURCE_EXHAUSTED:
-        return new ResourceExhaustedException(message, cause, statusCode, retryable);
-      case FAILED_PRECONDITION:
-        return new FailedPreconditionException(message, cause, statusCode, retryable);
-      case ABORTED:
-        return new AbortedException(message, cause, statusCode, retryable);
-      case OUT_OF_RANGE:
-        return new OutOfRangeException(message, cause, statusCode, retryable);
-      case UNIMPLEMENTED:
-        return new UnimplementedException(message, cause, statusCode, retryable);
-      case INTERNAL:
-        return new InternalException(message, cause, statusCode, retryable);
-      case UNAVAILABLE:
-        return new UnavailableException(message, cause, statusCode, retryable);
-      case DATA_LOSS:
-        return new DataLossException(message, cause, statusCode, retryable);
-      case UNAUTHENTICATED:
-        return new UnauthenticatedException(message, cause, statusCode, retryable);
-
-      case UNKNOWN: // Fall through.
-      default:
-        return new UnknownException(message, cause, statusCode, retryable);
-    }
-  }
-
-  public static ApiException createException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    switch (statusCode.getCode()) {
-      case CANCELLED:
-        return new CancelledException(cause, statusCode, retryable, errorDetails);
-      case NOT_FOUND:
-        return new NotFoundException(cause, statusCode, retryable, errorDetails);
-      case INVALID_ARGUMENT:
-        return new InvalidArgumentException(cause, statusCode, retryable, errorDetails);
-      case DEADLINE_EXCEEDED:
-        return new DeadlineExceededException(cause, statusCode, retryable, errorDetails);
-      case ALREADY_EXISTS:
-        return new AlreadyExistsException(cause, statusCode, retryable, errorDetails);
-      case PERMISSION_DENIED:
-        return new PermissionDeniedException(cause, statusCode, retryable, errorDetails);
-      case RESOURCE_EXHAUSTED:
-        return new ResourceExhaustedException(cause, statusCode, retryable, errorDetails);
-      case FAILED_PRECONDITION:
-        return new FailedPreconditionException(cause, statusCode, retryable, errorDetails);
-      case ABORTED:
-        return new AbortedException(cause, statusCode, retryable, errorDetails);
-      case OUT_OF_RANGE:
-        return new OutOfRangeException(cause, statusCode, retryable, errorDetails);
-      case UNIMPLEMENTED:
-        return new UnimplementedException(cause, statusCode, retryable, errorDetails);
-      case INTERNAL:
-        return new InternalException(cause, statusCode, retryable, errorDetails);
-      case UNAVAILABLE:
-        return new UnavailableException(cause, statusCode, retryable, errorDetails);
-      case DATA_LOSS:
-        return new DataLossException(cause, statusCode, retryable, errorDetails);
-      case UNAUTHENTICATED:
-        return new UnauthenticatedException(cause, statusCode, retryable, errorDetails);
-      case UNKNOWN: // Fall through.
-      default:
-        return new UnknownException(cause, statusCode, retryable, errorDetails);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiExceptions.java b/gax/src/main/java/com/google/api/gax/rpc/ApiExceptions.java
deleted file mode 100644
index 1559988e0..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiExceptions.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.UncheckedExecutionException;
-
-/** A utility class for working with {@link ApiException}. */
-public class ApiExceptions {
-  private ApiExceptions() {}
-
-  /**
-   * Invokes {@link ApiFuture#get()} on the given future, and if the call throws an exception (which
-   * will be {@link UncheckedExecutionException}), the exception is processed in the following way:
-   *
-   * <ol>
-   *   <li>If the exception cause is a RuntimeException, the RuntimeException is rethrown. To ease
-   *       debugging, the a {@link AsyncTaskException} is added as a suppressed exception to
-   *       maintain the callsite.
-   *   <li>Otherwise, the UncheckedExecutionException is rethrown.
-   * </ol>
-   */
-  public static <ResponseT> ResponseT callAndTranslateApiException(ApiFuture<ResponseT> future) {
-    try {
-      return Futures.getUnchecked(future);
-    } catch (UncheckedExecutionException exception) {
-      if (exception.getCause() instanceof RuntimeException) {
-        RuntimeException cause = (RuntimeException) exception.getCause();
-        cause.addSuppressed(new AsyncTaskException());
-        throw cause;
-      }
-
-      throw exception;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiResultRetryAlgorithm.java b/gax/src/main/java/com/google/api/gax/rpc/ApiResultRetryAlgorithm.java
deleted file mode 100644
index 688fc32cd..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiResultRetryAlgorithm.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.retrying.BasicResultRetryAlgorithm;
-import com.google.api.gax.retrying.RetryingContext;
-
-/* Package-private for internal use. */
-class ApiResultRetryAlgorithm<ResponseT> extends BasicResultRetryAlgorithm<ResponseT> {
-
-  /** Returns true if previousThrowable is an {@link ApiException} that is retryable. */
-  @Override
-  public boolean shouldRetry(Throwable previousThrowable, ResponseT previousResponse) {
-    return (previousThrowable instanceof ApiException)
-        && ((ApiException) previousThrowable).isRetryable();
-  }
-
-  /**
-   * If {@link RetryingContext#getRetryableCodes()} is not null: Returns true if the status code of
-   * previousThrowable is in the list of retryable code of the {@link RetryingContext}.
-   *
-   * <p>Otherwise it returns the result of {@link #shouldRetry(Throwable, Object)}.
-   */
-  @Override
-  public boolean shouldRetry(
-      RetryingContext context, Throwable previousThrowable, ResponseT previousResponse) {
-    if (context.getRetryableCodes() != null) {
-      // Ignore the isRetryable() value of the throwable if the RetryingContext has a specific list
-      // of codes that should be retried.
-      return (previousThrowable instanceof ApiException)
-          && context
-              .getRetryableCodes()
-              .contains(((ApiException) previousThrowable).getStatusCode().getCode());
-    }
-    return shouldRetry(previousThrowable, previousResponse);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserver.java b/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserver.java
deleted file mode 100644
index 6dd12c311..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserver.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Receives notifications from an observable stream of messages.
- *
- * <p>It is used for sending messages in bidi (bidirectional) or client-streaming calls, or for
- * receiving messages in bidi or server-streaming calls.
- *
- * <p>For outgoing messages, an {@code ApiStreamObserver} is provided by GAX to the application, and
- * the application then provides the messages to send. For incoming messages, the application
- * implements the {@code ApiStreamObserver} and passes it to GAX, which then calls the observer with
- * the messages for the application to receive them.
- *
- * <p>Implementations are expected to be <a
- * href="http://www.ibm.com/developerworks/library/j-jtp09263/">thread-compatible</a>. Separate
- * {@code ApiStreamObserver}s do not need to be synchronized together; incoming and outgoing
- * directions are independent. Since individual {@code ApiStreamObserver}s are not thread-safe, if
- * multiple threads will be writing to a {@code ApiStreamObserver} concurrently, the application
- * must synchronize calls.
- *
- * <p>This interface is a fork of io.grpc.stub.StreamObserver to enable shadowing of Guava, and also
- * to allow for a transport-agnostic interface that doesn't depend on gRPC.
- */
-public interface ApiStreamObserver<V> {
-  /**
-   * Receives a value from the stream.
-   *
-   * <p>Can be called many times but is never called after {@link #onError(Throwable)} or {@link
-   * #onCompleted()} are called.
-   *
-   * <p>Clients may invoke onNext at most once for server streaming calls, but may receive many
-   * onNext callbacks. Servers may invoke onNext at most once for client streaming calls, but may
-   * receive many onNext callbacks.
-   *
-   * <p>If an exception is thrown by an implementation the caller is expected to terminate the
-   * stream by calling {@link #onError(Throwable)} with the caught exception prior to propagating
-   * it.
-   *
-   * @param value the value passed to the stream
-   */
-  void onNext(V value);
-
-  /**
-   * Receives a terminating error from the stream.
-   *
-   * <p>May only be called once and if called, it must be the last method called. In particular if
-   * an exception is thrown by an implementation of {@code onError}, no further calls to any method
-   * are allowed.
-   *
-   * @param t the error occurred on the stream
-   */
-  void onError(Throwable t);
-
-  /**
-   * Receives a notification of successful stream completion.
-   *
-   * <p>May only be called once, and if called it must be the last method called. In particular if
-   * an exception is thrown by an implementation of {@code onCompleted}, no further calls to any
-   * method are allowed.
-   */
-  void onCompleted();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserverAdapter.java b/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserverAdapter.java
deleted file mode 100644
index 7df0e58b8..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ApiStreamObserverAdapter.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Backwards compatibility bridge from the new {@link ResponseObserver} api to the old {@link
- * ApiStreamObserver} api.
- *
- * <p>Package-private for internal use.
- *
- * @param <T> The type of the response.
- * @deprecated Use ResponseObserver directly
- */
-@Deprecated
-class ApiStreamObserverAdapter<T> extends StateCheckingResponseObserver<T> {
-  private final ApiStreamObserver<T> delegate;
-
-  ApiStreamObserverAdapter(ApiStreamObserver<T> delegate) {
-    this.delegate = delegate;
-  }
-
-  @Override
-  protected void onStartImpl(StreamController controller) {
-    // Noop: the old style assumes automatic flow control and doesn't support cancellation.
-  }
-
-  @Override
-  protected void onResponseImpl(T response) {
-    delegate.onNext(response);
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    delegate.onError(t);
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    delegate.onCompleted();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/AsyncTaskException.java b/gax/src/main/java/com/google/api/gax/rpc/AsyncTaskException.java
deleted file mode 100644
index ef3afb1d2..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/AsyncTaskException.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * This exception is used to preserve the caller's stacktrace when invoking an async task in a sync
- * context. It will be added as a suppressed exception when propagating the async exception. This
- * allows callers to catch ApiException thrown in an async operation, while still maintaining the
- * call site.
- */
-public class AsyncTaskException extends RuntimeException {
-  AsyncTaskException() {
-    super("Asynchronous task failed");
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/AttemptCallable.java b/gax/src/main/java/com/google/api/gax/rpc/AttemptCallable.java
deleted file mode 100644
index 6b419f1d4..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/AttemptCallable.java
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.retrying.NonCancellableFuture;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.Callable;
-import org.threeten.bp.Duration;
-
-/**
- * A callable representing an attempt to make an RPC call. This class is used from {@link
- * RetryingCallable}.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> request type
- * @param <ResponseT> response type
- */
-class AttemptCallable<RequestT, ResponseT> implements Callable<ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final RequestT request;
-  private final ApiCallContext originalCallContext;
-
-  private volatile RetryingFuture<ResponseT> externalFuture;
-
-  AttemptCallable(
-      UnaryCallable<RequestT, ResponseT> callable, RequestT request, ApiCallContext callContext) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.request = Preconditions.checkNotNull(request);
-    this.originalCallContext = Preconditions.checkNotNull(callContext);
-  }
-
-  public void setExternalFuture(RetryingFuture<ResponseT> externalFuture) {
-    this.externalFuture = Preconditions.checkNotNull(externalFuture);
-  }
-
-  @Override
-  public ResponseT call() {
-    ApiCallContext callContext = originalCallContext;
-
-    try {
-      // Set the RPC timeout if the caller did not provide their own.
-      Duration rpcTimeout = externalFuture.getAttemptSettings().getRpcTimeout();
-      if (!rpcTimeout.isZero() && callContext.getTimeout() == null) {
-        callContext = callContext.withTimeout(rpcTimeout);
-      }
-
-      externalFuture.setAttemptFuture(new NonCancellableFuture<ResponseT>());
-      if (externalFuture.isDone()) {
-        return null;
-      }
-
-      callContext
-          .getTracer()
-          .attemptStarted(request, externalFuture.getAttemptSettings().getOverallAttemptCount());
-
-      ApiFuture<ResponseT> internalFuture = callable.futureCall(request, callContext);
-      externalFuture.setAttemptFuture(internalFuture);
-    } catch (Throwable e) {
-      externalFuture.setAttemptFuture(ApiFutures.<ResponseT>immediateFailedFuture(e));
-    }
-
-    return null;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/Batch.java b/gax/src/main/java/com/google/api/gax/rpc/Batch.java
deleted file mode 100644
index b23069e89..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/Batch.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.BatchMerger;
-import com.google.api.gax.batching.ElementCounter;
-import com.google.api.gax.batching.RequestBuilder;
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * A Batch contains a collection of requests that are to be batched into a single API call.
- *
- * <p>A Batch contains a single {@link UnaryCallable} object, which will be used to make the API
- * call, and a list of {@link BatchedRequestIssuer} objects, which represent the individual requests
- * in the batch.
- *
- * <p>Additional batches can be merged into an existing batch using the {@link #merge(Batch)}
- * method. Request objects are combined using a {@link RequestBuilder} into a single request.
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi
-public class Batch<RequestT, ResponseT> {
-  private final List<BatchedRequestIssuer<ResponseT>> requestIssuerList;
-
-  private final RequestBuilder<RequestT> requestBuilder;
-  private UnaryCallable<RequestT, ResponseT> callable;
-  private long byteCount;
-
-  public Batch(
-      BatchingDescriptor<RequestT, ResponseT> descriptor,
-      RequestT request,
-      UnaryCallable<RequestT, ResponseT> callable,
-      BatchedFuture<ResponseT> batchedFuture) {
-    this.requestBuilder = descriptor.getRequestBuilder();
-    this.requestIssuerList = new ArrayList<>();
-    this.requestBuilder.appendRequest(request);
-    this.callable = callable;
-    this.requestIssuerList.add(
-        new BatchedRequestIssuer<>(batchedFuture, descriptor.countElements(request)));
-    this.byteCount = descriptor.countBytes(request);
-  }
-
-  public RequestT getRequest() {
-    return requestBuilder.build();
-  }
-
-  public UnaryCallable<RequestT, ResponseT> getCallable() {
-    return callable;
-  }
-
-  public List<BatchedRequestIssuer<ResponseT>> getRequestIssuerList() {
-    return requestIssuerList;
-  }
-
-  public long getByteCount() {
-    return byteCount;
-  }
-
-  /** Merge the given batch into this batch. */
-  public void merge(Batch<RequestT, ResponseT> batch) {
-    requestBuilder.appendRequest(batch.getRequest());
-    requestIssuerList.addAll(batch.requestIssuerList);
-    if (this.callable == null) {
-      this.callable = batch.callable;
-    }
-    this.byteCount += batch.byteCount;
-  }
-
-  static class BatchElementCounter<RequestT, ResponseT>
-      implements ElementCounter<Batch<RequestT, ResponseT>> {
-    private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-
-    BatchElementCounter(BatchingDescriptor<RequestT, ResponseT> batchingDescriptor) {
-      this.batchingDescriptor = batchingDescriptor;
-    }
-
-    @Override
-    public long count(Batch<RequestT, ResponseT> batch) {
-      return batchingDescriptor.countElements(batch.getRequest());
-    }
-  }
-
-  static class BatchByteCounter<RequestT, ResponseT>
-      implements ElementCounter<Batch<RequestT, ResponseT>> {
-    @Override
-    public long count(Batch<RequestT, ResponseT> batch) {
-      return batch.getByteCount();
-    }
-  }
-
-  static class BatchMergerImpl<RequestT, ResponseT>
-      implements BatchMerger<Batch<RequestT, ResponseT>> {
-    @Override
-    public void merge(Batch<RequestT, ResponseT> batch, Batch<RequestT, ResponseT> newBatch) {
-      batch.merge(newBatch);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchExecutor.java b/gax/src/main/java/com/google/api/gax/rpc/BatchExecutor.java
deleted file mode 100644
index c8d6405ca..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchExecutor.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.ThresholdBatchReceiver;
-import com.google.common.base.Preconditions;
-import java.util.List;
-
-/**
- * A ThresholdBatchReceiver which uses a provided {@link BatchingDescriptor} to merge the items from
- * the Batch into a single request, invoke the callable from the Batch to issue the request, split
- * the batch response into the components matching each incoming request, and finally send the
- * result back to the listener for each request.
- *
- * <p>BatchExecutor methods validateBatch and processBatch use the thread-safe guarantee of
- * BatchingDescriptor to achieve thread safety.
- *
- * <p>Package-private for internal use.
- */
-class BatchExecutor<RequestT, ResponseT>
-    implements ThresholdBatchReceiver<Batch<RequestT, ResponseT>> {
-
-  private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-  private final PartitionKey partitionKey;
-
-  public BatchExecutor(
-      BatchingDescriptor<RequestT, ResponseT> batchingDescriptor, PartitionKey partitionKey) {
-    this.batchingDescriptor = Preconditions.checkNotNull(batchingDescriptor);
-    this.partitionKey = Preconditions.checkNotNull(partitionKey);
-  }
-
-  @Override
-  public void validateBatch(Batch<RequestT, ResponseT> item) {
-    PartitionKey itemPartitionKey = batchingDescriptor.getBatchPartitionKey(item.getRequest());
-    if (!itemPartitionKey.equals(partitionKey)) {
-      String requestClassName = item.getRequest().getClass().getSimpleName();
-      throw new IllegalArgumentException(
-          String.format(
-              "For type %s, invalid partition key: %s, should be: %s",
-              requestClassName, itemPartitionKey, partitionKey));
-    }
-  }
-
-  @Override
-  public ApiFuture<ResponseT> processBatch(Batch<RequestT, ResponseT> batch) {
-    UnaryCallable<RequestT, ResponseT> callable = batch.getCallable();
-    RequestT request = batch.getRequest();
-    final List<BatchedRequestIssuer<ResponseT>> requestIssuerList = batch.getRequestIssuerList();
-    ApiFuture<ResponseT> future = callable.futureCall(request);
-    ApiFutures.addCallback(
-        future,
-        new ApiFutureCallback<ResponseT>() {
-          @Override
-          public void onSuccess(ResponseT result) {
-            batchingDescriptor.splitResponse(result, requestIssuerList);
-            for (BatchedRequestIssuer<ResponseT> requestIssuer : requestIssuerList) {
-              requestIssuer.sendResult();
-            }
-          }
-
-          @Override
-          public void onFailure(Throwable t) {
-            batchingDescriptor.splitException(t, requestIssuerList);
-            for (BatchedRequestIssuer<ResponseT> requestIssuer : requestIssuerList) {
-              requestIssuer.sendResult();
-            }
-          }
-        },
-        directExecutor());
-    return future;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchedFuture.java b/gax/src/main/java/com/google/api/gax/rpc/BatchedFuture.java
deleted file mode 100644
index 6f91230f8..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchedFuture.java
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.InternalApi;
-
-/**
- * An ApiFuture to be used with batching.
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi
-public class BatchedFuture<ResponseT> extends AbstractApiFuture<ResponseT> {
-
-  /** Get a new instance. */
-  public static <T> BatchedFuture<T> create() {
-    return new BatchedFuture<>();
-  }
-
-  @Override
-  public boolean set(ResponseT value) {
-    return super.set(value);
-  }
-
-  @Override
-  public boolean setException(Throwable throwable) {
-    return super.setException(throwable);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchedRequestIssuer.java b/gax/src/main/java/com/google/api/gax/rpc/BatchedRequestIssuer.java
deleted file mode 100644
index 599fa5183..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchedRequestIssuer.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.base.Preconditions;
-
-/**
- * BatchedRequestIssuer receives a response or an exception and waits to set the given batchedFuture
- * until sendResult() is called.
- *
- * <p>This class is designed to be used by generated code.
- */
-public final class BatchedRequestIssuer<ResponseT> {
-  private final BatchedFuture<ResponseT> batchedFuture;
-  private final long messageCount;
-  private ResponseT responseToSend;
-  private boolean hasResponse;
-  private Throwable throwableToSend;
-
-  public BatchedRequestIssuer(BatchedFuture<ResponseT> batchedFuture, long messageCount) {
-    this.batchedFuture = batchedFuture;
-    this.messageCount = messageCount;
-    this.responseToSend = null;
-    this.throwableToSend = null;
-  }
-
-  public long getMessageCount() {
-    return messageCount;
-  }
-
-  /**
-   * Set the response to set on the batched future. If this is called, setException cannot be
-   * called.
-   */
-  public void setResponse(ResponseT response) {
-    Preconditions.checkState(throwableToSend == null, "Cannot set both exception and response");
-    hasResponse = true;
-    responseToSend = response;
-  }
-
-  /**
-   * Set the exception to set on the batched future. If this is called, setResponse cannot be
-   * called.
-   */
-  public void setException(Throwable throwable) {
-    Preconditions.checkState(!hasResponse, "Cannot set both exception and response");
-    throwableToSend = throwable;
-  }
-
-  /** Sends back the result that was stored by either setResponse or setException */
-  public void sendResult() {
-    if (hasResponse) {
-      batchedFuture.set(responseToSend);
-    } else if (throwableToSend != null) {
-      batchedFuture.setException(throwableToSend);
-    } else {
-      throw new IllegalStateException(
-          "Neither response nor exception were set in BatchedRequestIssuer");
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatcherFactory.java b/gax/src/main/java/com/google/api/gax/rpc/BatcherFactory.java
deleted file mode 100644
index 8ac809399..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatcherFactory.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.BatchingFlowController;
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.BatchingThreshold;
-import com.google.api.gax.batching.ElementCounter;
-import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.batching.NumericThreshold;
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.ThresholdBatcher;
-import com.google.api.gax.rpc.Batch.BatchByteCounter;
-import com.google.api.gax.rpc.Batch.BatchElementCounter;
-import com.google.api.gax.rpc.Batch.BatchMergerImpl;
-import com.google.common.collect.ImmutableList;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ScheduledExecutorService;
-
-/**
- * A Factory class which, for each unique partitionKey, creates a trio including a ThresholdBatcher,
- * BatchExecutor, and ThresholdBatchingForwarder. The ThresholdBatchingForwarder pulls items from
- * the ThresholdBatcher and forwards them to the BatchExecutor for processing.
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi
-public final class BatcherFactory<RequestT, ResponseT> {
-  private final Map<PartitionKey, ThresholdBatcher<Batch<RequestT, ResponseT>>> batchers =
-      new ConcurrentHashMap<>();
-  private final ScheduledExecutorService executor;
-  private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-  private final FlowController flowController;
-  private final BatchingSettings batchingSettings;
-  private final Object lock = new Object();
-
-  public BatcherFactory(
-      BatchingDescriptor<RequestT, ResponseT> batchingDescriptor,
-      BatchingSettings batchingSettings,
-      ScheduledExecutorService executor,
-      FlowController flowController) {
-    this.batchingDescriptor = batchingDescriptor;
-    this.batchingSettings = batchingSettings;
-    this.executor = executor;
-    this.flowController = flowController;
-  }
-
-  /**
-   * Provides the ThresholdBatcher corresponding to the given partitionKey, or constructs one if it
-   * doesn't exist yet. The implementation is thread-safe.
-   */
-  public ThresholdBatcher<Batch<RequestT, ResponseT>> getPushingBatcher(PartitionKey partitionKey) {
-    ThresholdBatcher<Batch<RequestT, ResponseT>> batcher = batchers.get(partitionKey);
-    if (batcher == null) {
-      synchronized (lock) {
-        batcher = batchers.get(partitionKey);
-        if (batcher == null) {
-          batcher = createBatcher(partitionKey);
-          batchers.put(partitionKey, batcher);
-        }
-      }
-    }
-    return batcher;
-  }
-
-  /**
-   * Returns the BatchingSettings object that is associated with this factory.
-   *
-   * <p>This is public only for technical reasons, for advanced usage.
-   */
-  @InternalApi
-  public BatchingSettings getBatchingSettings() {
-    return batchingSettings;
-  }
-
-  private ThresholdBatcher<Batch<RequestT, ResponseT>> createBatcher(PartitionKey partitionKey) {
-    BatchExecutor<RequestT, ResponseT> processor =
-        new BatchExecutor<>(batchingDescriptor, partitionKey);
-    BatchingFlowController<Batch<RequestT, ResponseT>> batchingFlowController =
-        new BatchingFlowController<>(
-            flowController,
-            new BatchElementCounter<>(batchingDescriptor),
-            new BatchByteCounter<RequestT, ResponseT>());
-    return ThresholdBatcher.<Batch<RequestT, ResponseT>>newBuilder()
-        .setThresholds(getThresholds(batchingSettings))
-        .setExecutor(executor)
-        .setMaxDelay(batchingSettings.getDelayThreshold())
-        .setReceiver(processor)
-        .setFlowController(batchingFlowController)
-        .setBatchMerger(new BatchMergerImpl<RequestT, ResponseT>())
-        .build();
-  }
-
-  private ImmutableList<BatchingThreshold<Batch<RequestT, ResponseT>>> getThresholds(
-      BatchingSettings batchingSettings) {
-    ImmutableList.Builder<BatchingThreshold<Batch<RequestT, ResponseT>>> listBuilder =
-        ImmutableList.builder();
-
-    if (batchingSettings.getElementCountThreshold() != null) {
-      ElementCounter<Batch<RequestT, ResponseT>> elementCounter =
-          new BatchElementCounter<>(batchingDescriptor);
-
-      BatchingThreshold<Batch<RequestT, ResponseT>> countThreshold =
-          new NumericThreshold<>(batchingSettings.getElementCountThreshold(), elementCounter);
-      listBuilder.add(countThreshold);
-    }
-
-    if (batchingSettings.getRequestByteThreshold() != null) {
-      ElementCounter<Batch<RequestT, ResponseT>> requestByteCounter =
-          new BatchByteCounter<RequestT, ResponseT>();
-
-      BatchingThreshold<Batch<RequestT, ResponseT>> byteThreshold =
-          new NumericThreshold<>(batchingSettings.getRequestByteThreshold(), requestByteCounter);
-      listBuilder.add(byteThreshold);
-    }
-
-    return listBuilder.build();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchingCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/BatchingCallSettings.java
deleted file mode 100644
index 922f48640..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchingCallSettings.java
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import java.util.Set;
-
-/**
- * A settings class to configure a {@link UnaryCallable} for calls to an API method that supports
- * batching. The settings are provided using an instance of {@link BatchingSettings}.
- */
-@InternalExtensionOnly
-public final class BatchingCallSettings<RequestT, ResponseT>
-    extends UnaryCallSettings<RequestT, ResponseT> {
-  private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-  private final BatchingSettings batchingSettings;
-  private final FlowController flowController;
-
-  public BatchingDescriptor<RequestT, ResponseT> getBatchingDescriptor() {
-    return batchingDescriptor;
-  }
-
-  public BatchingSettings getBatchingSettings() {
-    return batchingSettings;
-  }
-
-  public FlowController getFlowController() {
-    return flowController;
-  }
-
-  private BatchingCallSettings(Builder<RequestT, ResponseT> builder) {
-    super(builder);
-    this.batchingDescriptor = builder.batchingDescriptor;
-    this.batchingSettings = Preconditions.checkNotNull(builder.batchingSettings);
-    FlowController flowControllerToUse = builder.flowController;
-    if (flowControllerToUse == null) {
-      flowControllerToUse = new FlowController(batchingSettings.getFlowControlSettings());
-    }
-    this.flowController = flowControllerToUse;
-  }
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder(
-      BatchingDescriptor<RequestT, ResponseT> batchingDescriptor) {
-    return new Builder<>(batchingDescriptor);
-  }
-
-  @Override
-  public final Builder<RequestT, ResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("retryableCodes", getRetryableCodes())
-        .add("retrySettings", getRetrySettings())
-        .add("batchingSettings", batchingSettings)
-        .toString();
-  }
-
-  public static class Builder<RequestT, ResponseT>
-      extends UnaryCallSettings.Builder<RequestT, ResponseT> {
-
-    private BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-    private BatchingSettings batchingSettings;
-    private FlowController flowController;
-
-    public Builder(BatchingDescriptor<RequestT, ResponseT> batchingDescriptor) {
-      this.batchingDescriptor = batchingDescriptor;
-    }
-
-    public Builder(BatchingCallSettings<RequestT, ResponseT> settings) {
-      super(settings);
-      this.batchingDescriptor = settings.batchingDescriptor;
-      this.batchingSettings = settings.batchingSettings;
-      // TODO decide if a copy should be made
-      this.flowController = settings.flowController;
-    }
-
-    public BatchingDescriptor<RequestT, ResponseT> getBatchingDescriptor() {
-      return batchingDescriptor;
-    }
-
-    public Builder<RequestT, ResponseT> setBatchingSettings(BatchingSettings batchingSettings) {
-      this.batchingSettings = batchingSettings;
-      return this;
-    }
-
-    public BatchingSettings getBatchingSettings() {
-      return batchingSettings;
-    }
-
-    public Builder<RequestT, ResponseT> setFlowController(FlowController flowController) {
-      this.flowController = flowController;
-      return this;
-    }
-
-    public FlowController getFlowController() {
-      return flowController;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT> setRetryableCodes(Set<StatusCode.Code> retryableCodes) {
-      super.setRetryableCodes(retryableCodes);
-      return this;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT> setRetryableCodes(StatusCode.Code... codes) {
-      super.setRetryableCodes(codes);
-      return this;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT> setRetrySettings(RetrySettings retrySettings) {
-      super.setRetrySettings(retrySettings);
-      return this;
-    }
-
-    @Override
-    public BatchingCallSettings<RequestT, ResponseT> build() {
-      return new BatchingCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/BatchingCallable.java
deleted file mode 100644
index 2d6a1f37a..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchingCallable.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.api.gax.batching.FlowController.FlowControlRuntimeException;
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.ThresholdBatcher;
-import com.google.common.base.Preconditions;
-
-/**
- * A {@link UnaryCallable} which will batch requests based on the given BatchingDescriptor and
- * BatcherFactory. The BatcherFactory provides a distinct Batcher for each partition as specified by
- * the BatchingDescriptor. An example of a batching partition would be a pubsub topic.
- *
- * <p>This is public only for technical reasons, for advanced usage.
- */
-@InternalApi("For use by transport-specific implementations")
-public class BatchingCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-  private final BatcherFactory<RequestT, ResponseT> batcherFactory;
-
-  public BatchingCallable(
-      UnaryCallable<RequestT, ResponseT> callable,
-      BatchingDescriptor<RequestT, ResponseT> batchingDescriptor,
-      BatcherFactory<RequestT, ResponseT> batcherFactory) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.batchingDescriptor = Preconditions.checkNotNull(batchingDescriptor);
-    this.batcherFactory = Preconditions.checkNotNull(batcherFactory);
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-    if (batcherFactory.getBatchingSettings().getIsEnabled()) {
-      BatchedFuture<ResponseT> result = BatchedFuture.<ResponseT>create();
-      UnaryCallable<RequestT, ResponseT> unaryCallable = callable.withDefaultCallContext(context);
-      Batch<RequestT, ResponseT> batchableMessage =
-          new Batch<RequestT, ResponseT>(batchingDescriptor, request, unaryCallable, result);
-      PartitionKey partitionKey = batchingDescriptor.getBatchPartitionKey(request);
-      ThresholdBatcher<Batch<RequestT, ResponseT>> batcher =
-          batcherFactory.getPushingBatcher(partitionKey);
-      try {
-        batcher.add(batchableMessage);
-        return result;
-      } catch (FlowControlException e) {
-        throw FlowControlRuntimeException.fromFlowControlException(e);
-      }
-    } else {
-      return callable.futureCall(request, context);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BatchingDescriptor.java b/gax/src/main/java/com/google/api/gax/rpc/BatchingDescriptor.java
deleted file mode 100644
index ce4cf737c..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BatchingDescriptor.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.RequestBuilder;
-import java.util.Collection;
-
-/**
- * Interface which represents an object that transforms request/response data for the purposes of
- * batching.
- *
- * <p>Implementations of BatchingDescriptor must guarantee that all methods are stateless and thread
- * safe.
- *
- * <p>This class is designed to be used by generated code.
- */
-public interface BatchingDescriptor<RequestT, ResponseT> {
-
-  /** Returns the value of the partition key for the given request. */
-  PartitionKey getBatchPartitionKey(RequestT request);
-
-  /** Get the Builder object for the request type RequestT. */
-  RequestBuilder<RequestT> getRequestBuilder();
-
-  /**
-   * Splits the result from a batched call into an individual setResponse call on each
-   * RequestIssuer.
-   */
-  void splitResponse(
-      ResponseT batchResponse, Collection<? extends BatchedRequestIssuer<ResponseT>> batch);
-
-  /**
-   * Splits the exception that resulted from a batched call into an individual setException call on
-   * each RequestIssuer.
-   */
-  void splitException(
-      Throwable throwable, Collection<? extends BatchedRequestIssuer<ResponseT>> batch);
-
-  /** Returns the number of elements contained in this request. */
-  long countElements(RequestT request);
-
-  /** Returns the size in bytes of this request. */
-  long countBytes(RequestT request);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BidiStream.java b/gax/src/main/java/com/google/api/gax/rpc/BidiStream.java
deleted file mode 100644
index a47468567..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BidiStream.java
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-
-/**
- * A wrapper around a bidirectional stream.
- *
- * <p>This class asynchronously pulls responses from upstream via {@link
- * StreamController#request(int)} and exposes them via its Iterator. The implementation is back
- * pressure aware and uses a constant buffer of 1 item.
- *
- * <p>Please note that the stream can only be consumed once and must either be fully consumed or be
- * canceled.
- *
- * <p>This class can also be used to send requests to the server using {@link #send(Object)}.
- *
- * <p>Neither this class nor the iterator it returns is thread-safe.
- *
- * <p>In the example below, we iterate through responses from the server and echo back the items we
- * see:
- *
- * <pre>{@code
- * BidiStream<Item> stream = ...;
- *
- * for (Item item : stream) {
- *   System.out.println(item.id());
- *
- *   stream.send(item.id());
- *
- *   // Allow for early termination
- *   if (item.id().equals("needle")) {
- *     // Cancelling the stream will cause `hasNext()` to return false on the next iteration,
- *     // naturally breaking the loop.
- *     stream.cancel();
- *   }
- * }
- * }</pre>
- *
- * @param <RequestT> The type of each request.
- * @param <ResponseT> The type of each response.
- */
-public class BidiStream<RequestT, ResponseT> extends ServerStream<ResponseT>
-    implements ClientStream<RequestT> {
-
-  private ClientStream<RequestT> clientStream;
-
-  @InternalApi("For use by BidiStreamingCallable only.")
-  BidiStream() {}
-
-  @InternalApi("For use by BidiStreamingCallable only.")
-  void setClientStream(ClientStream<RequestT> clientStream) {
-    this.clientStream = clientStream;
-  }
-
-  /** Send {@code req} to the server. */
-  @Override
-  public void send(RequestT req) {
-    clientStream.send(req);
-  }
-
-  /**
-   * Reports whether a message can be sent without requiring excessive buffering internally.
-   *
-   * <p>This method only provides a hint. It is still correct for the user to call {@link
-   * #send(Object)} even when this method returns {@code false}.
-   */
-  @Override
-  public boolean isSendReady() {
-    return clientStream.isSendReady();
-  }
-
-  /**
-   * Closes the sending side of the stream. Once called, no further calls to {@link #send(Object)},
-   * {@link #closeSend()}, or {@link #closeSendWithError(Throwable)} are allowed.
-   *
-   * <p>Calling this method does not affect the receiving side, the iterator will continue to yield
-   * responses from the server.
-   */
-  @Override
-  public void closeSend() {
-    clientStream.closeSend();
-  }
-
-  /**
-   * Closes the sending side of the stream with error. The error is propagated to the server. Once
-   * called, no further calls to {@link #send(Object)}, {@link #closeSend()}, or {@link
-   * #closeSendWithError(Throwable)} are allowed.
-   *
-   * <p>Calling this method does not affect the receiving side, the iterator will continue to yield
-   * responses from the server.
-   */
-  @Override
-  public void closeSendWithError(Throwable t) {
-    clientStream.closeSendWithError(t);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BidiStreamObserver.java b/gax/src/main/java/com/google/api/gax/rpc/BidiStreamObserver.java
deleted file mode 100644
index 427a68068..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BidiStreamObserver.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-public interface BidiStreamObserver<RequestT, ResponseT>
-    extends ResponseObserver<ResponseT>, ClientStreamReadyObserver<RequestT> {}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/BidiStreamingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/BidiStreamingCallable.java
deleted file mode 100644
index c97367588..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/BidiStreamingCallable.java
+++ /dev/null
@@ -1,258 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * A BidiStreamingCallable is an immutable object which is capable of making RPC calls to
- * bidirectional streaming API methods. Not all transports support streaming.
- *
- * <p>It is considered advanced usage for a user to create a BidiStreamingCallable themselves. This
- * class is intended to be created by a generated client class, and configured by instances of
- * StreamingCallSettings.Builder which are exposed through the client settings class.
- */
-public abstract class BidiStreamingCallable<RequestT, ResponseT> {
-
-  protected BidiStreamingCallable() {}
-
-  /**
-   * The "base" method from which other forms of {@code call}s are derived. Most users will not need
-   * to call this method directly.
-   *
-   * <p>However, it is {@code public}, since library authors might want to call this method in
-   * adaptor classes.
-   */
-  public abstract ClientStream<RequestT> internalCall(
-      ResponseObserver<ResponseT> responseObserver,
-      ClientStreamReadyObserver<RequestT> onReady,
-      ApiCallContext context);
-
-  /**
-   * Listens to server responses and send requests when the network is free. Example usage:
-   *
-   * <pre>{@code
-   * final Iterator<Integer> sourceDataIterator = intCollection.iterator();
-   * BidiStreamObserver<Integer, String> bidiStreamObserver = new BidiStreamObserver<Integer, String>() {
-   *   public void onStart(StreamController controller) {
-   *     // no-op
-   *   }
-   *
-   *   public void onResponse(String response) {
-   *     System.out.println(response);
-   *   }
-   *
-   *   public void onComplete() {
-   *     System.out.println("done!");
-   *   }
-   *
-   *   public void onError(Throwable t) {
-   *     System.out.println("error: " + t);
-   *   }
-   *
-   *   public void onReady(ClientStream<Integer> stream) {
-   *     while (sourceDataIterator.hasNext()) {
-   *       if (stream.isReady()) {
-   *         stream.send(sourceDataIterator.next());
-   *       } else {
-   *         // It's OK we haven't consumed the whole iterator;
-   *         // onReady will be called again when the network becomes free.
-   *         return;
-   *       }
-   *     }
-   *     // We ran out of things to send.
-   *     stream.close();
-   *   }
-   * };
-   *
-   * bidiStreamingCallable.call(bidiStreamObserver);
-   * }</pre>
-   */
-  public void call(final BidiStreamObserver<RequestT, ResponseT> bidiObserver) {
-    call(bidiObserver, null);
-  }
-
-  /** Listens to server responses and send requests when the network is free. */
-  public void call(
-      final BidiStreamObserver<RequestT, ResponseT> bidiObserver, ApiCallContext context) {
-    internalCall(
-        bidiObserver,
-        new ClientStreamReadyObserver<RequestT>() {
-          @Override
-          public void onReady(ClientStream<RequestT> stream) {
-            bidiObserver.onReady(stream);
-          }
-        },
-        context);
-  }
-
-  /**
-   * Send requests and iterate over server responses.
-   *
-   * <p>This returns a live stream that must either be fully consumed or cancelled. Example usage:
-   *
-   * <pre>{@code
-   * BidiStream<String, String> stream = bidiStreamingCallable.call()
-   * for (String s : stream) {
-   *   if ("needle".equals(s)) {
-   *     // Cancelling the stream will cause `hasNext()` to return false on the next iteration,
-   *     // naturally breaking the loop.
-   *     stream.cancel();
-   *   }
-   *   stream.send(s);
-   * }
-   * }</pre>
-   */
-  public BidiStream<RequestT, ResponseT> call() {
-    return call((ApiCallContext) null);
-  }
-
-  /**
-   * Send requests and iterate over server responses.
-   *
-   * <p>This returns a live stream that must either be fully consumed or cancelled.
-   */
-  public BidiStream<RequestT, ResponseT> call(ApiCallContext context) {
-    BidiStream<RequestT, ResponseT> stream = new BidiStream<>();
-    ClientStream<RequestT> clientStream = splitCall(stream.observer(), context);
-    stream.setClientStream(clientStream);
-    return stream;
-  }
-
-  /**
-   * Send requests to the server and listens to responses.
-   *
-   * <p>Example usage:
-   *
-   * <pre>{@code
-   * ResponseObserver<String> responseObserver = new ResponseObserver<String>() {
-   *   public void onStart(StreamController controller) {
-   *     // no-op
-   *   }
-   *
-   *  public void onResponse(String response) {
-   *    System.out.println(response);
-   *  }
-   *
-   *  public void onComplete() {
-   *    System.out.println("done!");
-   *  }
-   *
-   *  public void onError(Throwable t) {
-   *    System.out.println("error: " + t);
-   *  }
-   * };
-   *
-   * ClientStream<Integer> clientStream = bidiStreamingCallable.splitCall(responseObserver);
-   * clientStream.send(42);
-   * clientStream.send(43);
-   * clientStream.close();
-   * }</pre>
-   */
-  public ClientStream<RequestT> splitCall(ResponseObserver<ResponseT> responseObserver) {
-    return splitCall(responseObserver, null);
-  }
-
-  /** Send requests to the server and listens to responses. */
-  public ClientStream<RequestT> splitCall(
-      ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-    return internalCall(
-        responseObserver,
-        new ClientStreamReadyObserver<RequestT>() {
-          @Override
-          public void onReady(ClientStream<RequestT> stream) {
-            // no op
-          }
-        },
-        context);
-  }
-
-  /**
-   * Conduct a bidirectional streaming call with the given {@link ApiCallContext}.
-   *
-   * @param responseObserver {@link ApiStreamObserver} to observe the streaming responses
-   * @param context {@link ApiCallContext} to provide context information for the RPC call.
-   * @return {@link ApiStreamObserver} which is used for making streaming requests.
-   * @deprecated Please use {@link #splitCall(ResponseObserver, ApiCallContext)} instead.
-   */
-  @Deprecated
-  public ApiStreamObserver<RequestT> bidiStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context) {
-    final ClientStream<RequestT> stream =
-        splitCall(new ApiStreamObserverAdapter<>(responseObserver), context);
-    return new ApiStreamObserver<RequestT>() {
-      @Override
-      public void onNext(RequestT request) {
-        stream.send(request);
-      }
-
-      @Override
-      public void onError(Throwable t) {
-        stream.closeSendWithError(t);
-      }
-
-      @Override
-      public void onCompleted() {
-        stream.closeSend();
-      }
-    };
-  }
-
-  /**
-   * Conduct a bidirectional streaming call
-   *
-   * @param responseObserver {@link ApiStreamObserver} to observe the streaming responses
-   * @return {@link ApiStreamObserver} which is used for making streaming requests.
-   * @deprecated Please use {@link #splitCall(ResponseObserver)} instead.
-   */
-  @Deprecated
-  public ApiStreamObserver<RequestT> bidiStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver) {
-    return bidiStreamingCall(responseObserver, null);
-  }
-
-  /**
-   * Returns a new {@code BidiStreamingCallable} with an {@link ApiCallContext} that is used as a
-   * default when none is supplied in individual calls.
-   *
-   * @param defaultCallContext the default {@link ApiCallContext}.
-   */
-  public BidiStreamingCallable<RequestT, ResponseT> withDefaultCallContext(
-      final ApiCallContext defaultCallContext) {
-    return new BidiStreamingCallable<RequestT, ResponseT>() {
-      @Override
-      public ClientStream<RequestT> internalCall(
-          ResponseObserver<ResponseT> responseObserver,
-          ClientStreamReadyObserver<RequestT> onReady,
-          ApiCallContext thisCallContext) {
-        return BidiStreamingCallable.this.internalCall(
-            responseObserver, onReady, defaultCallContext.merge(thisCallContext));
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/Callables.java b/gax/src/main/java/com/google/api/gax/rpc/Callables.java
deleted file mode 100644
index 413a11649..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/Callables.java
+++ /dev/null
@@ -1,235 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.longrunning.OperationResponsePollAlgorithm;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.ExponentialRetryAlgorithm;
-import com.google.api.gax.retrying.RetryAlgorithm;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.ScheduledRetryingExecutor;
-import com.google.api.gax.retrying.StreamingRetryAlgorithm;
-import java.util.Collection;
-
-/**
- * Class with utility methods to create callable objects using provided settings.
- *
- * <p>The callable objects wrap a given direct callable with features like retry and exception
- * translation.
- */
-@BetaApi
-public class Callables {
-
-  private Callables() {}
-
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> retrying(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      UnaryCallSettings<?, ?> callSettings,
-      ClientContext clientContext) {
-
-    UnaryCallSettings<?, ?> settings = callSettings;
-
-    if (areRetriesDisabled(settings.getRetryableCodes(), settings.getRetrySettings())) {
-      // When retries are disabled, the total timeout can be treated as the rpc timeout.
-      settings =
-          settings
-              .toBuilder()
-              .setSimpleTimeoutNoRetries(settings.getRetrySettings().getTotalTimeout())
-              .build();
-    }
-
-    RetryAlgorithm<ResponseT> retryAlgorithm =
-        new RetryAlgorithm<>(
-            new ApiResultRetryAlgorithm<ResponseT>(),
-            new ExponentialRetryAlgorithm(settings.getRetrySettings(), clientContext.getClock()));
-    ScheduledRetryingExecutor<ResponseT> retryingExecutor =
-        new ScheduledRetryingExecutor<>(retryAlgorithm, clientContext.getExecutor());
-    return new RetryingCallable<>(
-        clientContext.getDefaultCallContext(), innerCallable, retryingExecutor);
-  }
-
-  public static <RequestT, ResponseT> ServerStreamingCallable<RequestT, ResponseT> retrying(
-      ServerStreamingCallable<RequestT, ResponseT> innerCallable,
-      ServerStreamingCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-
-    ServerStreamingCallSettings<RequestT, ResponseT> settings = callSettings;
-    if (areRetriesDisabled(settings.getRetryableCodes(), settings.getRetrySettings())) {
-      // When retries are disabled, the total timeout can be treated as the rpc timeout.
-      settings =
-          settings
-              .toBuilder()
-              .setSimpleTimeoutNoRetries(settings.getRetrySettings().getTotalTimeout())
-              .build();
-    }
-
-    StreamingRetryAlgorithm<Void> retryAlgorithm =
-        new StreamingRetryAlgorithm<>(
-            new ApiResultRetryAlgorithm<Void>(),
-            new ExponentialRetryAlgorithm(settings.getRetrySettings(), clientContext.getClock()));
-
-    ScheduledRetryingExecutor<Void> retryingExecutor =
-        new ScheduledRetryingExecutor<>(retryAlgorithm, clientContext.getExecutor());
-
-    return new RetryingServerStreamingCallable<>(
-        innerCallable, retryingExecutor, settings.getResumptionStrategy());
-  }
-
-  public static <RequestT, ResponseT> ServerStreamingCallable<RequestT, ResponseT> watched(
-      ServerStreamingCallable<RequestT, ResponseT> callable,
-      ServerStreamingCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-
-    callable = new WatchdogServerStreamingCallable<>(callable, clientContext.getStreamWatchdog());
-
-    callable =
-        callable.withDefaultCallContext(
-            clientContext
-                .getDefaultCallContext()
-                .withStreamIdleTimeout(callSettings.getIdleTimeout()));
-
-    return callable;
-  }
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param innerCallable the callable to issue calls
-   * @param batchingCallSettings {@link BatchingSettings} to configure the batching related settings
-   *     with.
-   * @param context {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> batching(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext context) {
-    return batchingImpl(innerCallable, batchingCallSettings, context).unaryCallable;
-  }
-
-  /** This only exists to give tests access to batcherFactory for flushing purposes. */
-  static class BatchingCreateResult<RequestT, ResponseT> {
-    private final BatcherFactory<RequestT, ResponseT> batcherFactory;
-    private final UnaryCallable<RequestT, ResponseT> unaryCallable;
-
-    private BatchingCreateResult(
-        BatcherFactory<RequestT, ResponseT> batcherFactory,
-        UnaryCallable<RequestT, ResponseT> unaryCallable) {
-      this.batcherFactory = batcherFactory;
-      this.unaryCallable = unaryCallable;
-    }
-
-    public BatcherFactory<RequestT, ResponseT> getBatcherFactory() {
-      return batcherFactory;
-    }
-
-    public UnaryCallable<RequestT, ResponseT> getUnaryCallable() {
-      return unaryCallable;
-    }
-  }
-
-  static <RequestT, ResponseT> BatchingCreateResult<RequestT, ResponseT> batchingImpl(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext) {
-    BatcherFactory<RequestT, ResponseT> batcherFactory =
-        new BatcherFactory<>(
-            batchingCallSettings.getBatchingDescriptor(),
-            batchingCallSettings.getBatchingSettings(),
-            clientContext.getExecutor(),
-            batchingCallSettings.getFlowController());
-    UnaryCallable<RequestT, ResponseT> callable =
-        new BatchingCallable<>(
-            innerCallable, batchingCallSettings.getBatchingDescriptor(), batcherFactory);
-    return new BatchingCreateResult<>(batcherFactory, callable);
-  }
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param innerCallable the callable to issue calls
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> paged(
-          UnaryCallable<RequestT, ResponseT> innerCallable,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings) {
-    return new PagedCallable<>(innerCallable, pagedCallSettings.getPagedListResponseFactory());
-  }
-
-  /**
-   * Creates a callable object that represents a long-running operation. Designed for use by
-   * generated code.
-   *
-   * @param initialCallable the callable that initiates the operation
-   * @param operationCallSettings {@link OperationCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @param longRunningClient {@link LongRunningClient} to use to poll for updates on the Operation.
-   * @return {@link OperationCallable} callable object.
-   */
-  public static <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> longRunningOperation(
-          UnaryCallable<RequestT, OperationSnapshot> initialCallable,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          LongRunningClient longRunningClient) {
-    return longRunningOperationImpl(
-        initialCallable, operationCallSettings, clientContext, longRunningClient);
-  }
-
-  static <RequestT, ResponseT, MetadataT>
-      OperationCallableImpl<RequestT, ResponseT, MetadataT> longRunningOperationImpl(
-          UnaryCallable<RequestT, OperationSnapshot> initialCallable,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          LongRunningClient longRunningClient) {
-    RetryAlgorithm<OperationSnapshot> pollingAlgorithm =
-        new RetryAlgorithm<>(
-            new OperationResponsePollAlgorithm(), operationCallSettings.getPollingAlgorithm());
-    ScheduledRetryingExecutor<OperationSnapshot> scheduler =
-        new ScheduledRetryingExecutor<>(pollingAlgorithm, clientContext.getExecutor());
-
-    return new OperationCallableImpl<>(
-        initialCallable, scheduler, longRunningClient, operationCallSettings);
-  }
-
-  private static boolean areRetriesDisabled(
-      Collection<StatusCode.Code> retryableCodes, RetrySettings retrySettings) {
-    return retrySettings.getMaxAttempts() == 1
-        || retryableCodes.isEmpty()
-        || (retrySettings.getMaxAttempts() == 0 && retrySettings.getTotalTimeout().isZero());
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/CancelledException.java b/gax/src/main/java/com/google/api/gax/rpc/CancelledException.java
deleted file mode 100644
index 7bc15f04c..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/CancelledException.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** The exception thrown when the operation was cancelled (typically by the caller). */
-public class CancelledException extends ApiException {
-  public CancelledException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public CancelledException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public CancelledException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/CheckingAttemptCallable.java b/gax/src/main/java/com/google/api/gax/rpc/CheckingAttemptCallable.java
deleted file mode 100644
index 17670a5e7..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/CheckingAttemptCallable.java
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.retrying.NonCancellableFuture;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.Callable;
-import org.threeten.bp.Duration;
-
-/**
- * A callable representing an attempt to check the status of something by issuing a call to a
- * UnaryCallable. This class is used from {@link RecheckingCallable}.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> request type
- * @param <ResponseT> response type
- */
-class CheckingAttemptCallable<RequestT, ResponseT> implements Callable<ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final ApiCallContext originalCallContext;
-
-  private volatile RetryingFuture<ResponseT> externalFuture;
-
-  CheckingAttemptCallable(UnaryCallable<RequestT, ResponseT> callable, ApiCallContext callContext) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.originalCallContext = Preconditions.checkNotNull(callContext);
-  }
-
-  public void setExternalFuture(RetryingFuture<ResponseT> externalFuture) {
-    this.externalFuture = Preconditions.checkNotNull(externalFuture);
-  }
-
-  @Override
-  public ResponseT call() {
-    ApiCallContext callContext = originalCallContext;
-
-    try {
-      Duration rpcTimeout = externalFuture.getAttemptSettings().getRpcTimeout();
-      if (!rpcTimeout.isZero()) {
-        callContext = callContext.withTimeout(rpcTimeout);
-      }
-
-      externalFuture.setAttemptFuture(new NonCancellableFuture<ResponseT>());
-      if (externalFuture.isDone()) {
-        return null;
-      }
-
-      callContext
-          .getTracer()
-          .attemptStarted(externalFuture.getAttemptSettings().getOverallAttemptCount());
-
-      // NOTE: The callable here is an OperationCheckingCallable, which will compose its own
-      // request using a resolved operation name and ignore anything that we pass here for the
-      // request.
-      ApiFuture<ResponseT> internalFuture = callable.futureCall(null, callContext);
-      externalFuture.setAttemptFuture(internalFuture);
-    } catch (Throwable e) {
-      externalFuture.setAttemptFuture(ApiFutures.<ResponseT>immediateFailedFuture(e));
-    }
-
-    return null;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ClientContext.java b/gax/src/main/java/com/google/api/gax/rpc/ClientContext.java
deleted file mode 100644
index 45a54e549..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ClientContext.java
+++ /dev/null
@@ -1,330 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.BetaApi;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.ExecutorAsBackgroundResource;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.rpc.internal.QuotaProjectIdHidingCredentials;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.api.gax.tracing.ApiTracerFactory;
-import com.google.api.gax.tracing.BaseApiTracerFactory;
-import com.google.auth.Credentials;
-import com.google.auto.value.AutoValue;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Sets;
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * Encapsulates client state, including executor, credentials, and transport channel.
- *
- * <p>Unlike {@link ClientSettings} which allows users to configure the client, {@code
- * ClientContext} is intended to be used in generated code. Most users will not need to use it.
- */
-@AutoValue
-public abstract class ClientContext {
-  private static final String QUOTA_PROJECT_ID_HEADER_KEY = "x-goog-user-project";
-
-  /**
-   * The objects that need to be closed in order to clean up the resources created in the process of
-   * creating this ClientContext. This will include the closeables from the transport context.
-   */
-  public abstract List<BackgroundResource> getBackgroundResources();
-
-  /**
-   * Gets the executor to use for running scheduled API call logic (such as retries and long-running
-   * operations).
-   */
-  public abstract ScheduledExecutorService getExecutor();
-
-  @Nullable
-  public abstract Credentials getCredentials();
-
-  @Nullable
-  public abstract TransportChannel getTransportChannel();
-
-  public abstract Map<String, String> getHeaders();
-
-  protected abstract Map<String, String> getInternalHeaders();
-
-  public abstract ApiClock getClock();
-
-  public abstract ApiCallContext getDefaultCallContext();
-
-  @Nullable
-  public abstract Watchdog getStreamWatchdog();
-
-  @Nonnull
-  public abstract Duration getStreamWatchdogCheckInterval();
-
-  @Nullable
-  public abstract String getEndpoint();
-
-  @Nullable
-  public abstract String getQuotaProjectId();
-
-  /** Gets the {@link ApiTracerFactory} that will be used to generate traces for operations. */
-  @BetaApi("The surface for tracing is not stable yet and may change in the future.")
-  @Nonnull
-  public abstract ApiTracerFactory getTracerFactory();
-
-  public static Builder newBuilder() {
-    return new AutoValue_ClientContext.Builder()
-        .setBackgroundResources(Collections.<BackgroundResource>emptyList())
-        .setExecutor(Executors.newScheduledThreadPool(0))
-        .setHeaders(Collections.<String, String>emptyMap())
-        .setInternalHeaders(Collections.<String, String>emptyMap())
-        .setClock(NanoClock.getDefaultClock())
-        .setStreamWatchdog(null)
-        .setStreamWatchdogCheckInterval(Duration.ZERO)
-        .setTracerFactory(BaseApiTracerFactory.getInstance())
-        .setQuotaProjectId(null);
-  }
-
-  public abstract Builder toBuilder();
-
-  /**
-   * Instantiates the executor, credentials, and transport context based on the given client
-   * settings.
-   */
-  public static ClientContext create(ClientSettings settings) throws IOException {
-    return create(settings.getStubSettings());
-  }
-
-  /** Returns the endpoint that should be used. See https://google.aip.dev/auth/4114. */
-  static String getEndpoint(
-      String endpoint,
-      String mtlsEndpoint,
-      boolean switchToMtlsEndpointAllowed,
-      MtlsProvider mtlsProvider)
-      throws IOException {
-    if (switchToMtlsEndpointAllowed) {
-      switch (mtlsProvider.getMtlsEndpointUsagePolicy()) {
-        case ALWAYS:
-          return mtlsEndpoint;
-        case NEVER:
-          return endpoint;
-        default:
-          if (mtlsProvider.useMtlsClientCertificate() && mtlsProvider.getKeyStore() != null) {
-            return mtlsEndpoint;
-          }
-          return endpoint;
-      }
-    }
-    return endpoint;
-  }
-
-  /**
-   * Instantiates the executor, credentials, and transport context based on the given client
-   * settings.
-   */
-  public static ClientContext create(StubSettings settings) throws IOException {
-    ApiClock clock = settings.getClock();
-
-    ExecutorProvider backgroundExecutorProvider = settings.getBackgroundExecutorProvider();
-    final ScheduledExecutorService backgroundExecutor = backgroundExecutorProvider.getExecutor();
-
-    Credentials credentials = settings.getCredentialsProvider().getCredentials();
-
-    if (settings.getQuotaProjectId() != null) {
-      // If the quotaProjectId is set, wrap original credentials with correct quotaProjectId as
-      // QuotaProjectIdHidingCredentials.
-      // Ensure that a custom set quota project id takes priority over one detected by credentials.
-      // Avoid the backend receiving possibly conflict values of quotaProjectId
-      credentials = new QuotaProjectIdHidingCredentials(credentials);
-    }
-
-    TransportChannelProvider transportChannelProvider = settings.getTransportChannelProvider();
-    // After needsExecutor and StubSettings#setExecutorProvider are deprecated, transport channel
-    // executor can only be set from TransportChannelProvider#withExecutor directly, and a provider
-    // will have a default executor if it needs one.
-    if (transportChannelProvider.needsExecutor() && settings.getExecutorProvider() != null) {
-      transportChannelProvider = transportChannelProvider.withExecutor(backgroundExecutor);
-    }
-    Map<String, String> headers = getHeadersFromSettings(settings);
-    if (transportChannelProvider.needsHeaders()) {
-      transportChannelProvider = transportChannelProvider.withHeaders(headers);
-    }
-    if (transportChannelProvider.needsCredentials() && credentials != null) {
-      transportChannelProvider = transportChannelProvider.withCredentials(credentials);
-    }
-    String endpoint =
-        getEndpoint(
-            settings.getEndpoint(),
-            settings.getMtlsEndpoint(),
-            settings.getSwitchToMtlsEndpointAllowed(),
-            new MtlsProvider());
-    if (transportChannelProvider.needsEndpoint()) {
-      transportChannelProvider = transportChannelProvider.withEndpoint(endpoint);
-    }
-    TransportChannel transportChannel = transportChannelProvider.getTransportChannel();
-
-    ApiCallContext defaultCallContext =
-        transportChannel.getEmptyCallContext().withTransportChannel(transportChannel);
-    if (credentials != null) {
-      defaultCallContext = defaultCallContext.withCredentials(credentials);
-    }
-
-    WatchdogProvider watchdogProvider = settings.getStreamWatchdogProvider();
-    @Nullable Watchdog watchdog = null;
-
-    if (watchdogProvider != null) {
-      if (watchdogProvider.needsCheckInterval()) {
-        watchdogProvider =
-            watchdogProvider.withCheckInterval(settings.getStreamWatchdogCheckInterval());
-      }
-      if (watchdogProvider.needsClock()) {
-        watchdogProvider = watchdogProvider.withClock(clock);
-      }
-      if (watchdogProvider.needsExecutor()) {
-        watchdogProvider = watchdogProvider.withExecutor(backgroundExecutor);
-      }
-      watchdog = watchdogProvider.getWatchdog();
-    }
-
-    ImmutableList.Builder<BackgroundResource> backgroundResources = ImmutableList.builder();
-
-    if (transportChannelProvider.shouldAutoClose()) {
-      backgroundResources.add(transportChannel);
-    }
-    if (backgroundExecutorProvider.shouldAutoClose()) {
-      backgroundResources.add(new ExecutorAsBackgroundResource(backgroundExecutor));
-    }
-    if (watchdogProvider != null && watchdogProvider.shouldAutoClose()) {
-      backgroundResources.add(watchdog);
-    }
-
-    return newBuilder()
-        .setBackgroundResources(backgroundResources.build())
-        .setExecutor(backgroundExecutor)
-        .setCredentials(credentials)
-        .setTransportChannel(transportChannel)
-        .setHeaders(ImmutableMap.copyOf(settings.getHeaderProvider().getHeaders()))
-        .setInternalHeaders(ImmutableMap.copyOf(settings.getInternalHeaderProvider().getHeaders()))
-        .setClock(clock)
-        .setDefaultCallContext(defaultCallContext)
-        .setEndpoint(settings.getEndpoint())
-        .setQuotaProjectId(settings.getQuotaProjectId())
-        .setStreamWatchdog(watchdog)
-        .setStreamWatchdogCheckInterval(settings.getStreamWatchdogCheckInterval())
-        .setTracerFactory(settings.getTracerFactory())
-        .build();
-  }
-
-  /**
-   * Getting a header map from HeaderProvider and InternalHeaderProvider from settings with Quota
-   * Project Id.
-   */
-  private static Map<String, String> getHeadersFromSettings(StubSettings settings) {
-    // Resolve conflicts when merging headers from multiple sources
-    Map<String, String> userHeaders = settings.getHeaderProvider().getHeaders();
-    Map<String, String> internalHeaders = settings.getInternalHeaderProvider().getHeaders();
-    Map<String, String> conflictResolution = new HashMap<>();
-
-    Set<String> conflicts = Sets.intersection(userHeaders.keySet(), internalHeaders.keySet());
-    for (String key : conflicts) {
-      if ("user-agent".equals(key)) {
-        conflictResolution.put(key, userHeaders.get(key) + " " + internalHeaders.get(key));
-        continue;
-      }
-      // Backwards compat: quota project id can conflict if its overriden in settings
-      if (QUOTA_PROJECT_ID_HEADER_KEY.equals(key) && settings.getQuotaProjectId() != null) {
-        continue;
-      }
-      throw new IllegalArgumentException("Header provider can't override the header: " + key);
-    }
-    if (settings.getQuotaProjectId() != null) {
-      conflictResolution.put(QUOTA_PROJECT_ID_HEADER_KEY, settings.getQuotaProjectId());
-    }
-
-    Map<String, String> effectiveHeaders = new HashMap<>();
-    effectiveHeaders.putAll(internalHeaders);
-    effectiveHeaders.putAll(userHeaders);
-    effectiveHeaders.putAll(conflictResolution);
-
-    return ImmutableMap.copyOf(effectiveHeaders);
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-
-    public abstract Builder setBackgroundResources(List<BackgroundResource> backgroundResources);
-
-    /**
-     * Sets the executor to use for running scheduled API call logic (such as retries and
-     * long-running operations).
-     */
-    public abstract Builder setExecutor(ScheduledExecutorService value);
-
-    public abstract Builder setCredentials(Credentials value);
-
-    public abstract Builder setTransportChannel(TransportChannel transportChannel);
-
-    public abstract Builder setHeaders(Map<String, String> headers);
-
-    protected abstract Builder setInternalHeaders(Map<String, String> headers);
-
-    public abstract Builder setClock(ApiClock clock);
-
-    public abstract Builder setDefaultCallContext(ApiCallContext defaultCallContext);
-
-    public abstract Builder setEndpoint(String endpoint);
-
-    public abstract Builder setQuotaProjectId(String QuotaProjectId);
-
-    public abstract Builder setStreamWatchdog(Watchdog watchdog);
-
-    public abstract Builder setStreamWatchdogCheckInterval(Duration duration);
-
-    /**
-     * Set the {@link ApiTracerFactory} that will be used to generate traces for operations.
-     *
-     * @param tracerFactory an instance {@link ApiTracerFactory}.
-     */
-    @BetaApi("The surface for tracing is not stable yet and may change in the future.")
-    public abstract Builder setTracerFactory(ApiTracerFactory tracerFactory);
-
-    public abstract ClientContext build();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ClientSettings.java b/gax/src/main/java/com/google/api/gax/rpc/ClientSettings.java
deleted file mode 100644
index a1097a410..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ClientSettings.java
+++ /dev/null
@@ -1,350 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.core.CredentialsProvider;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.common.base.MoreObjects;
-import java.io.IOException;
-import java.util.concurrent.Executor;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * A base settings class to configure a client class.
- *
- * <p>This base class includes settings that are applicable to all services, which includes things
- * like settings for creating an executor, credentials, transport-specific settings, and identifiers
- * for http headers.
- *
- * <p>If no ExecutorProvider is set, then InstantiatingExecutorProvider will be used, which creates
- * a default executor.
- */
-public abstract class ClientSettings<SettingsT extends ClientSettings<SettingsT>> {
-
-  private final StubSettings stubSettings;
-
-  /** Constructs an instance of ClientSettings. */
-  protected ClientSettings(Builder builder) throws IOException {
-    this.stubSettings = builder.stubSettings.build();
-  }
-
-  public final StubSettings getStubSettings() {
-    return stubSettings;
-  }
-
-  /** @deprecated Please use {@link #getBackgroundExecutorProvider()} */
-  @Deprecated
-  public final ExecutorProvider getExecutorProvider() {
-    return stubSettings.getExecutorProvider();
-  }
-
-  public final ExecutorProvider getBackgroundExecutorProvider() {
-    return stubSettings.getBackgroundExecutorProvider();
-  }
-
-  public final TransportChannelProvider getTransportChannelProvider() {
-    return stubSettings.getTransportChannelProvider();
-  }
-
-  public final CredentialsProvider getCredentialsProvider() {
-    return stubSettings.getCredentialsProvider();
-  }
-
-  public final HeaderProvider getHeaderProvider() {
-    return stubSettings.getHeaderProvider();
-  }
-
-  protected final HeaderProvider getInternalHeaderProvider() {
-    return stubSettings.getInternalHeaderProvider();
-  }
-
-  public final ApiClock getClock() {
-    return stubSettings.getClock();
-  }
-
-  public final String getEndpoint() {
-    return stubSettings.getEndpoint();
-  }
-
-  public final String getQuotaProjectId() {
-    return stubSettings.getQuotaProjectId();
-  }
-
-  @Nullable
-  public final WatchdogProvider getWatchdogProvider() {
-    return stubSettings.getStreamWatchdogProvider();
-  }
-
-  @Nonnull
-  public final Duration getWatchdogCheckInterval() {
-    return stubSettings.getStreamWatchdogCheckInterval();
-  }
-
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("executorProvider", getExecutorProvider())
-        .add("backgroundExecutorProvider", getBackgroundExecutorProvider())
-        .add("transportChannelProvider", getTransportChannelProvider())
-        .add("credentialsProvider", getCredentialsProvider())
-        .add("headerProvider", getHeaderProvider())
-        .add("internalHeaderProvider", getInternalHeaderProvider())
-        .add("clock", getClock())
-        .add("endpoint", getEndpoint())
-        .add("quotaProjectId", getQuotaProjectId())
-        .add("watchdogProvider", getWatchdogProvider())
-        .add("watchdogCheckInterval", getWatchdogCheckInterval())
-        .toString();
-  }
-
-  public abstract <B extends Builder<SettingsT, B>> B toBuilder();
-
-  public abstract static class Builder<
-      SettingsT extends ClientSettings<SettingsT>, B extends Builder<SettingsT, B>> {
-
-    private StubSettings.Builder stubSettings;
-
-    /** Create a builder from a ClientSettings object. */
-    protected Builder(ClientSettings settings) {
-      this.stubSettings = settings.stubSettings.toBuilder();
-    }
-
-    /** Create a builder from a StubSettings object. */
-    protected Builder(StubSettings.Builder stubSettings) {
-      this.stubSettings = stubSettings;
-    }
-
-    protected Builder() {
-      this((StubSettings.Builder) null);
-    }
-
-    @SuppressWarnings("unchecked")
-    protected B self() {
-      return (B) this;
-    }
-
-    protected StubSettings.Builder getStubSettings() {
-      return stubSettings;
-    }
-
-    /**
-     * Sets the ExecutorProvider to use for getting the executor to use for running asynchronous API
-     * call logic (such as retries and long-running operations), and also to pass to the transport
-     * settings if an executor is needed for the transport and it doesn't have its own executor
-     * provider.
-     *
-     * @deprecated Please use {@link #setBackgroundExecutorProvider(ExecutorProvider)} for setting
-     *     executor to use for running scheduled API call logic. To set executor for {@link
-     *     TransportChannelProvider}, please use {@link
-     *     TransportChannelProvider#withExecutor(Executor)} instead.
-     */
-    @Deprecated
-    public B setExecutorProvider(ExecutorProvider executorProvider) {
-      stubSettings.setExecutorProvider(executorProvider);
-      stubSettings.setBackgroundExecutorProvider(executorProvider);
-      return self();
-    }
-
-    /**
-     * Sets the ExecutorProvider to use for getting the executor to use for running scheduled API
-     * call logic (such as retries and long-running operations). This will not set the executor in
-     * {@link TransportChannelProvider}. To set executor for {@link TransportChannelProvider},
-     * please use {@link TransportChannelProvider#withExecutor(Executor)}.
-     */
-    public B setBackgroundExecutorProvider(ExecutorProvider executorProvider) {
-      stubSettings.setBackgroundExecutorProvider(executorProvider);
-      return self();
-    }
-
-    /** Sets the CredentialsProvider to use for getting the credentials to make calls with. */
-    public B setCredentialsProvider(CredentialsProvider credentialsProvider) {
-      stubSettings.setCredentialsProvider(credentialsProvider);
-      return self();
-    }
-
-    /**
-     * Sets the HeaderProvider for getting custom static headers for http requests. The header
-     * provider will be called during client construction only once. The headers returned by the
-     * provider will be cached and supplied as is for each request issued by the constructed client.
-     * Some reserved headers can be overridden (e.g. Content-Type) or merged with the default value
-     * (e.g. User-Agent) by the underlying transport layer.
-     */
-    public B setHeaderProvider(HeaderProvider headerProvider) {
-      stubSettings.setHeaderProvider(headerProvider);
-      return self();
-    }
-
-    /**
-     * Sets the HeaderProvider for getting internal (library-defined) static headers for http
-     * requests. The header provider will be called during client construction only once. The
-     * headers returned by the provider will be cached and supplied as is for each request issued by
-     * the constructed client. Some reserved headers can be overridden (e.g. Content-Type) or merged
-     * with the default value (e.g. User-Agent) by the underlying transport layer.
-     */
-    protected B setInternalHeaderProvider(HeaderProvider internalHeaderProvider) {
-      stubSettings.setInternalHeaderProvider(internalHeaderProvider);
-      return self();
-    }
-
-    /**
-     * Sets the TransportProvider to use for getting the transport-specific context to make calls
-     * with.
-     */
-    public B setTransportChannelProvider(TransportChannelProvider transportChannelProvider) {
-      stubSettings.setTransportChannelProvider(transportChannelProvider);
-      return self();
-    }
-
-    /**
-     * Sets the clock to use for retry logic.
-     *
-     * <p>This will default to a system clock if it is not set.
-     */
-    public B setClock(ApiClock clock) {
-      stubSettings.setClock(clock);
-      return self();
-    }
-
-    public B setEndpoint(String endpoint) {
-      stubSettings.setEndpoint(endpoint);
-      return self();
-    }
-
-    public B setQuotaProjectId(String quotaProjectId) {
-      stubSettings.setQuotaProjectId(quotaProjectId);
-      return self();
-    }
-
-    public B setWatchdogProvider(@Nullable WatchdogProvider watchdogProvider) {
-      stubSettings.setStreamWatchdogProvider(watchdogProvider);
-      return self();
-    }
-
-    public B setWatchdogCheckInterval(@Nullable Duration checkInterval) {
-      stubSettings.setStreamWatchdogCheckInterval(checkInterval);
-      return self();
-    }
-
-    /**
-     * Gets the ExecutorProvider that was previously set on this Builder. This ExecutorProvider is
-     * to use for running asynchronous API call logic (such as retries and long-running operations),
-     * and also to pass to the transport settings if an executor is needed for the transport and it
-     * doesn't have its own executor provider.
-     *
-     * @deprecated Please use {@link #getBackgroundExecutorProvider()} for getting the executor
-     *     provider that's used for running scheduled API call logic.
-     */
-    @Deprecated
-    public ExecutorProvider getExecutorProvider() {
-      return stubSettings.getExecutorProvider();
-    }
-
-    /**
-     * Gets the ExecutorProvider that was previously set on this Builder. This ExecutorProvider is
-     * to use for running asynchronous API call logic (such as retries and long-running operations).
-     * This ExecutorProvider is not used to set the executor in {@link TransportChannelProvider}.
-     */
-    public ExecutorProvider getBackgroundExecutorProvider() {
-      return stubSettings.getBackgroundExecutorProvider();
-    }
-
-    /** Gets the TransportProvider that was previously set on this Builder. */
-    public TransportChannelProvider getTransportChannelProvider() {
-      return stubSettings.getTransportChannelProvider();
-    }
-
-    /** Gets the CredentialsProvider that was previously set on this Builder. */
-    public CredentialsProvider getCredentialsProvider() {
-      return stubSettings.getCredentialsProvider();
-    }
-
-    /** Gets the custom HeaderProvider that was previously set on this Builder. */
-    public HeaderProvider getHeaderProvider() {
-      return stubSettings.getHeaderProvider();
-    }
-
-    /** Gets the internal HeaderProvider that was previously set on this Builder. */
-    protected HeaderProvider getInternalHeaderProvider() {
-      return stubSettings.getInternalHeaderProvider();
-    }
-
-    /** Gets the ApiClock that was previously set on this Builder. */
-    public ApiClock getClock() {
-      return stubSettings.getClock();
-    }
-
-    public String getEndpoint() {
-      return stubSettings.getEndpoint();
-    }
-
-    /** Gets the QuotaProjectId that was previously set on this Builder. */
-    public String getQuotaProjectId() {
-      return stubSettings.getQuotaProjectId();
-    }
-
-    @Nullable
-    public WatchdogProvider getWatchdogProvider() {
-      return stubSettings.getStreamWatchdogProvider();
-    }
-
-    @Nullable
-    public Duration getWatchdogCheckInterval() {
-      return stubSettings.getStreamWatchdogCheckInterval();
-    }
-
-    /** Applies the given settings updater function to the given method settings builders. */
-    protected static void applyToAllUnaryMethods(
-        Iterable<UnaryCallSettings.Builder<?, ?>> methodSettingsBuilders,
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
-      StubSettings.Builder.applyToAllUnaryMethods(methodSettingsBuilders, settingsUpdater);
-    }
-
-    public abstract SettingsT build() throws IOException;
-
-    public String toString() {
-      return MoreObjects.toStringHelper(this)
-          .add("executorProvider", getExecutorProvider())
-          .add("backgroundExecutorProvider", getBackgroundExecutorProvider())
-          .add("transportChannelProvider", getTransportChannelProvider())
-          .add("credentialsProvider", getCredentialsProvider())
-          .add("headerProvider", getHeaderProvider())
-          .add("internalHeaderProvider", getInternalHeaderProvider())
-          .add("clock", getClock())
-          .add("endpoint", getEndpoint())
-          .add("quotaProjectId", getQuotaProjectId())
-          .add("watchdogProvider", getWatchdogProvider())
-          .add("watchdogCheckInterval", getWatchdogCheckInterval())
-          .toString();
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ClientStream.java b/gax/src/main/java/com/google/api/gax/rpc/ClientStream.java
deleted file mode 100644
index 0a451b68d..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ClientStream.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * A wrapper used to send requests to the server.
- *
- * <p>After sending requests, users must either call {@link #closeSend()} or {@link
- * #closeSendWithError(Throwable)} on the stream. The error, if any, will be propagated to the
- * server.
- *
- * <p>Example usage:
- *
- * <pre>{@code
- * ClientStream<String> stream = ...;
- * List<String> lines = getLinesFromFile();
- * for (String line : lines) {
- *   stream.send(line);
- * }
- * stream.closeSend();
- * }</pre>
- *
- * @param <RequestT> The type of each request.
- */
-public interface ClientStream<RequestT> {
-  /** Sends a request to the server. It is an error to call this if the stream is already closed. */
-  void send(RequestT request);
-
-  /**
-   * Closes the stream with an error. If called, this must be the last call on this {@code
-   * ClientStream}.
-   */
-  void closeSendWithError(Throwable t);
-
-  /**
-   * Closes the stream. If called, this must be the last call on this {@code ClientStream}.
-   *
-   * <p>Note that if {@code close()} itself throws, a further call to {@code closeSendWithError} is
-   * not allowed.
-   */
-  void closeSend();
-
-  /**
-   * Reports whether a new request can be sent without excessive buffering.
-   *
-   * <p>This is only an optimization hint to the user. It is correct, if suboptimal, to call {@code
-   * send} if {@code isSendReady} returns false.
-   */
-  boolean isSendReady();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ClientStreamReadyObserver.java b/gax/src/main/java/com/google/api/gax/rpc/ClientStreamReadyObserver.java
deleted file mode 100644
index 034752451..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ClientStreamReadyObserver.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** A callback used to report that the {@link ClientStream} is ready to send more messages. */
-public interface ClientStreamReadyObserver<V> {
-  void onReady(ClientStream<V> stream);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ClientStreamingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/ClientStreamingCallable.java
deleted file mode 100644
index 13ef1c645..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ClientStreamingCallable.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * A ClientStreamingCallable is an immutable object which is capable of making RPC calls to client
- * streaming API methods. Not all transports support streaming.
- *
- * <p>It is considered advanced usage for a user to create a ClientStreamingCallable themselves.
- * This class is intended to be created by a generated client class, and configured by instances of
- * StreamingCallSettings.Builder which are exposed through the client settings class.
- */
-public abstract class ClientStreamingCallable<RequestT, ResponseT> {
-
-  protected ClientStreamingCallable() {}
-
-  /**
-   * Conduct a client streaming call with the given {@link ApiCallContext}
-   *
-   * @param responseObserver {@link ApiStreamObserver} to receive the non-streaming response.
-   * @param context {@link ApiCallContext} to provide context information for the RPC call.
-   * @return {@link ApiStreamObserver} which is used for making streaming requests.
-   */
-  public abstract ApiStreamObserver<RequestT> clientStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context);
-
-  /**
-   * Conduct a client streaming call
-   *
-   * @param responseObserver {@link ApiStreamObserver} to receive the non-streaming response.
-   * @return {@link ApiStreamObserver} which is used for making streaming requests.
-   */
-  public ApiStreamObserver<RequestT> clientStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver) {
-    return clientStreamingCall(responseObserver, null);
-  }
-
-  /**
-   * Returns a new {@code ClientStreamingCallable} with an {@link ApiCallContext} that is used as a
-   * default when none is supplied in individual calls.
-   *
-   * @param defaultCallContext the default {@link ApiCallContext}.
-   */
-  public ClientStreamingCallable<RequestT, ResponseT> withDefaultCallContext(
-      final ApiCallContext defaultCallContext) {
-    return new ClientStreamingCallable<RequestT, ResponseT>() {
-      @Override
-      public ApiStreamObserver<RequestT> clientStreamingCall(
-          ApiStreamObserver<ResponseT> responseObserver, ApiCallContext thisCallContext) {
-        return ClientStreamingCallable.this.clientStreamingCall(
-            responseObserver, defaultCallContext.merge(thisCallContext));
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/DataLossException.java b/gax/src/main/java/com/google/api/gax/rpc/DataLossException.java
deleted file mode 100644
index e3d9a8107..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/DataLossException.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** Exception thrown due to unrecoverable data loss or corruption. */
-public class DataLossException extends ApiException {
-  public DataLossException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public DataLossException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public DataLossException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/DeadlineExceededException.java b/gax/src/main/java/com/google/api/gax/rpc/DeadlineExceededException.java
deleted file mode 100644
index 37b5d8db0..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/DeadlineExceededException.java
+++ /dev/null
@@ -1,52 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when deadline expired before operation could complete. For operations that
- * change the state of the system, this error may be returned even if the operation has completed
- * successfully. For example, a successful response from a server could have been delayed long
- * enough for the deadline to expire.
- */
-public class DeadlineExceededException extends ApiException {
-  public DeadlineExceededException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public DeadlineExceededException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public DeadlineExceededException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ErrorDetails.java b/gax/src/main/java/com/google/api/gax/rpc/ErrorDetails.java
deleted file mode 100644
index 09c924b59..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ErrorDetails.java
+++ /dev/null
@@ -1,166 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.auto.value.AutoValue;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.protobuf.Any;
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.Message;
-import com.google.rpc.BadRequest;
-import com.google.rpc.DebugInfo;
-import com.google.rpc.ErrorInfo;
-import com.google.rpc.Help;
-import com.google.rpc.LocalizedMessage;
-import com.google.rpc.PreconditionFailure;
-import com.google.rpc.QuotaFailure;
-import com.google.rpc.RequestInfo;
-import com.google.rpc.ResourceInfo;
-import com.google.rpc.RetryInfo;
-import java.util.List;
-import javax.annotation.Nullable;
-
-/** This class contains a list of standard error messages that returns from server. */
-@AutoValue
-public abstract class ErrorDetails {
-
-  /**
-   * This is the most important and special error message. It describes the cause of the error with
-   * structured details that both humans and applications can depend on.
-   */
-  @Nullable
-  public ErrorInfo getErrorInfo() {
-    return unpack(ErrorInfo.class);
-  }
-
-  /**
-   * Describes when the clients can retry a failed request. Clients could ignore the recommendation
-   * here or retry when this information is missing from error responses.
-   */
-  @Nullable
-  public RetryInfo getRetryInfo() {
-    return unpack(RetryInfo.class);
-  }
-
-  /** Describes additional debugging info. */
-  @Nullable
-  public DebugInfo getDebugInfo() {
-    return unpack(DebugInfo.class);
-  }
-
-  /** Describes how a quota check failed. */
-  @Nullable
-  public QuotaFailure getQuotaFailure() {
-    return unpack(QuotaFailure.class);
-  }
-
-  /** Describes what preconditions have failed. */
-  @Nullable
-  public PreconditionFailure getPreconditionFailure() {
-    return unpack(PreconditionFailure.class);
-  }
-
-  /**
-   * Describes violations in a client request. This error type focuses on the syntactic aspects of
-   * the request.
-   */
-  @Nullable
-  public BadRequest getBadRequest() {
-    return unpack(BadRequest.class);
-  }
-
-  /**
-   * Contains metadata about the request that clients can attach when filing a bug or providing
-   * other forms of feedback.
-   */
-  @Nullable
-  public RequestInfo getRequestInfo() {
-    return unpack(RequestInfo.class);
-  }
-
-  /** Describes the resource that is being accessed. */
-  @Nullable
-  public ResourceInfo getResourceInfo() {
-    return unpack(ResourceInfo.class);
-  }
-
-  /** Provides links to documentation or for performing an out-of-band action. */
-  @Nullable
-  public Help getHelp() {
-    return unpack(Help.class);
-  }
-
-  /**
-   * Provides a localized error message that is safe to return to the user which can be attached to
-   * an RPC error
-   */
-  @Nullable
-  public LocalizedMessage getLocalizedMessage() {
-    return unpack(LocalizedMessage.class);
-  }
-
-  /** This is a list of raw/unparsed error messages that returns from server. */
-  @Nullable
-  abstract List<Any> getRawErrorMessages();
-
-  public static Builder builder() {
-    return new AutoValue_ErrorDetails.Builder();
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-
-    public abstract Builder setRawErrorMessages(List<Any> rawErrorMessages);
-
-    public abstract ErrorDetails build();
-  }
-
-  @VisibleForTesting
-  <T extends Message> T unpack(Class<T> errorTypeClazz) {
-    List<Any> rawErrorMessages = getRawErrorMessages();
-    if (rawErrorMessages == null) {
-      return null;
-    }
-    for (Any detail : rawErrorMessages) {
-      if (!detail.is(errorTypeClazz)) {
-        continue;
-      }
-      try {
-        return detail.unpack(errorTypeClazz);
-      } catch (InvalidProtocolBufferException e) {
-        throw new ProtocolBufferParsingException(
-            String.format(
-                "Failed to unpack %s from raw error messages", errorTypeClazz.getSimpleName()),
-            e);
-      }
-    }
-    return null;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FailedPreconditionException.java b/gax/src/main/java/com/google/api/gax/rpc/FailedPreconditionException.java
deleted file mode 100644
index e1b3ec75e..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FailedPreconditionException.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the operation was rejected because the system is not in a state required
- * for the operation's execution. For example, directory to be deleted may be non-empty, an rmdir
- * operation is applied to a non-directory, etc.
- */
-public class FailedPreconditionException extends ApiException {
-  public FailedPreconditionException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public FailedPreconditionException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public FailedPreconditionException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FirstElementCallable.java b/gax/src/main/java/com/google/api/gax/rpc/FirstElementCallable.java
deleted file mode 100644
index 3446e9ffc..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FirstElementCallable.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-
-/**
- * Wraps a {@link ServerStreamingCallable} in a {@link UnaryCallable} that returns the first
- * element. After returning the first element, the underlying stream will be gracefully cancelled.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> The type of the request.
- * @param <ResponseT> The type of the item in the stream.
- */
-final class FirstElementCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final ServerStreamingCallable<RequestT, ResponseT> streamingCallable;
-
-  FirstElementCallable(ServerStreamingCallable<RequestT, ResponseT> streamingCallable) {
-    this.streamingCallable = streamingCallable;
-  }
-
-  /**
-   * Starts the RPC and returns a future wrapping the result. If the stream is empty, the result
-   * will be null. If a request is cancelled, the future will be rejected with a {@link
-   * java.util.concurrent.CancellationException}.
-   *
-   * @param request The request.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return A {@link ApiFuture} wrapping a possible first element of the stream.
-   */
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-    FirstElementResponseObserver<ResponseT> observer = new FirstElementResponseObserver<>();
-
-    streamingCallable.call(request, observer, context);
-    // NOTE: Since onStart must be called synchronously on this thread, the observer is now fully
-    // initialized and the future can be safely returned to the caller.
-    return observer.getFuture();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FirstElementResponseObserver.java b/gax/src/main/java/com/google/api/gax/rpc/FirstElementResponseObserver.java
deleted file mode 100644
index d6e250176..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FirstElementResponseObserver.java
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-
-/**
- * A {@link ResponseObserver} that wraps a future. The future will resolved upon receiving the first
- * element or exhausting the streaming.
- *
- * <p>Package-private for internal use.
- *
- * @param <ResponseT> The type of the element in the stream.
- */
-class FirstElementResponseObserver<ResponseT> extends StateCheckingResponseObserver<ResponseT> {
-  private final MyFuture future = new MyFuture();
-  private StreamController controller;
-
-  @Override
-  protected void onStartImpl(StreamController controller) {
-    // NOTE: the call is started before the future is exposed to the caller
-    this.controller = controller;
-
-    controller.disableAutoInboundFlowControl();
-    controller.request(1);
-  }
-
-  @Override
-  protected void onResponseImpl(ResponseT response) {
-    future.set(response);
-    controller.cancel();
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    future.setException(t);
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    future.set(null);
-  }
-
-  ApiFuture<ResponseT> getFuture() {
-    return future;
-  }
-
-  /** Simple implementation of a future that allows the receiver to cancel the underlying stream. */
-  private class MyFuture extends AbstractApiFuture<ResponseT> {
-    @Override
-    protected void interruptTask() {
-      FirstElementResponseObserver.this.controller.cancel();
-    }
-
-    @Override
-    protected boolean set(ResponseT value) {
-      return super.set(value);
-    }
-
-    @Override
-    protected boolean setException(Throwable throwable) {
-      return super.setException(throwable);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FixedHeaderProvider.java b/gax/src/main/java/com/google/api/gax/rpc/FixedHeaderProvider.java
deleted file mode 100644
index 8aa781697..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FixedHeaderProvider.java
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.auto.value.AutoValue;
-import com.google.common.collect.ImmutableMap;
-import java.io.Serializable;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import javax.annotation.Nullable;
-
-/** An instance of HeaderProvider that always provides the same headers. */
-@AutoValue
-public abstract class FixedHeaderProvider implements HeaderProvider, Serializable {
-
-  private static final long serialVersionUID = -4881534091594970538L;
-
-  @Override
-  @Nullable
-  public abstract Map<String, String> getHeaders();
-
-  /** Creates a FixedHeaderProvider. */
-  public static FixedHeaderProvider create(Map<String, String> headers) {
-    checkKeys(headers.keySet());
-    return new AutoValue_FixedHeaderProvider(ImmutableMap.copyOf(headers));
-  }
-
-  public static FixedHeaderProvider create(String... keyValuePairs) {
-    if (keyValuePairs.length % 2 != 0) {
-      throw new IllegalArgumentException(
-          "The keyValuePairs var-arg parameter must contain an even number of elements");
-    }
-    ImmutableMap.Builder<String, String> headersBuilder = ImmutableMap.builder();
-    for (int i = 0; i < keyValuePairs.length; i += 2) {
-      headersBuilder.put(keyValuePairs[i], keyValuePairs[i + 1]);
-    }
-    Map<String, String> headers = headersBuilder.build();
-
-    checkKeys(headers.keySet());
-    return new AutoValue_FixedHeaderProvider(headers);
-  }
-
-  private static void checkKeys(Collection<String> keys) {
-    Set<String> caseInsensitiveKeys = new HashSet<>();
-    for (String key : keys) {
-      if (!caseInsensitiveKeys.add(key.toLowerCase())) {
-        throw new IllegalArgumentException(
-            "The header key '" + key + "' is not case insensitively unique");
-      }
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FixedTransportChannelProvider.java b/gax/src/main/java/com/google/api/gax/rpc/FixedTransportChannelProvider.java
deleted file mode 100644
index 0bf6205dd..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FixedTransportChannelProvider.java
+++ /dev/null
@@ -1,132 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.auth.Credentials;
-import com.google.common.base.Preconditions;
-import java.io.IOException;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-
-/** An instance of TransportChannelProvider that always provides the same TransportChannel. */
-@InternalExtensionOnly
-public class FixedTransportChannelProvider implements TransportChannelProvider {
-
-  private final TransportChannel transportChannel;
-
-  private FixedTransportChannelProvider(TransportChannel transportChannel) {
-    this.transportChannel = Preconditions.checkNotNull(transportChannel);
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return false;
-  }
-
-  @Override
-  public boolean needsExecutor() {
-    return false;
-  }
-
-  @Override
-  public FixedTransportChannelProvider withExecutor(ScheduledExecutorService executor) {
-    return withExecutor((Executor) executor);
-  }
-
-  @Override
-  public FixedTransportChannelProvider withExecutor(Executor executor) {
-    throw new UnsupportedOperationException(
-        "FixedTransportChannelProvider doesn't need an executor");
-  }
-
-  @Override
-  public boolean needsHeaders() {
-    return false;
-  }
-
-  @Override
-  public FixedTransportChannelProvider withHeaders(Map<String, String> headers) {
-    throw new UnsupportedOperationException("FixedTransportChannelProvider doesn't need headers");
-  }
-
-  @Override
-  public boolean needsEndpoint() {
-    return false;
-  }
-
-  @Override
-  public TransportChannelProvider withEndpoint(String endpoint) {
-    throw new UnsupportedOperationException(
-        "FixedTransportChannelProvider doesn't need an endpoint");
-  }
-
-  /** @deprecated FixedTransportChannelProvider doesn't support ChannelPool configuration */
-  @Deprecated
-  @Override
-  public boolean acceptsPoolSize() {
-    return false;
-  }
-
-  /** @deprecated FixedTransportChannelProvider doesn't support ChannelPool configuration */
-  @Deprecated
-  @Override
-  public TransportChannelProvider withPoolSize(int size) {
-    throw new UnsupportedOperationException(
-        "FixedTransportChannelProvider doesn't allow pool size customization");
-  }
-
-  @Override
-  public TransportChannel getTransportChannel() throws IOException {
-    return transportChannel;
-  }
-
-  @Override
-  public String getTransportName() {
-    return transportChannel.getTransportName();
-  }
-
-  @Override
-  public boolean needsCredentials() {
-    return false;
-  }
-
-  @Override
-  public TransportChannelProvider withCredentials(Credentials credentials) {
-    throw new UnsupportedOperationException(
-        "FixedTransportChannelProvider doesn't need credentials");
-  }
-
-  /** Creates a FixedTransportChannelProvider. */
-  public static FixedTransportChannelProvider create(TransportChannel transportChannel) {
-    return new FixedTransportChannelProvider(transportChannel);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/FixedWatchdogProvider.java b/gax/src/main/java/com/google/api/gax/rpc/FixedWatchdogProvider.java
deleted file mode 100644
index a1fd245b5..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/FixedWatchdogProvider.java
+++ /dev/null
@@ -1,97 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.InternalApi;
-import java.util.concurrent.ScheduledExecutorService;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * A watchdog provider which always returns the same watchdog instance provided to the provider
- * during construction.
- *
- * <p>This is the internal class and is public only for technical reasons. It may change any time
- * without notice, please do not depend on it explicitly.
- */
-@InternalApi
-public final class FixedWatchdogProvider implements WatchdogProvider {
-  @Nullable private final Watchdog watchdog;
-
-  public static WatchdogProvider create(Watchdog watchdog) {
-    return new FixedWatchdogProvider(watchdog);
-  }
-
-  private FixedWatchdogProvider(Watchdog watchdog) {
-    this.watchdog = watchdog;
-  }
-
-  @Override
-  public boolean needsClock() {
-    return false;
-  }
-
-  @Override
-  public WatchdogProvider withClock(@Nonnull ApiClock clock) {
-    throw new UnsupportedOperationException("FixedWatchdogProvider doesn't need a clock");
-  }
-
-  @Override
-  public boolean needsCheckInterval() {
-    return false;
-  }
-
-  @Override
-  public WatchdogProvider withCheckInterval(Duration checkInterval) {
-    throw new UnsupportedOperationException("FixedWatchdogProvider doesn't need a checkInterval");
-  }
-
-  @Override
-  public boolean needsExecutor() {
-    return false;
-  }
-
-  @Override
-  public WatchdogProvider withExecutor(ScheduledExecutorService executor) {
-    throw new UnsupportedOperationException("FixedWatchdogProvider doesn't need an executor");
-  }
-
-  @Override
-  public Watchdog getWatchdog() {
-    return watchdog;
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return false;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/HeaderProvider.java b/gax/src/main/java/com/google/api/gax/rpc/HeaderProvider.java
deleted file mode 100644
index c20351c0a..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/HeaderProvider.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import java.util.Map;
-
-/** Provider of headers to put on http requests. */
-public interface HeaderProvider {
-
-  /** Get the headers to put on http requests. */
-  Map<String, String> getHeaders();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/InstantiatingWatchdogProvider.java b/gax/src/main/java/com/google/api/gax/rpc/InstantiatingWatchdogProvider.java
deleted file mode 100644
index a069c49c8..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/InstantiatingWatchdogProvider.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.InternalApi;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.ScheduledExecutorService;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * A watchdog provider which instantiates a new provider on every request.
- *
- * <p>This is the internal class and is public only for technical reasons. It may change any time
- * without notice, please do not depend on it explicitly.
- */
-@InternalApi
-public final class InstantiatingWatchdogProvider implements WatchdogProvider {
-  @Nullable private final ApiClock clock;
-  @Nullable private final ScheduledExecutorService executor;
-  @Nullable private final Duration checkInterval;
-
-  public static WatchdogProvider create() {
-    return new InstantiatingWatchdogProvider(null, null, null);
-  }
-
-  private InstantiatingWatchdogProvider(
-      @Nullable ApiClock clock,
-      @Nullable ScheduledExecutorService executor,
-      @Nullable Duration checkInterval) {
-    this.clock = clock;
-    this.executor = executor;
-    this.checkInterval = checkInterval;
-  }
-
-  @Override
-  public boolean needsClock() {
-    return clock == null;
-  }
-
-  @Override
-  public WatchdogProvider withClock(@Nonnull ApiClock clock) {
-    return new InstantiatingWatchdogProvider(
-        Preconditions.checkNotNull(clock), executor, checkInterval);
-  }
-
-  @Override
-  public boolean needsCheckInterval() {
-    return checkInterval == null;
-  }
-
-  @Override
-  public WatchdogProvider withCheckInterval(@Nonnull Duration checkInterval) {
-    return new InstantiatingWatchdogProvider(
-        clock, executor, Preconditions.checkNotNull(checkInterval));
-  }
-
-  @Override
-  public boolean needsExecutor() {
-    return executor == null;
-  }
-
-  @Override
-  public WatchdogProvider withExecutor(ScheduledExecutorService executor) {
-    return new InstantiatingWatchdogProvider(
-        clock, Preconditions.checkNotNull(executor), checkInterval);
-  }
-
-  @SuppressWarnings("ConstantConditions")
-  @Nullable
-  @Override
-  public Watchdog getWatchdog() {
-    Preconditions.checkState(!needsClock(), "A clock is needed");
-    Preconditions.checkState(!needsCheckInterval(), "A check interval is needed");
-    Preconditions.checkState(!needsExecutor(), "An executor is needed");
-
-    // Watchdog is disabled
-    if (checkInterval.isZero()) {
-      return null;
-    }
-
-    return Watchdog.create(clock, checkInterval, executor);
-  }
-
-  @Override
-  public boolean shouldAutoClose() {
-    return true;
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/InternalException.java b/gax/src/main/java/com/google/api/gax/rpc/InternalException.java
deleted file mode 100644
index 3d5763f06..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/InternalException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown due to internal errors. Means some invariants expected by underlying system has
- * been broken. If you see one of these errors, something is very broken.
- */
-public class InternalException extends ApiException {
-  public InternalException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public InternalException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public InternalException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/InvalidArgumentException.java b/gax/src/main/java/com/google/api/gax/rpc/InvalidArgumentException.java
deleted file mode 100644
index 6b0ccc6f6..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/InvalidArgumentException.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when client specified an invalid argument. Note that this differs from {@link
- * FailedPreconditionException}. This exception indicates arguments that are problematic regardless
- * of the state of the system (e.g., a malformed file name).
- */
-public class InvalidArgumentException extends ApiException {
-  public InvalidArgumentException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public InvalidArgumentException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public InvalidArgumentException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/LongRunningClient.java b/gax/src/main/java/com/google/api/gax/rpc/LongRunningClient.java
deleted file mode 100644
index 87ebd2611..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/LongRunningClient.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.longrunning.OperationSnapshot;
-
-/** Implementation-agnostic interface for managing long-running operations. */
-public interface LongRunningClient {
-
-  /**
-   * Returns a {@link UnaryCallable} which can issue calls to get the latest state of an operation.
-   */
-  UnaryCallable<String, OperationSnapshot> getOperationCallable();
-
-  /** Returns a {@link UnaryCallable} which can issue calls to cancel an operation. */
-  UnaryCallable<String, Void> cancelOperationCallable();
-
-  /** Returns a {@link UnaryCallable} which can issue calls to delete an operation. */
-  UnaryCallable<String, Void> deleteOperationCallable();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/NoHeaderProvider.java b/gax/src/main/java/com/google/api/gax/rpc/NoHeaderProvider.java
deleted file mode 100644
index 48b8532ea..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/NoHeaderProvider.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import java.io.Serializable;
-import java.util.Collections;
-import java.util.Map;
-
-/** Implementation of HeaderProvider that provides empty headers. */
-public class NoHeaderProvider implements HeaderProvider, Serializable {
-  private static final long serialVersionUID = 7323717933589691233L;
-
-  @Override
-  public Map<String, String> getHeaders() {
-    return Collections.emptyMap();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/NotFoundException.java b/gax/src/main/java/com/google/api/gax/rpc/NotFoundException.java
deleted file mode 100644
index ce8b0b1d7..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/NotFoundException.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** Exception thrown when some requested entity (e.g., file or directory) was not found. */
-public class NotFoundException extends ApiException {
-  public NotFoundException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public NotFoundException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public NotFoundException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/OperationCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/OperationCallSettings.java
deleted file mode 100644
index 0236f59a5..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/OperationCallSettings.java
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.TimedRetryAlgorithm;
-
-/**
- * A settings class to configure an {@link OperationCallable} for calls to initiate, resume, and
- * cancel a long-running operation.
- */
-public final class OperationCallSettings<RequestT, ResponseT, MetadataT> {
-  private final UnaryCallSettings<RequestT, OperationSnapshot> initialCallSettings;
-  private final TimedRetryAlgorithm pollingAlgorithm;
-  private final ApiFunction<OperationSnapshot, ResponseT> responseTransformer;
-  private final ApiFunction<OperationSnapshot, MetadataT> metadataTransformer;
-
-  public final UnaryCallSettings<RequestT, OperationSnapshot> getInitialCallSettings() {
-    return initialCallSettings;
-  }
-
-  public final TimedRetryAlgorithm getPollingAlgorithm() {
-    return pollingAlgorithm;
-  }
-
-  public final ApiFunction<OperationSnapshot, ResponseT> getResponseTransformer() {
-    return responseTransformer;
-  }
-
-  public final ApiFunction<OperationSnapshot, MetadataT> getMetadataTransformer() {
-    return metadataTransformer;
-  }
-
-  private OperationCallSettings(
-      UnaryCallSettings<RequestT, OperationSnapshot> initialCallSettings,
-      TimedRetryAlgorithm pollingAlgorithm,
-      ApiFunction<OperationSnapshot, ResponseT> responseTransformer,
-      ApiFunction<OperationSnapshot, MetadataT> metadataTransformer) {
-    this.initialCallSettings = checkNotNull(initialCallSettings);
-    this.pollingAlgorithm = checkNotNull(pollingAlgorithm);
-    this.responseTransformer = checkNotNull(responseTransformer);
-    this.metadataTransformer = metadataTransformer;
-  }
-
-  /** Create a new builder which can construct an instance of OperationCallSettings. */
-  public static <RequestT, ResponseT, MetadataT>
-      Builder<RequestT, ResponseT, MetadataT> newBuilder() {
-    return new Builder<>();
-  }
-
-  public final Builder<RequestT, ResponseT, MetadataT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  public static class Builder<RequestT, ResponseT, MetadataT> {
-    private UnaryCallSettings<RequestT, OperationSnapshot> initialCallSettings;
-    private TimedRetryAlgorithm pollingAlgorithm;
-    private ApiFunction<OperationSnapshot, ResponseT> responseTransformer;
-    private ApiFunction<OperationSnapshot, MetadataT> metadataTransformer;
-
-    public Builder() {}
-
-    public Builder(OperationCallSettings<RequestT, ResponseT, MetadataT> settings) {
-      this.initialCallSettings = settings.initialCallSettings.toBuilder().build();
-      this.pollingAlgorithm = settings.pollingAlgorithm;
-      this.responseTransformer = settings.responseTransformer;
-      this.metadataTransformer = settings.metadataTransformer;
-    }
-
-    /** Set the polling algorithm of the operation. */
-    public Builder<RequestT, ResponseT, MetadataT> setPollingAlgorithm(
-        TimedRetryAlgorithm pollingAlgorithm) {
-      this.pollingAlgorithm = pollingAlgorithm;
-      return this;
-    }
-
-    /** Get the polling algorithm of the operation. */
-    public TimedRetryAlgorithm getPollingAlgorithm() {
-      return pollingAlgorithm;
-    }
-
-    /** Set the call settings which are used on the call to initiate the operation. */
-    public Builder<RequestT, ResponseT, MetadataT> setInitialCallSettings(
-        UnaryCallSettings<RequestT, OperationSnapshot> initialCallSettings) {
-      this.initialCallSettings = initialCallSettings;
-      return this;
-    }
-
-    /** Get the call settings which are used on the call to initiate the operation. */
-    public UnaryCallSettings<RequestT, OperationSnapshot> getInitialCallSettings() {
-      return initialCallSettings;
-    }
-
-    public final ApiFunction<OperationSnapshot, ResponseT> getResponseTransformer() {
-      return responseTransformer;
-    }
-
-    public Builder<RequestT, ResponseT, MetadataT> setResponseTransformer(
-        ApiFunction<OperationSnapshot, ResponseT> responseTransformer) {
-      this.responseTransformer = responseTransformer;
-      return this;
-    }
-
-    public final ApiFunction<OperationSnapshot, MetadataT> getMetadataTransformer() {
-      return metadataTransformer;
-    }
-
-    public Builder<RequestT, ResponseT, MetadataT> setMetadataTransformer(
-        ApiFunction<OperationSnapshot, MetadataT> metadataTransformer) {
-      this.metadataTransformer = metadataTransformer;
-      return this;
-    }
-
-    public OperationCallSettings<RequestT, ResponseT, MetadataT> build() {
-      return new OperationCallSettings<>(
-          initialCallSettings, pollingAlgorithm, responseTransformer, metadataTransformer);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/OperationCallable.java b/gax/src/main/java/com/google/api/gax/rpc/OperationCallable.java
deleted file mode 100644
index 75eac0e92..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/OperationCallable.java
+++ /dev/null
@@ -1,166 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.longrunning.OperationFuture;
-
-/**
- * An OperationCallable is an immutable object which is capable of initiating RPC calls to
- * long-running API methods and returning an {@link OperationFuture} to manage the polling of the
- * Operation and getting the response.
- *
- * <p>It is considered advanced usage for a user to create an OperationCallable themselves. This
- * class is intended to be created by a generated client class, and configured by instances of
- * OperationCallSettings.Builder which are exposed through the client settings class.
- */
-public abstract class OperationCallable<RequestT, ResponseT, MetadataT> {
-
-  protected OperationCallable() {}
-
-  /**
-   * Initiates an operation asynchronously.
-   *
-   * @param request The request to initiate the operation.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return {@link OperationFuture} for the call result
-   */
-  public abstract OperationFuture<ResponseT, MetadataT> futureCall(
-      RequestT request, ApiCallContext context);
-
-  /**
-   * Same as {@link #futureCall(Object, ApiCallContext)}, with a null context.
-   *
-   * @param request request
-   * @return {@link ApiFuture} for the call result
-   */
-  public OperationFuture<ResponseT, MetadataT> futureCall(RequestT request) {
-    return futureCall(request, null);
-  }
-
-  /**
-   * Perform a call synchronously.
-   *
-   * @param request The request to initiate the operation.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return the call result
-   * @throws ApiException if there is any bad status in the response.
-   * @throws RuntimeException if there is any other exception unrelated to bad status.
-   */
-  public ResponseT call(RequestT request, ApiCallContext context) {
-    return ApiExceptions.callAndTranslateApiException(futureCall(request, context));
-  }
-
-  /**
-   * Same as {@link #call(Object, ApiCallContext)}, with a null context.
-   *
-   * @param request The request to initiate the operation.
-   * @return the call result
-   * @throws ApiException if there is any bad status in the response.
-   * @throws RuntimeException if there is any other exception unrelated to bad status.
-   */
-  public ResponseT call(RequestT request) {
-    return ApiExceptions.callAndTranslateApiException(futureCall(request));
-  }
-
-  /**
-   * Creates a new {@link OperationFuture} to watch an operation that has been initiated previously.
-   * Note: This is not type-safe at static time; the result type can only be checked once the
-   * operation finishes.
-   *
-   * @param operationName The name of the operation to resume.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return {@link OperationFuture} for the call result.
-   */
-  public abstract OperationFuture<ResponseT, MetadataT> resumeFutureCall(
-      String operationName, ApiCallContext context);
-
-  /**
-   * Creates a new {@link OperationFuture} to watch an operation that has been initiated previously.
-   * Note: This is not type-safe at static time; the result type can only be checked once the
-   * operation finishes.
-   *
-   * @param operationName The name of the operation to resume.
-   * @return {@link OperationFuture} for the call result.
-   */
-  public OperationFuture<ResponseT, MetadataT> resumeFutureCall(String operationName) {
-    return resumeFutureCall(operationName, null);
-  }
-
-  /**
-   * Sends a cancellation request to the server for the operation with name {@code operationName}.
-   *
-   * @param operationName The name of the operation to cancel.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return the future which completes once the operation is canceled on the server side.
-   */
-  public abstract ApiFuture<Void> cancel(String operationName, ApiCallContext context);
-
-  /**
-   * Sends a cancellation request to the server for the operation with name {@code operationName}.
-   *
-   * @param operationName The name of the operation to cancel.
-   * @return the future which completes once the operation is canceled on the server side.
-   */
-  public ApiFuture<Void> cancel(String operationName) {
-    return cancel(operationName, null);
-  }
-
-  /**
-   * Returns a new {@code OperationCallable} with an {@link ApiCallContext} that is used as a
-   * default when none is supplied in individual calls.
-   *
-   * @param defaultCallContext the default {@link ApiCallContext}.
-   */
-  public OperationCallable<RequestT, ResponseT, MetadataT> withDefaultCallContext(
-      final ApiCallContext defaultCallContext) {
-    return new OperationCallable<RequestT, ResponseT, MetadataT>() {
-      @Override
-      public OperationFuture<ResponseT, MetadataT> futureCall(
-          RequestT request, ApiCallContext thisCallContext) {
-        return OperationCallable.this.futureCall(
-            request, defaultCallContext.merge(thisCallContext));
-      }
-
-      @Override
-      public OperationFuture<ResponseT, MetadataT> resumeFutureCall(
-          String operationName, ApiCallContext thisCallContext) {
-        return OperationCallable.this.resumeFutureCall(
-            operationName, defaultCallContext.merge(thisCallContext));
-      }
-
-      @Override
-      public ApiFuture<Void> cancel(String operationName, ApiCallContext thisCallContext) {
-        return OperationCallable.this.cancel(
-            operationName, defaultCallContext.merge(thisCallContext));
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/OperationCallableImpl.java b/gax/src/main/java/com/google/api/gax/rpc/OperationCallableImpl.java
deleted file mode 100644
index f1161851b..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/OperationCallableImpl.java
+++ /dev/null
@@ -1,129 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.longrunning.OperationFutureImpl;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.RetryingExecutorWithContext;
-import com.google.api.gax.retrying.RetryingFuture;
-
-/**
- * An OperationCallableImpl is an immutable object which is capable of initiating RPC calls to
- * long-running API methods and returning a {@link OperationFuture} to manage the polling of the
- * Operation and getting the response.
- *
- * <p>Package-private for internal use.
- */
-class OperationCallableImpl<RequestT, ResponseT, MetadataT>
-    extends OperationCallable<RequestT, ResponseT, MetadataT> {
-
-  private final UnaryCallable<RequestT, OperationSnapshot> initialCallable;
-  private final RetryingExecutorWithContext<OperationSnapshot> executor;
-  private final LongRunningClient longRunningClient;
-  private final ApiFunction<OperationSnapshot, ResponseT> responseTransformer;
-  private final ApiFunction<OperationSnapshot, MetadataT> metadataTransformer;
-
-  OperationCallableImpl(
-      UnaryCallable<RequestT, OperationSnapshot> initialCallable,
-      RetryingExecutorWithContext<OperationSnapshot> executor,
-      LongRunningClient longRunningClient,
-      OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings) {
-    this.initialCallable = checkNotNull(initialCallable);
-    this.executor = checkNotNull(executor);
-    this.longRunningClient = checkNotNull(longRunningClient);
-    this.responseTransformer = operationCallSettings.getResponseTransformer();
-    this.metadataTransformer = operationCallSettings.getMetadataTransformer();
-  }
-
-  /**
-   * Initiates an operation asynchronously. If the {@link TransportChannel} encapsulated in the
-   * given {@link ApiCallContext} is null, a channel must have already been bound at construction
-   * time.
-   *
-   * @param request The request to initiate the operation.
-   * @param callContext {@link ApiCallContext} to make the call with
-   * @return {@link OperationFuture} for the call result
-   */
-  @Override
-  public OperationFuture<ResponseT, MetadataT> futureCall(
-      RequestT request, ApiCallContext callContext) {
-    ApiFuture<OperationSnapshot> initialFuture = initialCallable.futureCall(request, callContext);
-    return futureCall(initialFuture, callContext);
-  }
-
-  /** Waits for the initialFuture to resolve and then starts to poll the return operation. */
-  OperationFutureImpl<ResponseT, MetadataT> futureCall(
-      ApiFuture<OperationSnapshot> initialFuture, ApiCallContext callContext) {
-
-    RecheckingCallable<RequestT, OperationSnapshot> callable =
-        new RecheckingCallable<>(
-            new OperationCheckingCallable<RequestT>(longRunningClient, initialFuture), executor);
-
-    // NOTE: OperationCheckingCallable will compose its own request using the resolved
-    // initialFuture. So the request parameter to futureCall is ignored
-    RetryingFuture<OperationSnapshot> pollingFuture = callable.futureCall(null, callContext);
-    return new OperationFutureImpl<>(
-        pollingFuture, initialFuture, responseTransformer, metadataTransformer);
-  }
-
-  /**
-   * Creates a new {@link OperationFuture} to watch an operation that has been initiated previously.
-   * Note: This is not type-safe at static time; the result type can only be checked once the
-   * operation finishes.
-   *
-   * @param operationName The name of the operation to resume.
-   * @param callContext {@link ApiCallContext} to make the call with
-   * @return {@link OperationFuture} for the call result.
-   */
-  @Override
-  public OperationFuture<ResponseT, MetadataT> resumeFutureCall(
-      String operationName, ApiCallContext callContext) {
-    ApiFuture<OperationSnapshot> firstAttempt =
-        longRunningClient.getOperationCallable().futureCall(operationName, callContext);
-    return futureCall(firstAttempt, callContext);
-  }
-
-  /**
-   * Sends a cancellation request to the server for the operation with name {@code operationName}.
-   *
-   * @param operationName The name of the operation to cancel.
-   * @param callContext {@link ApiCallContext} to make the call with
-   * @return the future which completes once the operation is canceled on the server side.
-   */
-  @Override
-  public ApiFuture<Void> cancel(String operationName, ApiCallContext callContext) {
-    return longRunningClient.cancelOperationCallable().futureCall(operationName, callContext);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/OperationCheckingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/OperationCheckingCallable.java
deleted file mode 100644
index 302e0fbae..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/OperationCheckingCallable.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import java.util.concurrent.ExecutionException;
-
-/**
- * A future callable which relies on callback chaining to execute server polling (asking for a
- * status of a specific operation: in progress, completed, canceled etc.). This implementation is
- * called from {@link AttemptCallable}, essentially using for polling the same logic which is used
- * for retrying.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> type of the request
- */
-class OperationCheckingCallable<RequestT> extends UnaryCallable<RequestT, OperationSnapshot> {
-  private final LongRunningClient longRunningClient;
-  private final ApiFuture<OperationSnapshot> initialFuture;
-
-  OperationCheckingCallable(
-      LongRunningClient longRunningClient, ApiFuture<OperationSnapshot> initialFuture) {
-    this.longRunningClient = checkNotNull(longRunningClient);
-    this.initialFuture = checkNotNull(initialFuture);
-  }
-
-  /**
-   * This method is supposed to be called from {@link AttemptCallable#call()}
-   *
-   * @param ignored The ignored request; the actual request will be composed based on the result of
-   *     the {@code initialFuture}.
-   * @param callContext call context
-   */
-  @Override
-  public ApiFuture<OperationSnapshot> futureCall(RequestT ignored, ApiCallContext callContext) {
-    try {
-      if (!initialFuture.isDone() || initialFuture.isCancelled()) {
-        return initialFuture;
-      }
-      // Since initialFuture is done at this point, the following call should be non-blocking
-      OperationSnapshot initialOperation = initialFuture.get();
-
-      if (initialOperation.isDone()) {
-        return initialFuture;
-      }
-
-      return longRunningClient
-          .getOperationCallable()
-          .futureCall(initialOperation.getName(), callContext);
-    } catch (ExecutionException e) {
-      return ApiFutures.immediateFailedFuture(e.getCause());
-    } catch (InterruptedException e) {
-      return ApiFutures.immediateFailedFuture(e);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/OutOfRangeException.java b/gax/src/main/java/com/google/api/gax/rpc/OutOfRangeException.java
deleted file mode 100644
index 33ecb38ca..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/OutOfRangeException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the operation was attempted past the valid range. E.g., seeking or reading
- * past end of file.
- */
-public class OutOfRangeException extends ApiException {
-  public OutOfRangeException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public OutOfRangeException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public OutOfRangeException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PageContext.java b/gax/src/main/java/com/google/api/gax/rpc/PageContext.java
deleted file mode 100644
index a58238881..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PageContext.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.auto.value.AutoValue;
-
-/** The context for a page call. */
-@AutoValue
-public abstract class PageContext<RequestT, ResponseT, ResourceT> {
-
-  public abstract UnaryCallable<RequestT, ResponseT> getCallable();
-
-  public abstract PagedListDescriptor<RequestT, ResponseT, ResourceT> getPageDescriptor();
-
-  public abstract RequestT getRequest();
-
-  public abstract ApiCallContext getCallContext();
-
-  public PageContext<RequestT, ResponseT, ResourceT> withRequest(RequestT newRequest) {
-    return new AutoValue_PageContext<>(
-        getCallable(), getPageDescriptor(), newRequest, getCallContext());
-  }
-
-  public static <RequestT, ResponseT, ResourceT> PageContext<RequestT, ResponseT, ResourceT> create(
-      UnaryCallable<RequestT, ResponseT> callable,
-      PagedListDescriptor<RequestT, ResponseT, ResourceT> pageDescriptor,
-      RequestT request,
-      ApiCallContext callContext) {
-    return new AutoValue_PageContext<>(callable, pageDescriptor, request, callContext);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PagedCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/PagedCallSettings.java
deleted file mode 100644
index cff1ed0b7..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PagedCallSettings.java
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.retrying.RetrySettings;
-import java.util.Set;
-
-/**
- * A settings class to configure a {@link UnaryCallable} for calls to an API method that supports
- * page streaming.
- */
-@InternalExtensionOnly
-public final class PagedCallSettings<RequestT, ResponseT, PagedListResponseT>
-    extends UnaryCallSettings<RequestT, ResponseT> {
-  private final PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-      pagedListResponseFactory;
-
-  public PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-      getPagedListResponseFactory() {
-    return pagedListResponseFactory;
-  }
-
-  public static <RequestT, ResponseT, PagedListResponseT>
-      Builder<RequestT, ResponseT, PagedListResponseT> newBuilder(
-          PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-              pagedListResponseFactory) {
-    return new Builder<>(pagedListResponseFactory);
-  }
-
-  @Override
-  public final Builder<RequestT, ResponseT, PagedListResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  private PagedCallSettings(Builder<RequestT, ResponseT, PagedListResponseT> builder) {
-    super(builder);
-    this.pagedListResponseFactory = builder.pagedListResponseFactory;
-  }
-
-  public static class Builder<RequestT, ResponseT, PagedListResponseT>
-      extends UnaryCallSettings.Builder<RequestT, ResponseT> {
-    private PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-        pagedListResponseFactory;
-
-    public Builder(
-        PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-            pagedListResponseFactory) {
-      this.pagedListResponseFactory = pagedListResponseFactory;
-    }
-
-    public Builder(PagedCallSettings<RequestT, ResponseT, PagedListResponseT> settings) {
-      super(settings);
-      this.pagedListResponseFactory = settings.pagedListResponseFactory;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT, PagedListResponseT> setRetryableCodes(
-        Set<StatusCode.Code> retryableCodes) {
-      super.setRetryableCodes(retryableCodes);
-      return this;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT, PagedListResponseT> setRetryableCodes(
-        StatusCode.Code... codes) {
-      super.setRetryableCodes(codes);
-      return this;
-    }
-
-    @Override
-    public Builder<RequestT, ResponseT, PagedListResponseT> setRetrySettings(
-        RetrySettings retrySettings) {
-      super.setRetrySettings(retrySettings);
-      return this;
-    }
-
-    public PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-        getPagedListResponseFactory() {
-      return pagedListResponseFactory;
-    }
-
-    @Override
-    public PagedCallSettings<RequestT, ResponseT, PagedListResponseT> build() {
-      return new PagedCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PagedCallable.java b/gax/src/main/java/com/google/api/gax/rpc/PagedCallable.java
deleted file mode 100644
index 5a2f47815..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PagedCallable.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.InternalApi;
-import com.google.common.base.Preconditions;
-
-/**
- * A UnaryCallable which provides page streaming functionality for unary calls.
- *
- * <p>Public for technical reasons - for advanced usage.
- */
-@InternalApi("For use by transport-specific implementations")
-public class PagedCallable<RequestT, ResponseT, PagedListResponseT>
-    extends UnaryCallable<RequestT, PagedListResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT>
-      pagedListResponseFactory;
-
-  public PagedCallable(
-      UnaryCallable<RequestT, ResponseT> callable,
-      PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT> pagedListResponseFactory) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.pagedListResponseFactory = pagedListResponseFactory;
-  }
-
-  @Override
-  public String toString() {
-    return String.format("paged(%s)", callable);
-  }
-
-  @Override
-  public ApiFuture<PagedListResponseT> futureCall(RequestT request, ApiCallContext context) {
-    ApiFuture<ResponseT> futureResponse = callable.futureCall(request, context);
-    return pagedListResponseFactory.getFuturePagedResponse(
-        callable.withDefaultCallContext(context), request, context, futureResponse);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PagedListDescriptor.java b/gax/src/main/java/com/google/api/gax/rpc/PagedListDescriptor.java
deleted file mode 100644
index ee272bb91..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PagedListDescriptor.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * An interface which provides the functionality to extract data from requests and inject data into
- * requests for the purposes of page streaming.
- *
- * <p>This class is designed to be used by generated code.
- */
-public interface PagedListDescriptor<RequestT, ResponseT, ResourceT> {
-
-  /** Delivers the empty page token. */
-  String emptyToken();
-
-  /** Injects a page token into the request. */
-  RequestT injectToken(RequestT payload, String token);
-
-  /** Injects page size setting into the request. */
-  RequestT injectPageSize(RequestT payload, int pageSize);
-
-  /** Extracts the page size setting from the request. */
-  Integer extractPageSize(RequestT payload);
-
-  /**
-   * Extracts the next token from the response. Returns the empty token if there are no more pages.
-   */
-  String extractNextToken(ResponseT payload);
-
-  /** Extracts an iterable of resources from the response. */
-  Iterable<ResourceT> extractResources(ResponseT payload);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PagedListResponseFactory.java b/gax/src/main/java/com/google/api/gax/rpc/PagedListResponseFactory.java
deleted file mode 100644
index ed8d5551d..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PagedListResponseFactory.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-
-/**
- * Interface for constructing futures which return PagedListResponse objects.
- *
- * <p>This class is designed to be used by generated code.
- */
-public interface PagedListResponseFactory<RequestT, ResponseT, PagedListResponseT> {
-
-  ApiFuture<PagedListResponseT> getFuturePagedResponse(
-      UnaryCallable<RequestT, ResponseT> callable,
-      RequestT request,
-      ApiCallContext context,
-      ApiFuture<ResponseT> futureResponse);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/PermissionDeniedException.java b/gax/src/main/java/com/google/api/gax/rpc/PermissionDeniedException.java
deleted file mode 100644
index c9e751597..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/PermissionDeniedException.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** Exception thrown when the caller does not have permission to execute the specified operation. */
-public class PermissionDeniedException extends ApiException {
-  public PermissionDeniedException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public PermissionDeniedException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public PermissionDeniedException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ProtocolBufferParsingException.java b/gax/src/main/java/com/google/api/gax/rpc/ProtocolBufferParsingException.java
deleted file mode 100644
index ce8f306a2..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ProtocolBufferParsingException.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/** Exception thrown when parsing protocol buffer message failed */
-public class ProtocolBufferParsingException extends RuntimeException {
-
-  public ProtocolBufferParsingException(String message, Throwable cause) {
-    super(message, cause);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/QueuingResponseObserver.java b/gax/src/main/java/com/google/api/gax/rpc/QueuingResponseObserver.java
deleted file mode 100644
index 36e5384bf..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/QueuingResponseObserver.java
+++ /dev/null
@@ -1,129 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.collect.Queues;
-import java.util.concurrent.BlockingQueue;
-
-/**
- * A back pressure aware bridge from a {@link ResponseObserver} to a {@link BlockingQueue}. The
- * queue size is fixed to 1 item and a close signal. The observer will manage its own flow control,
- * keeping the queue in one of 3 states:
- *
- * <ul>
- *   <li>empty: a item has been requested and we are awaiting the next item
- *   <li>1 item: an in progress stream with 1 item buffered
- *   <li>1 control signal: either a Throwable, or an EOF_MARKER which means that the stream is
- *       closed
- *   <li>1 item & 1 control signal: this is the last item of the stream
- * </ul>
- *
- * <p>The observer can also be abruptly cancelled, which cancels the underlying call and always
- * returns an EOF_MARKER.
- *
- * <p>Package-private for internal use.
- *
- * @param <V> The item type.
- */
-final class QueuingResponseObserver<V> extends StateCheckingResponseObserver<V> {
-  static final Object EOF_MARKER = new Object();
-
-  private final BlockingQueue<Object> buffer = Queues.newArrayBlockingQueue(2);
-  private StreamController controller;
-  private boolean isCancelled;
-
-  void request() {
-    controller.request(1);
-  }
-
-  Object getNext() throws InterruptedException {
-    if (isCancelled) {
-      return EOF_MARKER;
-    }
-    return buffer.take();
-  }
-
-  boolean isReady() {
-    return isCancelled || !buffer.isEmpty();
-  }
-
-  /**
-   * Cancels the underlying RPC and causes getNext to always return EOF_MARKER. This can only be
-   * called after starting the underlying call.
-   */
-  void cancel() {
-    isCancelled = true;
-    controller.cancel();
-  }
-
-  /**
-   * Before starting the RPC, disable automatic flow control and retain a reference to the
-   * controller.
-   *
-   * @param controller The controller for the stream.
-   */
-  @Override
-  protected void onStartImpl(StreamController controller) {
-    this.controller = controller;
-    controller.disableAutoInboundFlowControl();
-    controller.request(1);
-  }
-
-  /**
-   * Buffer the response. There should be at most 1 response in the buffer.
-   *
-   * @param response The received response.
-   */
-  @Override
-  protected void onResponseImpl(V response) {
-    buffer.add(response);
-  }
-
-  /**
-   * Enqueue the error to be thrown later on. The error might occur without a request so the queue
-   * might grow to 2 elements, and in that case the previous response will be consumed first.
-   *
-   * @param t The error occurred on the stream
-   */
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    buffer.add(t);
-  }
-
-  /**
-   * Enqueue a marker to notify the consumer that the stream is finished. In most situations this
-   * will cause the queue to grow to 2 elements: the requested response and an unsolicited
-   * completion marker.
-   */
-  @Override
-  protected void onCompleteImpl() {
-    buffer.add(EOF_MARKER);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RecheckingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/RecheckingCallable.java
deleted file mode 100644
index 9441223e4..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RecheckingCallable.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.retrying.RetryingExecutorWithContext;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.common.base.Preconditions;
-
-/**
- * A UnaryCallable that will keep issuing calls to an inner callable until a terminal condition is
- * met.
- *
- * <p>Note: Any request passed to this class is ignored.
- *
- * <p>Package-private for internal use.
- */
-class RecheckingCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final RetryingExecutorWithContext<ResponseT> executor;
-
-  RecheckingCallable(
-      UnaryCallable<RequestT, ResponseT> callable,
-      RetryingExecutorWithContext<ResponseT> executor) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.executor = Preconditions.checkNotNull(executor);
-  }
-
-  @Override
-  public RetryingFuture<ResponseT> futureCall(RequestT ignored, ApiCallContext inputContext) {
-    CheckingAttemptCallable<RequestT, ResponseT> checkingAttemptCallable =
-        new CheckingAttemptCallable<>(callable, inputContext);
-
-    RetryingFuture<ResponseT> retryingFuture =
-        executor.createFuture(checkingAttemptCallable, inputContext);
-    checkingAttemptCallable.setExternalFuture(retryingFuture);
-    checkingAttemptCallable.call();
-
-    return retryingFuture;
-  }
-
-  @Override
-  public String toString() {
-    return String.format("rechecking(%s)", callable);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsBuilder.java b/gax/src/main/java/com/google/api/gax/rpc/RequestParamsBuilder.java
deleted file mode 100644
index 4f234f0ce..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsBuilder.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.pathtemplate.PathTemplate;
-import com.google.common.collect.ImmutableMap;
-import java.util.Map;
-
-/**
- * This builder class builds a request params map that will be used by autogenerated implementation
- * of {@link RequestParamsExtractor}.
- */
-@BetaApi
-public class RequestParamsBuilder {
-
-  private final ImmutableMap.Builder<String, String> paramsBuilder;
-
-  private RequestParamsBuilder() {
-    this.paramsBuilder = ImmutableMap.builder();
-  }
-
-  public static RequestParamsBuilder create() {
-    return new RequestParamsBuilder();
-  }
-
-  /**
-   * Add an entry to paramsBuilder by match-and-extract field values from requests based on
-   * pre-configured path templates. This method is called repeatedly for each configured routing
-   * rule parameter, it's possible that the incoming field value from request is null or there is no
-   * matches found, we'll continue the match-and-extract process for the next routing rule parameter
-   * in such case.
-   *
-   * @param fieldValue the field value from a request
-   * @param headerKey the header key for the routing header param
-   * @param pathTemplate {@link PathTemplate} the path template used for match-and-extract
-   */
-  public void add(String fieldValue, String headerKey, PathTemplate pathTemplate) {
-    if (fieldValue == null) {
-      return;
-    }
-    Map<String, String> matchedValues = pathTemplate.match(fieldValue);
-    if (matchedValues != null && matchedValues.containsKey(headerKey)) {
-      paramsBuilder.put(headerKey, matchedValues.get(headerKey));
-    }
-  }
-
-  public Map<String, String> build() {
-    return paramsBuilder.buildKeepingLast();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsEncoder.java b/gax/src/main/java/com/google/api/gax/rpc/RequestParamsEncoder.java
deleted file mode 100644
index 19f4742eb..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsEncoder.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-
-/**
- * A request params encoder takes a {@code request} object and encodes some (or all) of its
- * parameters in a string form following specific parameter extraction and string encoding rules,
- * defined by concrete implementations of this interface.
- *
- * @param <RequestT> request message type
- */
-@InternalApi("For use by transport-specific implementations")
-public interface RequestParamsEncoder<RequestT> {
-
-  /**
-   * Encodes {@code request} message in a string.
-   *
-   * @param request request message
-   */
-  String encode(RequestT request);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsExtractor.java b/gax/src/main/java/com/google/api/gax/rpc/RequestParamsExtractor.java
deleted file mode 100644
index eb52c6e92..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RequestParamsExtractor.java
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-import java.util.Map;
-
-/**
- * A request params extractor takes a {@code request} message, extracts specific field values from
- * it, converts them in strings and returns them as key-value pairs, where a key is a request field
- * name and a value is a string representation of a field value. Nested fields should also be
- * extractable, in such case the "dot notation" can be used to represent a nested field name, for
- * example {@code "field_name.nested_field_name"}.
- *
- * <p>Implementations of this interface are expected to be autogenerated.
- *
- * @param <RequestT> request message type
- */
-@InternalApi("For use by transport-specific implementations")
-public interface RequestParamsExtractor<RequestT> {
-  /**
-   * Extracts specific fields from the {@code request} and returns them in a form of key-value
-   * pairs, where a key is a field name and a value is a field's string representation. To represent
-   * nested field names the "dot notation" can be used.
-   *
-   * @param request request message
-   */
-  Map<String, String> extract(RequestT request);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RequestUrlParamsEncoder.java b/gax/src/main/java/com/google/api/gax/rpc/RequestUrlParamsEncoder.java
deleted file mode 100644
index 6bb1da250..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RequestUrlParamsEncoder.java
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.api.core.InternalApi;
-import java.io.UnsupportedEncodingException;
-import java.net.URLDecoder;
-import java.net.URLEncoder;
-import java.util.Map;
-
-/**
- * The request params encoder, which encodes URL-encoded parameters in one URL parameters string.
- * This class expects that name-value pairs, returned from parameters extractor are already
- * URL-encoded and can perform optional validation of that, but does not encode the name-value pairs
- * themselves.
- *
- * @param <RequestT> request message type
- */
-@InternalApi("For use by transport-specific implementations")
-public class RequestUrlParamsEncoder<RequestT> implements RequestParamsEncoder<RequestT> {
-  private static final String STR_ENCODING = "UTF-8";
-
-  private final RequestParamsExtractor<RequestT> paramsExtractor;
-  private final boolean validateExtractedParameters;
-
-  /**
-   * Creates the encoder.
-   *
-   * @param paramsExtractor parameters extractor which returns already URL-encoded key-value pairs
-   * @param validateExtractedParameters {@code true} if this class should validate that the
-   *     extracted parameters are URL-encoded, {@code false} otherwise
-   */
-  public RequestUrlParamsEncoder(
-      RequestParamsExtractor<RequestT> paramsExtractor, boolean validateExtractedParameters) {
-    this.paramsExtractor = checkNotNull(paramsExtractor);
-    this.validateExtractedParameters = validateExtractedParameters;
-  }
-
-  /**
-   * Encodes the {@code request} in a form of a URL parameters string, for example {@code
-   * "param1=value+1&param2=value2%26"}. This method may optionally validate that the name-value
-   * paris are URL-encoded, but it will not perform the actual encoding of them (it will only
-   * concatenate the valid individual name-value pairs in a valid URL parameters string). This is
-   * so, because in most practical cases the name-value paris are already URL-encoded.
-   *
-   * @param request request message
-   * @throws IllegalArgumentException if is not
-   */
-  @Override
-  public String encode(RequestT request) {
-    Map<String, String> params = paramsExtractor.extract(request);
-    if (params.isEmpty()) {
-      return "";
-    }
-    StringBuilder sb = new StringBuilder();
-    for (Map.Entry<String, String> entry : params.entrySet()) {
-      if (sb.length() > 0) {
-        sb.append("&");
-      }
-      String name = entry.getKey();
-      String value = entry.getValue();
-      if (name == null) {
-        throw new IllegalArgumentException("Request parameter name cannot be null");
-      }
-
-      // Let the server decide if the value is required.
-      // Empty value is allowed.
-      if (value != null) {
-        if (!isValid(name, value)) {
-          throw new IllegalArgumentException(
-              "Invalid url-encoded request parameter name-value pair: " + name + "=" + value);
-        }
-        sb.append(name).append("=").append(value);
-      }
-    }
-
-    return sb.toString();
-  }
-
-  // Not sure if we need this at all.
-  private boolean isValid(String name, String value) {
-    try {
-      // hoping that encode/decode do not lose information in the middle
-      // (at least for practical use cases)
-      return !validateExtractedParameters
-          || name.equals(URLEncoder.encode(URLDecoder.decode(name, STR_ENCODING), STR_ENCODING))
-              && value.equals(
-                  URLEncoder.encode(URLDecoder.decode(value, STR_ENCODING), STR_ENCODING));
-    } catch (UnsupportedEncodingException e) {
-      return false;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ResourceExhaustedException.java b/gax/src/main/java/com/google/api/gax/rpc/ResourceExhaustedException.java
deleted file mode 100644
index 2561c54ce..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ResourceExhaustedException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when some resource has been exhausted, perhaps a per-user quota, or perhaps the
- * entire file system is out of space.
- */
-public class ResourceExhaustedException extends ApiException {
-  public ResourceExhaustedException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public ResourceExhaustedException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public ResourceExhaustedException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ResponseObserver.java b/gax/src/main/java/com/google/api/gax/rpc/ResponseObserver.java
deleted file mode 100644
index 77c7a82d3..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ResponseObserver.java
+++ /dev/null
@@ -1,97 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Receives notifications from server-streaming calls.
- *
- * <p>The application is responsible for implementing the {@code ResponseObserver} and passing it to
- * GAX, which then calls the observer with the messages for the application to receive them. The
- * methods might be called by different threads, but are guaranteed to happen sequentially. The
- * order of callbacks is guaranteed to be:
- *
- * <ul>
- *   <li>exactly 1 onStart
- *   <li>0 or more on Response
- *   <li>exactly 1 onError or onComplete
- * </ul>
- *
- * <p>By default, the stream uses automatic flow control, where the next response will be delivered
- * as soon as the current one is processed by onResponse. A consumer can disable automatic flow
- * control by calling {@code disableAutoInboundFlowControl()} in {@code onStart}. After this, the
- * consumer must request responses by calling {@code request()}.
- */
-public interface ResponseObserver<V> {
-
-  /**
-   * Called before the stream is started. This must be invoked synchronously on the same thread that
-   * called {@link ServerStreamingCallable#call(Object, ResponseObserver, ApiCallContext)}
-   *
-   * <p>Allows for disabling flow control and early stream termination via {@code StreamController}.
-   *
-   * @param controller The controller for the stream.
-   */
-  void onStart(StreamController controller);
-
-  /**
-   * Receives a value from the stream.
-   *
-   * <p>Can be called many times but is never called after {@link #onError(Throwable)} or {@link
-   * #onComplete()} are called.
-   *
-   * <p>Clients may may receive 0 or more onResponse callbacks.
-   *
-   * <p>If an exception is thrown by an implementation the caller will terminate the stream by
-   * calling {@link #onError(Throwable)} with the caught exception as the cause.
-   *
-   * @param response the value passed to the stream
-   */
-  void onResponse(V response);
-
-  /**
-   * Receives a terminating error from the stream.
-   *
-   * <p>May only be called once, and if called, it must be the last method called. In particular, if
-   * an exception is thrown by an implementation of {@code onError}, no further calls to any method
-   * are allowed.
-   *
-   * @param t the error occurred on the stream
-   */
-  void onError(Throwable t);
-
-  /**
-   * Receives a notification of successful stream completion.
-   *
-   * <p>May only be called once, and if called, it must be the last method called. In particular, if
-   * an exception is thrown by an implementation of {@code onComplete}, no further calls to any
-   * method are allowed.
-   */
-  void onComplete();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RetryingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/RetryingCallable.java
deleted file mode 100644
index 0a92794a2..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RetryingCallable.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.retrying.RetryingExecutorWithContext;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.common.base.Preconditions;
-
-/**
- * A UnaryCallable that will keep issuing calls to an inner callable until it succeeds or times out.
- *
- * <p>Package-private for internal use.
- */
-class RetryingCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final ApiCallContext callContextPrototype;
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final RetryingExecutorWithContext<ResponseT> executor;
-
-  RetryingCallable(
-      ApiCallContext callContextPrototype,
-      UnaryCallable<RequestT, ResponseT> callable,
-      RetryingExecutorWithContext<ResponseT> executor) {
-    this.callContextPrototype = Preconditions.checkNotNull(callContextPrototype);
-    this.callable = Preconditions.checkNotNull(callable);
-    this.executor = Preconditions.checkNotNull(executor);
-  }
-
-  @Override
-  public RetryingFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    ApiCallContext context = callContextPrototype.nullToSelf(inputContext);
-    AttemptCallable<RequestT, ResponseT> retryCallable =
-        new AttemptCallable<>(callable, request, context);
-
-    RetryingFuture<ResponseT> retryingFuture = executor.createFuture(retryCallable, inputContext);
-    retryCallable.setExternalFuture(retryingFuture);
-    retryCallable.call();
-
-    return retryingFuture;
-  }
-
-  @Override
-  public String toString() {
-    return String.format("retrying(%s)", callable);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/RetryingServerStreamingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/RetryingServerStreamingCallable.java
deleted file mode 100644
index cb7e3bb78..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/RetryingServerStreamingCallable.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.ScheduledRetryingExecutor;
-import com.google.api.gax.retrying.ServerStreamingAttemptException;
-import com.google.api.gax.retrying.StreamResumptionStrategy;
-
-/**
- * A ServerStreamingCallable that implements resumable retries.
- *
- * <p>Wraps a request, a {@link ResponseObserver} and an inner {@link ServerStreamingCallable} and
- * coordinates retries between them. When the inner callable throws an error, this class will
- * schedule retries using the configured {@link ScheduledRetryingExecutor}.
- *
- * <p>Streams can be resumed using a {@link StreamResumptionStrategy}. The {@link
- * StreamResumptionStrategy} is notified of incoming responses and is expected to track the progress
- * of the stream. Upon receiving an error, the {@link StreamResumptionStrategy} is asked to modify
- * the original request to resume the stream.
- *
- * <p>Package-private for internal use.
- */
-final class RetryingServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-
-  private final ServerStreamingCallable<RequestT, ResponseT> innerCallable;
-  private final ScheduledRetryingExecutor<Void> executor;
-  private final StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategyPrototype;
-
-  RetryingServerStreamingCallable(
-      ServerStreamingCallable<RequestT, ResponseT> innerCallable,
-      ScheduledRetryingExecutor<Void> executor,
-      StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategyPrototype) {
-    this.innerCallable = innerCallable;
-    this.executor = executor;
-    this.resumptionStrategyPrototype = resumptionStrategyPrototype;
-  }
-
-  @Override
-  public void call(
-      RequestT request,
-      final ResponseObserver<ResponseT> responseObserver,
-      ApiCallContext context) {
-
-    ServerStreamingAttemptCallable<RequestT, ResponseT> attemptCallable =
-        new ServerStreamingAttemptCallable<>(
-            innerCallable,
-            resumptionStrategyPrototype.createNew(),
-            request,
-            context,
-            responseObserver);
-
-    RetryingFuture<Void> retryingFuture = executor.createFuture(attemptCallable, context);
-    attemptCallable.setExternalFuture(retryingFuture);
-    attemptCallable.start();
-
-    // Bridge the future result back to the external responseObserver
-    ApiFutures.addCallback(
-        retryingFuture,
-        new ApiFutureCallback<Void>() {
-          @Override
-          public void onFailure(Throwable throwable) {
-            // Make sure to unwrap the underlying ApiException
-            if (throwable instanceof ServerStreamingAttemptException) {
-              throwable = throwable.getCause();
-            }
-            responseObserver.onError(throwable);
-          }
-
-          @Override
-          public void onSuccess(Void ignored) {
-            responseObserver.onComplete();
-          }
-        },
-        directExecutor());
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ServerStream.java b/gax/src/main/java/com/google/api/gax/rpc/ServerStream.java
deleted file mode 100644
index 518c68523..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ServerStream.java
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalApi;
-import java.util.Iterator;
-import javax.annotation.Nonnull;
-
-/**
- * A blocking Iterable-style wrapper around server stream responses.
- *
- * <p>This class asynchronously pulls responses from upstream via {@link
- * StreamController#request(int)} and exposes them via its Iterator. The implementation is back
- * pressure aware and uses a constant buffer of 1 item.
- *
- * <p>Please note that the stream can only be consumed once and must either be fully consumed or be
- * canceled.
- *
- * <p>Neither this class nor the iterator it returns is thread-safe.
- *
- * <p>Example usage:
- *
- * <pre>{@code
- * ServerStream<Item> stream = ...;
- *
- * for (Item item : stream) {
- *   System.out.println(item.id());
- *
- *   // Allow for early termination
- *   if (item.id().equals("needle")) {
- *     // Cancelling the stream will cause `hasNext()` to return false on the next iteration,
- *     // naturally breaking the loop.
- *     stream.cancel();
- *   }
- * }
- * }</pre>
- *
- * @param <V> The type of each response.
- */
-public class ServerStream<V> implements Iterable<V> {
-  private final QueuingResponseObserver<V> observer = new QueuingResponseObserver<>();
-  private final ServerStreamIterator<V> iterator = new ServerStreamIterator<>(observer);
-  private boolean consumed;
-
-  @InternalApi("For use by ServerStreamingCallable only.")
-  ServerStream() {}
-
-  @InternalApi("For use by ServerStreamingCallable only.")
-  ResponseObserver<V> observer() {
-    return observer;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  @Nonnull
-  public Iterator<V> iterator() {
-    if (consumed) {
-      throw new IllegalStateException("Iterator already consumed");
-    }
-    consumed = true;
-
-    return iterator;
-  }
-
-  /**
-   * Returns true if the next call to the iterator's hasNext() or next() is guaranteed to be
-   * nonblocking.
-   *
-   * @return If the call on any of the iterator's methods is guaranteed to be nonblocking.
-   */
-  public boolean isReceiveReady() {
-    return iterator.isReady();
-  }
-
-  /**
-   * Cleanly cancels a partially consumed stream. The associated iterator will return false for the
-   * hasNext() in the next iteration. This maintains the contract that an observed true from
-   * hasNext() will yield an item in next(), but afterwards will return false.
-   */
-  public void cancel() {
-    observer.cancel();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamIterator.java b/gax/src/main/java/com/google/api/gax/rpc/ServerStreamIterator.java
deleted file mode 100644
index 17a912de8..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamIterator.java
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.util.concurrent.UncheckedExecutionException;
-import java.util.Iterator;
-import java.util.NoSuchElementException;
-
-/**
- * Internal implementation of a blocking Iterator, which will coordinate with the
- * QueuingResponseObserver to fetch new items from upstream. The Iterator expects the observer to
- * request the first item, and afterwards, new items will be requested when the current ones are
- * consumed by next().
- *
- * <p>Package-private for internal use.
- *
- * @param <V> The type of items to be Iterated over.
- */
-final class ServerStreamIterator<V> implements Iterator<V> {
-  private final QueuingResponseObserver<V> observer;
-  private Object last;
-
-  ServerStreamIterator(QueuingResponseObserver<V> observer) {
-    this.observer = observer;
-  }
-
-  /**
-   * Checks if the next call to {@code hasNext()} (and {@code next()}) will block.
-   *
-   * @return true if the next call is guaranteed to be nonblocking.
-   */
-  boolean isReady() {
-    return last != null || observer.isReady();
-  }
-
-  /**
-   * Consumes the next response and asynchronously request the next response from the observer.
-   *
-   * @return The next response.
-   * @throws NoSuchElementException If the stream has been consumed or cancelled.
-   */
-  @Override
-  public V next() {
-    if (!hasNext()) {
-      throw new NoSuchElementException();
-    }
-    try {
-      observer.request();
-      @SuppressWarnings("unchecked")
-      V tmp = (V) last;
-      return tmp;
-    } finally {
-      last = null;
-    }
-  }
-
-  /**
-   * Checks if the stream has been fully consumed or cancelled. This method will block until the
-   * observer enqueues another event (response or completion event). If the observer encountered an
-   * error, this method will propagate the error and put itself into an error where it will always
-   * return the same error.
-   *
-   * @return true If iterator has more responses.
-   */
-  @Override
-  public boolean hasNext() {
-    if (last == null) {
-      try {
-        last = observer.getNext();
-      } catch (InterruptedException e) {
-        Thread.currentThread().interrupt();
-        throw new RuntimeException(e);
-      }
-    }
-    // Preserve async error while keeping the caller's stacktrace as a suppressed exception
-    if (last instanceof RuntimeException) {
-      RuntimeException runtimeException = (RuntimeException) last;
-      runtimeException.addSuppressed(new RuntimeException("Asynchronous task failed"));
-      throw runtimeException;
-    }
-
-    // This should never really happen because currently gax doesn't throw checked exceptions.
-    // Wrap checked exceptions. This will preserve both the caller's stacktrace and the async error.
-    if (last instanceof Throwable) {
-      Throwable throwable = (Throwable) last;
-      throw new UncheckedExecutionException(throwable);
-    }
-
-    return last != QueuingResponseObserver.EOF_MARKER;
-  }
-
-  /** Unsupported. */
-  @Override
-  public void remove() {
-    throw new UnsupportedOperationException();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingAttemptCallable.java b/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingAttemptCallable.java
deleted file mode 100644
index 0c71d1242..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingAttemptCallable.java
+++ /dev/null
@@ -1,391 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.ServerStreamingAttemptException;
-import com.google.api.gax.retrying.StreamResumptionStrategy;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.Callable;
-import java.util.concurrent.CancellationException;
-import javax.annotation.concurrent.GuardedBy;
-import org.threeten.bp.Duration;
-
-/**
- * A callable that generates Server Streaming attempts. At any one time, it is responsible for at
- * most a single outstanding attempt. During an attempt, it proxies all incoming message to the
- * outer {@link ResponseObserver} and the {@link StreamResumptionStrategy}. Once the attempt
- * completes, the external {@link RetryingFuture} future is notified. If the {@link RetryingFuture}
- * decides to retry the attempt, it will invoke {@link #call()}.
- *
- * <p>The lifecycle of this class is:
- *
- * <ol>
- *   <li>The caller instantiates this class.
- *   <li>The caller sets the {@link RetryingFuture} via {@link #setExternalFuture(RetryingFuture)}.
- *       The {@link RetryingFuture} will be responsible for scheduling future attempts.
- *   <li>The caller calls {@link #start()}. This notifies the outer {@link ResponseObserver} that
- *       call is about to start.
- *   <li>The outer {@link ResponseObserver} configures inbound flow control via the {@link
- *       StreamController} that it received in {@link ResponseObserver#onStart(StreamController)}.
- *   <li>The attempt call is sent via the inner/upstream {@link ServerStreamingCallable}.
- *   <li>A future representing the end state of the inner attempt is passed to the outer {@link
- *       RetryingFuture}.
- *   <li>All messages received from the inner {@link ServerStreamingCallable} are recorded by the
- *       {@link StreamResumptionStrategy}.
- *   <li>All messages received from the inner {@link ServerStreamingCallable} are forwarded to the
- *       outer {@link ResponseObserver}.
- *   <li>Upon attempt completion (either success or failure) are communicated to the outer {@link
- *       RetryingFuture}.
- *   <li>If the {@link RetryingFuture} decides to resume the RPC, it will invoke {@link #call()},
- *       which will consult the {@link StreamResumptionStrategy} for the resuming request and
- *       restart the process at step 5.
- *   <li>Once the {@link RetryingFuture} decides to stop the retry loop, it will notify the outer
- *       {@link ResponseObserver}.
- * </ol>
- *
- * <p>This class is meant to be used as middleware between an outer {@link ResponseObserver} and an
- * inner {@link ServerStreamingCallable}. As such it follows the general threading model of {@link
- * ServerStreamingCallable}s:
- *
- * <ul>
- *   <li>{@code onStart} must be called in the same thread that invoked {@code call()}
- *   <li>The outer {@link ResponseObserver} can call {@code request()} and {@code cancel()} on this
- *       class' {@link StreamController} from any thread
- *   <li>The inner callable will serialize calls to {@code onResponse()}, {@code onError()} and
- *       {@code onComplete}
- * </ul>
- *
- * <p>With this model in mind, this class only needs to synchronize access data that is shared
- * between: the outer {@link ResponseObserver} (via this class' {@link StreamController}) and the
- * inner {@link ServerStreamingCallable}: pendingRequests, cancellationCause and the current
- * innerController.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> request type
- * @param <ResponseT> response type
- */
-final class ServerStreamingAttemptCallable<RequestT, ResponseT> implements Callable<Void> {
-  private final Object lock = new Object();
-
-  private final ServerStreamingCallable<RequestT, ResponseT> innerCallable;
-  private final StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategy;
-  private final RequestT initialRequest;
-  private ApiCallContext context;
-  private final ResponseObserver<ResponseT> outerObserver;
-
-  // Start state
-  private boolean autoFlowControl = true;
-  private boolean isStarted;
-
-  // Outer state
-  @GuardedBy("lock")
-  private Throwable cancellationCause;
-
-  @GuardedBy("lock")
-  private int pendingRequests;
-
-  private RetryingFuture<Void> outerRetryingFuture;
-
-  // Internal retry state
-  private int numAttempts;
-
-  @GuardedBy("lock")
-  private StreamController innerController;
-
-  private boolean seenSuccessSinceLastError;
-  private SettableApiFuture<Void> innerAttemptFuture;
-
-  ServerStreamingAttemptCallable(
-      ServerStreamingCallable<RequestT, ResponseT> innerCallable,
-      StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategy,
-      RequestT initialRequest,
-      ApiCallContext context,
-      ResponseObserver<ResponseT> outerObserver) {
-    this.innerCallable = innerCallable;
-    this.resumptionStrategy = resumptionStrategy;
-    this.initialRequest = initialRequest;
-    this.context = context;
-    this.outerObserver = outerObserver;
-  }
-
-  /** Sets controlling {@link RetryingFuture}. Must be called be before {@link #start()}. */
-  void setExternalFuture(RetryingFuture<Void> retryingFuture) {
-    Preconditions.checkState(!isStarted, "Can't change the RetryingFuture once the call has start");
-    Preconditions.checkNotNull(retryingFuture, "RetryingFuture can't be null");
-
-    this.outerRetryingFuture = retryingFuture;
-  }
-
-  /**
-   * Starts the initial call. The call is attempted on the caller's thread. Further call attempts
-   * will be scheduled by the {@link RetryingFuture}.
-   */
-  public void start() {
-    Preconditions.checkState(!isStarted, "Already started");
-
-    // Initialize the outer observer
-    outerObserver.onStart(
-        new StreamController() {
-          @Override
-          public void disableAutoInboundFlowControl() {
-            Preconditions.checkState(
-                !isStarted, "Can't disable auto flow control once the stream is started");
-            autoFlowControl = false;
-          }
-
-          @Override
-          public void request(int count) {
-            onRequest(count);
-          }
-
-          @Override
-          public void cancel() {
-            onCancel();
-          }
-        });
-
-    if (autoFlowControl) {
-      synchronized (lock) {
-        pendingRequests = Integer.MAX_VALUE;
-      }
-    }
-    isStarted = true;
-
-    // Propagate the totalTimeout as the overall stream deadline, so long as the user
-    // has not provided a timeout via the ApiCallContext. If they have, retain it.
-    Duration totalTimeout =
-        outerRetryingFuture.getAttemptSettings().getGlobalSettings().getTotalTimeout();
-
-    if (totalTimeout != null && context != null && context.getTimeout() == null) {
-      context = context.withTimeout(totalTimeout);
-    }
-
-    // Call the inner callable
-    call();
-  }
-
-  /**
-   * Sends the actual RPC. The request being sent will first be transformed by the {@link
-   * StreamResumptionStrategy}.
-   *
-   * <p>This method expects to be called by one thread at a time. Furthermore, it expects that the
-   * current RPC finished before the next time it's called.
-   */
-  @Override
-  public Void call() {
-    Preconditions.checkState(isStarted, "Must be started first");
-
-    RequestT request =
-        (++numAttempts == 1) ? initialRequest : resumptionStrategy.getResumeRequest(initialRequest);
-
-    // Should never happen. onAttemptError will check if ResumptionStrategy can create a resume
-    // request,
-    // which the RetryingFuture/StreamResumptionStrategy should respect.
-    Preconditions.checkState(request != null, "ResumptionStrategy returned a null request.");
-
-    innerAttemptFuture = SettableApiFuture.create();
-    seenSuccessSinceLastError = false;
-
-    ApiCallContext attemptContext = context;
-
-    // Set the streamWaitTimeout to the attempt RPC Timeout, only if the context
-    // does not already have a timeout set by a user via withStreamWaitTimeout.
-    if (!outerRetryingFuture.getAttemptSettings().getRpcTimeout().isZero()
-        && attemptContext.getStreamWaitTimeout() == null) {
-      attemptContext =
-          attemptContext.withStreamWaitTimeout(
-              outerRetryingFuture.getAttemptSettings().getRpcTimeout());
-    }
-
-    attemptContext
-        .getTracer()
-        .attemptStarted(request, outerRetryingFuture.getAttemptSettings().getOverallAttemptCount());
-
-    innerCallable.call(
-        request,
-        new StateCheckingResponseObserver<ResponseT>() {
-          @Override
-          public void onStartImpl(StreamController controller) {
-            onAttemptStart(controller);
-          }
-
-          @Override
-          public void onResponseImpl(ResponseT response) {
-            onAttemptResponse(response);
-          }
-
-          @Override
-          public void onErrorImpl(Throwable t) {
-            onAttemptError(t);
-          }
-
-          @Override
-          public void onCompleteImpl() {
-            onAttemptComplete();
-          }
-        },
-        attemptContext);
-
-    outerRetryingFuture.setAttemptFuture(innerAttemptFuture);
-
-    return null;
-  }
-
-  /**
-   * Called by the inner {@link ServerStreamingCallable} when the call is about to start. This will
-   * transfer unfinished state from the previous attempt.
-   *
-   * @see ResponseObserver#onStart(StreamController)
-   */
-  private void onAttemptStart(StreamController controller) {
-    if (!autoFlowControl) {
-      controller.disableAutoInboundFlowControl();
-    }
-
-    Throwable localCancellationCause;
-    int numToRequest = 0;
-
-    synchronized (lock) {
-      innerController = controller;
-
-      localCancellationCause = this.cancellationCause;
-
-      if (!autoFlowControl) {
-        numToRequest = pendingRequests;
-      }
-    }
-
-    if (localCancellationCause != null) {
-      controller.cancel();
-    } else if (numToRequest > 0) {
-      controller.request(numToRequest);
-    }
-  }
-
-  /**
-   * Called when the outer {@link ResponseObserver} wants to prematurely cancel the stream.
-   *
-   * @see StreamController#cancel()
-   */
-  private void onCancel() {
-    StreamController localInnerController;
-
-    synchronized (lock) {
-      if (cancellationCause != null) {
-        return;
-      }
-      // NOTE: BasicRetryingFuture will replace j.u.c.CancellationExceptions with it's own,
-      // which will not have the current stacktrace, so a special wrapper has be used here.
-      cancellationCause =
-          new ServerStreamingAttemptException(
-              new CancellationException("User cancelled stream"),
-              resumptionStrategy.canResume(),
-              seenSuccessSinceLastError);
-      localInnerController = innerController;
-    }
-
-    if (localInnerController != null) {
-      localInnerController.cancel();
-    }
-  }
-
-  /**
-   * Called when the outer {@link ResponseObserver} is ready for more data.
-   *
-   * @see StreamController#request(int)
-   */
-  private void onRequest(int count) {
-    Preconditions.checkState(!autoFlowControl, "Automatic flow control is enabled");
-    Preconditions.checkArgument(count > 0, "Count must be > 0");
-
-    final StreamController localInnerController;
-
-    synchronized (lock) {
-      int maxInc = Integer.MAX_VALUE - pendingRequests;
-      count = Math.min(maxInc, count);
-
-      pendingRequests += count;
-      localInnerController = this.innerController;
-    }
-
-    // Note: there is a race condition here where the count might go to the previous attempt's
-    // StreamController after it failed. But it doesn't matter, because the controller will just
-    // ignore it and the current controller will pick it up onStart.
-    if (localInnerController != null) {
-      localInnerController.request(count);
-    }
-  }
-
-  /** Called when the inner callable has responses to deliver. */
-  private void onAttemptResponse(ResponseT message) {
-    if (!autoFlowControl) {
-      synchronized (lock) {
-        pendingRequests--;
-      }
-    }
-    // Update local state to allow for future resume.
-    seenSuccessSinceLastError = true;
-    message = resumptionStrategy.processResponse(message);
-    // Notify the outer observer.
-    outerObserver.onResponse(message);
-  }
-
-  /**
-   * Called when the current RPC fails. The error will be bubbled up to the outer {@link
-   * RetryingFuture} via the {@link #innerAttemptFuture}.
-   */
-  private void onAttemptError(Throwable throwable) {
-    Throwable localCancellationCause;
-    synchronized (lock) {
-      localCancellationCause = cancellationCause;
-    }
-
-    if (localCancellationCause != null) {
-      // Take special care to preserve the cancellation's stack trace.
-      innerAttemptFuture.setException(localCancellationCause);
-    } else {
-      // Wrap the original exception and provide more context for StreamingRetryAlgorithm.
-      innerAttemptFuture.setException(
-          new ServerStreamingAttemptException(
-              throwable, resumptionStrategy.canResume(), seenSuccessSinceLastError));
-    }
-  }
-
-  /**
-   * Called when the current RPC successfully completes. Notifies the outer {@link RetryingFuture}
-   * via {@link #innerAttemptFuture}.
-   */
-  private void onAttemptComplete() {
-    innerAttemptFuture.set(null);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallSettings.java
deleted file mode 100644
index eb9373e0c..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallSettings.java
+++ /dev/null
@@ -1,280 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.SimpleStreamResumptionStrategy;
-import com.google.api.gax.retrying.StreamResumptionStrategy;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Sets;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import org.threeten.bp.Duration;
-
-/**
- * A settings class to configure a {@link ServerStreamingCallable}.
- *
- * <p>This class includes settings that are applicable to all server streaming calls, which
- * currently just includes retries and watchdog timers.
- *
- * <p>The watchdog timer is configured via {@code idleTimeout}. The watchdog will terminate any
- * stream that has not has seen any demand (via {@link StreamController#request(int)}) in the
- * configured interval. To turn off idle checks, set the interval to {@link Duration#ZERO}.
- *
- * <p>Retry configuration allows for the stream to be restarted and resumed. It is composed of 3
- * parts: the retryable codes, the retry settings and the stream resumption strategy. The retryable
- * codes indicate which codes cause a retry to occur, the retry settings configure the retry logic
- * when the retry needs to happen, and the stream resumption strategy composes the request to resume
- * the stream. To turn off retries, set the retryable codes to the empty set.
- *
- * <p>The retry settings have slightly different semantics when compared to unary RPCs:
- *
- * <ul>
- *   <li>retry delays are reset to the initial value as soon as a response is received.
- *   <li>RPC timeouts are reset to the initial value as soon as a response is received.
- *   <li>RPC timeouts apply to the time interval between caller demanding more responses via {@link
- *       StreamController#request(int)} and the {@link ResponseObserver} receiving the message.
- *   <li>RPC timeouts are best effort and are checked once every {@link
- *       StubSettings#getStreamWatchdogCheckInterval()}.
- *   <li>Attempt counts are reset as soon as a response is received. This means that max attempts is
- *       the maximum number of failures in a row.
- *   <li>totalTimeout still applies to the entire stream.
- * </ul>
- */
-public final class ServerStreamingCallSettings<RequestT, ResponseT>
-    extends StreamingCallSettings<RequestT, ResponseT> {
-
-  @Nonnull private final Set<Code> retryableCodes;
-  @Nonnull private final RetrySettings retrySettings;
-  @Nonnull private final StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategy;
-
-  @Nonnull private final Duration idleTimeout;
-
-  private ServerStreamingCallSettings(Builder<RequestT, ResponseT> builder) {
-    this.retryableCodes = ImmutableSet.copyOf(builder.retryableCodes);
-    this.retrySettings = builder.retrySettingsBuilder.build();
-    this.resumptionStrategy = builder.resumptionStrategy;
-    this.idleTimeout = builder.idleTimeout;
-  }
-
-  /**
-   * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-   * retryableCodes do.
-   */
-  @Nonnull
-  public Set<Code> getRetryableCodes() {
-    return retryableCodes;
-  }
-
-  /**
-   * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-   * retrySettings do.
-   */
-  @Nonnull
-  public RetrySettings getRetrySettings() {
-    return retrySettings;
-  }
-
-  /**
-   * See the class documentation of {@link ServerStreamingCallSettings} and {@link
-   * StreamResumptionStrategy} for a description of what the StreamResumptionStrategy does.
-   */
-  @Nonnull
-  public StreamResumptionStrategy<RequestT, ResponseT> getResumptionStrategy() {
-    return resumptionStrategy;
-  }
-
-  /**
-   * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-   * the {@link #idleTimeout} does.
-   */
-  @Nonnull
-  public Duration getIdleTimeout() {
-    return idleTimeout;
-  }
-
-  public Builder<RequestT, ResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new Builder<>();
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("idleTimeout", idleTimeout)
-        .add("retryableCodes", retryableCodes)
-        .add("retrySettings", retrySettings)
-        .toString();
-  }
-
-  public static class Builder<RequestT, ResponseT>
-      extends StreamingCallSettings.Builder<RequestT, ResponseT> {
-    @Nonnull private Set<StatusCode.Code> retryableCodes;
-    @Nonnull private RetrySettings.Builder retrySettingsBuilder;
-    @Nonnull private StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategy;
-
-    @Nonnull private Duration idleTimeout;
-
-    /** Initialize the builder with default settings */
-    private Builder() {
-      this.retryableCodes = ImmutableSet.of();
-      this.retrySettingsBuilder = RetrySettings.newBuilder();
-      this.resumptionStrategy = new SimpleStreamResumptionStrategy<>();
-
-      this.idleTimeout = Duration.ZERO;
-    }
-
-    private Builder(ServerStreamingCallSettings<RequestT, ResponseT> settings) {
-      super(settings);
-      this.retryableCodes = settings.retryableCodes;
-      this.retrySettingsBuilder = settings.retrySettings.toBuilder();
-      this.resumptionStrategy = settings.resumptionStrategy;
-
-      this.idleTimeout = settings.idleTimeout;
-    }
-
-    /**
-     * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-     * retryableCodes do.
-     */
-    public Builder<RequestT, ResponseT> setRetryableCodes(StatusCode.Code... codes) {
-      this.setRetryableCodes(Sets.newHashSet(codes));
-      return this;
-    }
-
-    /**
-     * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-     * retryableCodes do.
-     */
-    public Builder<RequestT, ResponseT> setRetryableCodes(Set<Code> retryableCodes) {
-      Preconditions.checkNotNull(retryableCodes);
-      this.retryableCodes = Sets.newHashSet(retryableCodes);
-      return this;
-    }
-
-    @Nonnull
-    public Set<Code> getRetryableCodes() {
-      return retryableCodes;
-    }
-
-    /**
-     * Returns the underlying {@link RetrySettings.Builder}, which allows callers to augment the
-     * existing {@link RetrySettings}.
-     */
-    public RetrySettings.Builder retrySettings() {
-      return this.retrySettingsBuilder;
-    }
-
-    /**
-     * Replaces the {@link RetrySettings} for the associated {@link ServerStreamingCallable}.
-     *
-     * <p>When using the method, make sure that the {@link RetrySettings} are complete. For example,
-     * the following code will disable retries because the retry delay is not set:
-     *
-     * <pre>{@code
-     * stubSettings.setRetrySettings(
-     *   RetrySettings.newBuilder()
-     *     .setTotalTimeout(Duration.ofSeconds(10)
-     * );
-     * }</pre>
-     *
-     * @see #retrySettings()
-     */
-    public Builder<RequestT, ResponseT> setRetrySettings(@Nonnull RetrySettings retrySettings) {
-      Preconditions.checkNotNull(retrySettings);
-      this.retrySettingsBuilder = retrySettings.toBuilder();
-      return this;
-    }
-
-    @Nonnull
-    public RetrySettings getRetrySettings() {
-      return retrySettingsBuilder.build();
-    }
-
-    /** Disables retries and sets the overall timeout. */
-    public Builder<RequestT, ResponseT> setSimpleTimeoutNoRetries(@Nonnull Duration timeout) {
-      setRetryableCodes();
-      setRetrySettings(
-          RetrySettings.newBuilder()
-              .setTotalTimeout(timeout)
-              .setInitialRetryDelay(Duration.ZERO)
-              .setRetryDelayMultiplier(1)
-              .setMaxRetryDelay(Duration.ZERO)
-              .setInitialRpcTimeout(Duration.ZERO)
-              .setRpcTimeoutMultiplier(1)
-              .setMaxRpcTimeout(Duration.ZERO)
-              .setMaxAttempts(1)
-              .build());
-
-      return this;
-    }
-
-    /**
-     * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-     * StreamResumptionStrategy does.
-     */
-    public Builder<RequestT, ResponseT> setResumptionStrategy(
-        @Nonnull StreamResumptionStrategy<RequestT, ResponseT> resumptionStrategy) {
-      Preconditions.checkNotNull(resumptionStrategy);
-      this.resumptionStrategy = Preconditions.checkNotNull(resumptionStrategy);
-      return this;
-    }
-
-    @Nonnull
-    public StreamResumptionStrategy<RequestT, ResponseT> getResumptionStrategy() {
-      return resumptionStrategy;
-    }
-
-    @Nonnull
-    public Duration getIdleTimeout() {
-      return idleTimeout;
-    }
-
-    /**
-     * See the class documentation of {@link ServerStreamingCallSettings} for a description of what
-     * the {@link #idleTimeout} does. {@link Duration#ZERO} disables the watchdog.
-     */
-    public Builder<RequestT, ResponseT> setIdleTimeout(@Nonnull Duration idleTimeout) {
-      this.idleTimeout = Preconditions.checkNotNull(idleTimeout);
-      return this;
-    }
-
-    @Override
-    public ServerStreamingCallSettings<RequestT, ResponseT> build() {
-      return new ServerStreamingCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallable.java
deleted file mode 100644
index 51eed9388..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/ServerStreamingCallable.java
+++ /dev/null
@@ -1,240 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import java.util.Iterator;
-import java.util.List;
-
-/**
- * A ServerStreamingCallable is an immutable object which is capable of making RPC calls to server
- * streaming API methods. Not all transports support streaming.
- *
- * <p>It is considered advanced usage for a user to create a ServerStreamingCallable themselves.
- * This class is intended to be created by a generated client class, and configured by instances of
- * StreamingCallSettings.Builder which are exposed through the client settings class.
- */
-public abstract class ServerStreamingCallable<RequestT, ResponseT> {
-  private final FirstElementCallable<RequestT, ResponseT> firstCallable;
-  private final SpoolingCallable<RequestT, ResponseT> spoolingCallable;
-
-  protected ServerStreamingCallable() {
-    firstCallable = new FirstElementCallable<>(this);
-    spoolingCallable = new SpoolingCallable<>(this);
-  }
-
-  /**
-   * Construct a {@link UnaryCallable} that will yield the first item in the stream and cancel it.
-   * If the stream is empty, the item will be null.
-   *
-   * <p>Example usage:
-   *
-   * <pre>{@code
-   * StreamingCallable<String> streamingCallable = // ..
-   * String theResult = streamingCallable.first().call(request);
-   * ApiFuture<String> theResult = streamingCallable.first().futureCall(request);
-   * }</pre>
-   *
-   * @return The {@link UnaryCallable}.
-   */
-  public UnaryCallable<RequestT, ResponseT> first() {
-    return firstCallable;
-  }
-
-  /**
-   * Construct a {@link UnaryCallable} that will buffer the entire stream into memory before
-   * completing. If the stream is empty, then the list will be empty.
-   *
-   * <p>Example usage:
-   *
-   * <pre>{@code
-   * StreamingCallable<String> streamingCallable = // ..
-   * List<String> theResult = streamingCallable.all().call(request);
-   * ApiFuture<List<String>> theResult = streamingCallable.all().futureCall(request);
-   * }</pre>
-   *
-   * @return The {@link UnaryCallable}.
-   */
-  public UnaryCallable<RequestT, List<ResponseT>> all() {
-    return spoolingCallable;
-  }
-
-  /**
-   * Conduct a iteration server streaming call.
-   *
-   * <p>This returns a live stream that must either be fully consumed or cancelled. Example usage:
-   *
-   * <pre>{@code
-   * StreamingCallable<String> streamingCallable = // ..
-   * ServerStream stream = streamingCallable.call(request)
-   * for (String s : stream) {
-   *   if ("needle".equals(s)) {
-   *     // Cancelling the stream will cause `hasNext()` to return false on the next iteration,
-   *     // naturally breaking the loop.
-   *     stream.cancel();
-   *   }
-   * }
-   * List<String> theResult = streamingCallable.all().call(request);
-   * ApiFuture<List<String>> theResult = streamingCallable.all().futureCall(request);
-   * }</pre>
-   *
-   * @param request request
-   * @return {@link ServerStream} which is used for iterating the responses.
-   */
-  public ServerStream<ResponseT> call(RequestT request) {
-    return call(request, (ApiCallContext) null);
-  }
-
-  /**
-   * Conduct a server streaming call with the given {@link ApiCallContext}.
-   *
-   * <p>This returns a live stream that must either be fully consumed or cancelled.
-   *
-   * @param request request
-   * @param context the context
-   * @return {@link ServerStream} which is used for iterating the responses.
-   */
-  public ServerStream<ResponseT> call(RequestT request, ApiCallContext context) {
-    ServerStream<ResponseT> stream = new ServerStream<>();
-    call(request, stream.observer(), context);
-
-    return stream;
-  }
-
-  /**
-   * Conduct a server streaming call with the given {@link ApiCallContext}.
-   *
-   * @param request request
-   * @param responseObserver {@link ResponseObserver} to observe the streaming responses
-   * @param context {@link ApiCallContext} to provide context information for the RPC call.
-   */
-  public abstract void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context);
-
-  /**
-   * Conduct a server streaming call
-   *
-   * @param request request
-   * @param responseObserver {@link ResponseObserver} to observe the streaming responses
-   */
-  public void call(RequestT request, ResponseObserver<ResponseT> responseObserver) {
-    call(request, responseObserver, null);
-  }
-
-  /**
-   * Conduct a server streaming call with the given {@link ApiCallContext}.
-   *
-   * @param request request
-   * @param responseObserver {@link ApiStreamObserver} to observe the streaming responses
-   * @param context {@link ApiCallContext} to provide context information for the RPC call.
-   * @deprecated Please use the {@link ResponseObserver} variant instead.
-   */
-  @Deprecated
-  public void serverStreamingCall(
-      RequestT request,
-      final ApiStreamObserver<ResponseT> responseObserver,
-      ApiCallContext context) {
-
-    call(request, new ApiStreamObserverAdapter<>(responseObserver), context);
-  }
-
-  /**
-   * Conduct a server streaming call
-   *
-   * @param request request
-   * @param responseObserver {@link ApiStreamObserver} to observe the streaming responses
-   * @deprecated Please use the {@link ResponseObserver} variant instead.
-   */
-  @Deprecated
-  public void serverStreamingCall(RequestT request, ApiStreamObserver<ResponseT> responseObserver) {
-    serverStreamingCall(request, responseObserver, null);
-  }
-
-  /**
-   * Conduct an iteration server streaming call
-   *
-   * @param request request
-   * @param context context
-   * @return {@link Iterator} which is used for iterating the responses.
-   * @deprecated Please use call() instead.
-   */
-  @Deprecated
-  public Iterator<ResponseT> blockingServerStreamingCall(RequestT request, ApiCallContext context) {
-    return call(request, context).iterator();
-  }
-
-  /**
-   * Conduct a iteration server streaming call
-   *
-   * @param request request
-   * @return {@link Iterator} which is used for iterating the responses.
-   * @deprecated Please use call() instead.
-   */
-  @Deprecated
-  public Iterator<ResponseT> blockingServerStreamingCall(RequestT request) {
-    return blockingServerStreamingCall(request, null);
-  }
-
-  /**
-   * Returns a new {@code ServerStreamingCallable} with an {@link ApiCallContext} that is used as a
-   * default when none is supplied in individual calls.
-   *
-   * @param defaultCallContext the default {@link ApiCallContext}.
-   */
-  public ServerStreamingCallable<RequestT, ResponseT> withDefaultCallContext(
-      final ApiCallContext defaultCallContext) {
-    return new ServerStreamingCallable<RequestT, ResponseT>() {
-      // In case the next callable overrides the default behavior of first(), make sure to route
-      // the call directly to the next callable's first() implementation.
-      // The default implementation of first() instantiates a new FirstElementCallable which
-      // calls this instance's call method, bypassing the next callable's first implementation.
-      // Instead we will bypass the anonymous implementation of call() and invoke the next
-      // link's first() implementation.
-      @Override
-      public UnaryCallable<RequestT, ResponseT> first() {
-        return ServerStreamingCallable.this.first().withDefaultCallContext(defaultCallContext);
-      }
-
-      // Like, first(), make sure to respect the next callable's all() impl.
-      @Override
-      public UnaryCallable<RequestT, List<ResponseT>> all() {
-        return ServerStreamingCallable.this.all().withDefaultCallContext(defaultCallContext);
-      }
-
-      @Override
-      public void call(
-          RequestT request,
-          ResponseObserver<ResponseT> responseObserver,
-          ApiCallContext thisCallContext) {
-        ServerStreamingCallable.this.call(
-            request, responseObserver, defaultCallContext.merge(thisCallContext));
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/SpoolingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/SpoolingCallable.java
deleted file mode 100644
index fbccc520c..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/SpoolingCallable.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import java.util.List;
-
-/**
- * Wraps a {@link ServerStreamingCallable} in a buffering {@link UnaryCallable}. The {@link
- * UnaryCallable} will buffer the entire stream in memory. This is meant to be used for short
- * streams and provides interoperability with {@link UnaryCallable} middleware like {@link
- * BatchingCallable}.
- *
- * <p>Package-private for internal use.
- *
- * @param <RequestT> The type of the request.
- * @param <ResponseT> The type of an item in the stream.
- */
-class SpoolingCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, List<ResponseT>> {
-  private final ServerStreamingCallable<RequestT, ResponseT> streamingCallable;
-
-  SpoolingCallable(ServerStreamingCallable<RequestT, ResponseT> streamingCallable) {
-    this.streamingCallable = streamingCallable;
-  }
-
-  /**
-   * Starts the RPC and returns a future wrapping a list of results. If the stream is empty, the
-   * result will be an empty list. If a request is cancelled, the future will be rejected with a
-   * {@link java.util.concurrent.CancellationException}.
-   *
-   * @param request The request.
-   * @param context {@link ApiCallContext} to make the call with.
-   * @return A {@link ApiFuture} wrapping a possible first element of the stream.
-   */
-  @Override
-  public ApiFuture<List<ResponseT>> futureCall(RequestT request, ApiCallContext context) {
-    SpoolingResponseObserver<ResponseT> observer = new SpoolingResponseObserver<>();
-    streamingCallable.call(request, observer, context);
-    // NOTE: Since onStart must be called synchronously on this thread, the observer is now fully
-    // initialized and the future can be safely returned to the caller.
-    return observer.getFuture();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/SpoolingResponseObserver.java b/gax/src/main/java/com/google/api/gax/rpc/SpoolingResponseObserver.java
deleted file mode 100644
index dd1827f0b..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/SpoolingResponseObserver.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.common.collect.Lists;
-import java.util.List;
-
-/**
- * A {@link ResponseObserver} that buffers the results from a {@link ServerStreamingCallable} in an
- * {@link ApiFuture}.
- *
- * <p>Package-private for internal use.
- *
- * @param <ResponseT> The type of the element in the stream.
- */
-class SpoolingResponseObserver<ResponseT> extends StateCheckingResponseObserver<ResponseT> {
-  private final MyFuture future = new MyFuture();
-  private StreamController controller;
-  private final List<ResponseT> buffer = Lists.newArrayList();
-
-  ApiFuture<List<ResponseT>> getFuture() {
-    return future;
-  }
-
-  @Override
-  protected void onStartImpl(StreamController controller) {
-    // NOTE: the call is started before the future is exposed to the caller
-    this.controller = controller;
-  }
-
-  @Override
-  protected void onResponseImpl(ResponseT response) {
-    buffer.add(response);
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    future.setException(t);
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    future.set(buffer);
-  }
-
-  /** Simple implementation of a future that allows the receiver to cancel the underlying stream. */
-  class MyFuture extends AbstractApiFuture<List<ResponseT>> {
-    @Override
-    protected void interruptTask() {
-      SpoolingResponseObserver.this.controller.cancel();
-    }
-
-    @Override
-    protected boolean set(List<ResponseT> value) {
-      return super.set(value);
-    }
-
-    @Override
-    protected boolean setException(Throwable throwable) {
-      return super.setException(throwable);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/StateCheckingResponseObserver.java b/gax/src/main/java/com/google/api/gax/rpc/StateCheckingResponseObserver.java
deleted file mode 100644
index d787f434d..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/StateCheckingResponseObserver.java
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.base.Preconditions;
-
-/** Base implementation of {@link ResponseObserver} that performs state sanity checks. */
-public abstract class StateCheckingResponseObserver<V> implements ResponseObserver<V> {
-  private boolean isStarted;
-  private boolean isClosed;
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>This implementation simply delegates to {@link #onStartImpl(StreamController)} after
-   * ensuring consistent state.
-   */
-  public final void onStart(StreamController controller) {
-    Preconditions.checkState(!isStarted, getClass() + " is already started.");
-    isStarted = true;
-
-    onStartImpl(controller);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>This implementation simply delegates to {@link #onResponseImpl(Object)} after ensuring
-   * consistent state.
-   */
-  public final void onResponse(V response) {
-    Preconditions.checkState(!isClosed, getClass() + " received a response after being closed.");
-    onResponseImpl(response);
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>This implementation simply delegates to {@link #onCompleteImpl()} after ensuring consistent
-   * state.
-   */
-  public final void onComplete() {
-    Preconditions.checkState(!isClosed, getClass() + " tried to double close.");
-    isClosed = true;
-    onCompleteImpl();
-  }
-
-  /**
-   * {@inheritDoc}
-   *
-   * <p>This implementation simply delegates to {@link #onErrorImpl(Throwable)} after ensuring
-   * consistent state.
-   */
-  public final void onError(Throwable t) {
-    Preconditions.checkState(!isClosed, getClass() + " received error after being closed", t);
-    isClosed = true;
-    onErrorImpl(t);
-  }
-
-  /** @see #onStart(StreamController) */
-  protected abstract void onStartImpl(StreamController controller);
-
-  /** @see #onResponse(Object) */
-  protected abstract void onResponseImpl(V response);
-
-  /** @see #onErrorImpl(Throwable) */
-  protected abstract void onErrorImpl(Throwable t);
-
-  /** @see #onComplete() */
-  protected abstract void onCompleteImpl();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/StatusCode.java b/gax/src/main/java/com/google/api/gax/rpc/StatusCode.java
deleted file mode 100644
index 14163c3a8..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/StatusCode.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-
-/**
- * Transport-specific status code.
- *
- * <p>The status codes are modeled after the status codes in grpc. For more information about grpc
- * status codes, see
- * https://github.com/grpc/grpc-java/blob/master/api/src/main/java/io/grpc/Status.java
- */
-@InternalExtensionOnly
-public interface StatusCode {
-
-  enum Code {
-    OK(200),
-    CANCELLED(499),
-    UNKNOWN(500),
-    INVALID_ARGUMENT(400),
-    DEADLINE_EXCEEDED(504),
-    NOT_FOUND(404),
-    ALREADY_EXISTS(409),
-    PERMISSION_DENIED(403),
-    RESOURCE_EXHAUSTED(429),
-    FAILED_PRECONDITION(400),
-    ABORTED(409),
-    OUT_OF_RANGE(400),
-    UNIMPLEMENTED(501),
-    INTERNAL(500),
-    UNAVAILABLE(503),
-    DATA_LOSS(500),
-    UNAUTHENTICATED(401);
-
-    Code(int httpStatusCode) {
-      this.httpStatusCode = httpStatusCode;
-    }
-
-    private int httpStatusCode;
-
-    public int getHttpStatusCode() {
-      return httpStatusCode;
-    }
-  }
-
-  /** Return the code enum value. */
-  Code getCode();
-
-  /** Return the transport-specific status code value. */
-  Object getTransportCode();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/StreamController.java b/gax/src/main/java/com/google/api/gax/rpc/StreamController.java
deleted file mode 100644
index 42a09efdc..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/StreamController.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import java.util.concurrent.CancellationException;
-
-/**
- * Allows the implementer of {@link ResponseObserver} to control the flow of responses.
- *
- * <p>An instance of this class will be passed to {@link
- * ResponseObserver#onStart(StreamController)}, at which point the receiver can disable automatic
- * flow control. The receiver can also save a reference to the instance and terminate the stream
- * early using {@code cancel()}.
- */
-public interface StreamController {
-  /**
-   * Cancel the stream early.
-   *
-   * <p>This will manifest as an onError on the {@link ResponseObserver} with the cause being a
-   * {@link CancellationException}.
-   */
-  void cancel();
-
-  /**
-   * Disables automatic flow control.
-   *
-   * <p>The next response is requested immediately after the current response is processed by {@link
-   * ResponseObserver#onResponse(Object)}. If disabled, an application must make explicit calls to
-   * {@link #request} to receive messages.
-   */
-  void disableAutoInboundFlowControl();
-
-  /**
-   * Requests up to the given number of responses from the call to be delivered to {@link
-   * ResponseObserver#onResponse(Object)}. No additional messages will be delivered.
-   *
-   * <p>This method can only be called after disabling automatic flow control.
-   *
-   * <p>Message delivery is guaranteed to be sequential in the order received. In addition, the
-   * listener methods will not be accessed concurrently. While it is not guaranteed that the same
-   * thread will always be used, it is guaranteed that only a single thread will access the listener
-   * at a time.
-   *
-   * <p>If called multiple times, the number of messages able to delivered will be the sum of the
-   * calls.
-   *
-   * <p>This method is safe to call from multiple threads without external synchronizaton.
-   *
-   * @param count the requested number of messages to be delivered to the listener. Must be
-   *     non-negative.
-   */
-  void request(int count);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/StreamingCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/StreamingCallSettings.java
deleted file mode 100644
index 7f8895436..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/StreamingCallSettings.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-
-/**
- * A settings class to configure a streaming callable object for calls to a streaming API method.
- */
-@InternalExtensionOnly
-public class StreamingCallSettings<RequestT, ResponseT> {
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new Builder<>();
-  }
-
-  protected StreamingCallSettings() {}
-
-  public Builder<RequestT, ResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  public static class Builder<RequestT, ResponseT> {
-    public Builder() {}
-
-    public Builder(StreamingCallSettings<RequestT, ResponseT> settings) {}
-
-    public StreamingCallSettings<RequestT, ResponseT> build() {
-      return new StreamingCallSettings<>();
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/StubSettings.java b/gax/src/main/java/com/google/api/gax/rpc/StubSettings.java
deleted file mode 100644
index 877b03e29..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/StubSettings.java
+++ /dev/null
@@ -1,546 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.ApiFunction;
-import com.google.api.core.BetaApi;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.core.CredentialsProvider;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.core.FixedCredentialsProvider;
-import com.google.api.gax.core.FixedExecutorProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.core.NoCredentialsProvider;
-import com.google.api.gax.tracing.ApiTracerFactory;
-import com.google.api.gax.tracing.BaseApiTracerFactory;
-import com.google.auth.oauth2.QuotaProjectIdProvider;
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import java.io.IOException;
-import java.util.concurrent.Executor;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-/**
- * A base settings class to configure a client stub class.
- *
- * <p>This base class includes settings that are applicable to all services, which includes things
- * like settings for creating an executor, credentials, transport-specific settings, and identifiers
- * for http headers.
- *
- * <p>If no ExecutorProvider is set, then InstantiatingExecutorProvider will be used, which creates
- * a default executor.
- */
-public abstract class StubSettings<SettingsT extends StubSettings<SettingsT>> {
-
-  static final String QUOTA_PROJECT_ID_HEADER_KEY = "x-goog-user-project";
-
-  private final ExecutorProvider backgroundExecutorProvider;
-  private final CredentialsProvider credentialsProvider;
-  private final HeaderProvider headerProvider;
-  private final HeaderProvider internalHeaderProvider;
-  private final TransportChannelProvider transportChannelProvider;
-  private final ApiClock clock;
-  private final String endpoint;
-  private final String mtlsEndpoint;
-  private final String quotaProjectId;
-  @Nullable private final WatchdogProvider streamWatchdogProvider;
-  @Nonnull private final Duration streamWatchdogCheckInterval;
-  @Nonnull private final ApiTracerFactory tracerFactory;
-  // Track if deprecated setExecutorProvider is called
-  private boolean deprecatedExecutorProviderSet;
-
-  /**
-   * Indicate when creating transport whether it is allowed to use mTLS endpoint instead of the
-   * default endpoint. Only the endpoint set by client libraries is allowed. User provided endpoint
-   * should always be used as it is. Client libraries can set it via the {@link
-   * Builder#setSwitchToMtlsEndpointAllowed} method.
-   */
-  private final boolean switchToMtlsEndpointAllowed;
-
-  /** Constructs an instance of StubSettings. */
-  protected StubSettings(Builder builder) {
-    this.backgroundExecutorProvider = builder.backgroundExecutorProvider;
-    this.transportChannelProvider = builder.transportChannelProvider;
-    this.credentialsProvider = builder.credentialsProvider;
-    this.headerProvider = builder.headerProvider;
-    this.internalHeaderProvider = builder.internalHeaderProvider;
-    this.clock = builder.clock;
-    this.endpoint = builder.endpoint;
-    this.mtlsEndpoint = builder.mtlsEndpoint;
-    this.switchToMtlsEndpointAllowed = builder.switchToMtlsEndpointAllowed;
-    this.quotaProjectId = builder.quotaProjectId;
-    this.streamWatchdogProvider = builder.streamWatchdogProvider;
-    this.streamWatchdogCheckInterval = builder.streamWatchdogCheckInterval;
-    this.tracerFactory = builder.tracerFactory;
-    this.deprecatedExecutorProviderSet = builder.deprecatedExecutorProviderSet;
-  }
-
-  /** @deprecated Please use {@link #getBackgroundExecutorProvider()}. */
-  @Deprecated
-  public final ExecutorProvider getExecutorProvider() {
-    return deprecatedExecutorProviderSet ? backgroundExecutorProvider : null;
-  }
-
-  public final ExecutorProvider getBackgroundExecutorProvider() {
-    return backgroundExecutorProvider;
-  }
-
-  public final TransportChannelProvider getTransportChannelProvider() {
-    return transportChannelProvider;
-  }
-
-  public final CredentialsProvider getCredentialsProvider() {
-    return credentialsProvider;
-  }
-
-  public final HeaderProvider getHeaderProvider() {
-    return headerProvider;
-  }
-
-  protected final HeaderProvider getInternalHeaderProvider() {
-    return internalHeaderProvider;
-  }
-
-  public final ApiClock getClock() {
-    return clock;
-  }
-
-  public final String getEndpoint() {
-    return endpoint;
-  }
-
-  public final String getMtlsEndpoint() {
-    return mtlsEndpoint;
-  }
-
-  /** Limit the visibility to this package only since only this package needs it. */
-  final boolean getSwitchToMtlsEndpointAllowed() {
-    return switchToMtlsEndpointAllowed;
-  }
-
-  public final String getQuotaProjectId() {
-    return quotaProjectId;
-  }
-
-  @Nullable
-  public final WatchdogProvider getStreamWatchdogProvider() {
-    return streamWatchdogProvider;
-  }
-
-  @Nonnull
-  public final Duration getStreamWatchdogCheckInterval() {
-    return streamWatchdogCheckInterval;
-  }
-
-  /**
-   * Gets the configured {@link ApiTracerFactory} that will be used to generate traces for
-   * operations.
-   */
-  @BetaApi("The surface for tracing is not stable yet and may change in the future.")
-  @Nonnull
-  public ApiTracerFactory getTracerFactory() {
-    return tracerFactory;
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("backgroundExecutorProvider", backgroundExecutorProvider)
-        .add("transportChannelProvider", transportChannelProvider)
-        .add("credentialsProvider", credentialsProvider)
-        .add("headerProvider", headerProvider)
-        .add("internalHeaderProvider", internalHeaderProvider)
-        .add("clock", clock)
-        .add("endpoint", endpoint)
-        .add("mtlsEndpoint", mtlsEndpoint)
-        .add("switchToMtlsEndpointAllowed", switchToMtlsEndpointAllowed)
-        .add("quotaProjectId", quotaProjectId)
-        .add("streamWatchdogProvider", streamWatchdogProvider)
-        .add("streamWatchdogCheckInterval", streamWatchdogCheckInterval)
-        .add("tracerFactory", tracerFactory)
-        .toString();
-  }
-
-  public abstract StubSettings.Builder toBuilder();
-
-  public abstract static class Builder<
-      SettingsT extends StubSettings<SettingsT>, B extends Builder<SettingsT, B>> {
-
-    private ExecutorProvider backgroundExecutorProvider;
-    private CredentialsProvider credentialsProvider;
-    private HeaderProvider headerProvider;
-    private HeaderProvider internalHeaderProvider;
-    private TransportChannelProvider transportChannelProvider;
-    private ApiClock clock;
-    private String endpoint;
-    private String mtlsEndpoint;
-    private String quotaProjectId;
-    @Nullable private WatchdogProvider streamWatchdogProvider;
-    @Nonnull private Duration streamWatchdogCheckInterval;
-    @Nonnull private ApiTracerFactory tracerFactory;
-    private boolean deprecatedExecutorProviderSet;
-
-    /**
-     * Indicate when creating transport whether it is allowed to use mTLS endpoint instead of the
-     * default endpoint. Only the endpoint set by client libraries is allowed. User provided
-     * endpoint should always be used as it is. Client libraries can set it via the {@link
-     * Builder#setSwitchToMtlsEndpointAllowed} method.
-     */
-    private boolean switchToMtlsEndpointAllowed = false;
-
-    /** Create a builder from a StubSettings object. */
-    protected Builder(StubSettings settings) {
-      this.backgroundExecutorProvider = settings.backgroundExecutorProvider;
-      this.transportChannelProvider = settings.transportChannelProvider;
-      this.credentialsProvider = settings.credentialsProvider;
-      this.headerProvider = settings.headerProvider;
-      this.internalHeaderProvider = settings.internalHeaderProvider;
-      this.clock = settings.clock;
-      this.endpoint = settings.endpoint;
-      this.mtlsEndpoint = settings.mtlsEndpoint;
-      this.switchToMtlsEndpointAllowed = settings.switchToMtlsEndpointAllowed;
-      this.quotaProjectId = settings.quotaProjectId;
-      this.streamWatchdogProvider = settings.streamWatchdogProvider;
-      this.streamWatchdogCheckInterval = settings.streamWatchdogCheckInterval;
-      this.tracerFactory = settings.tracerFactory;
-      this.deprecatedExecutorProviderSet = settings.deprecatedExecutorProviderSet;
-    }
-
-    /** Get Quota Project ID from Client Context * */
-    private static String getQuotaProjectIdFromClientContext(ClientContext clientContext) {
-      if (clientContext.getQuotaProjectId() != null) {
-        return clientContext.getQuotaProjectId();
-      }
-      if (clientContext.getCredentials() instanceof QuotaProjectIdProvider) {
-        return ((QuotaProjectIdProvider) clientContext.getCredentials()).getQuotaProjectId();
-      }
-      if (clientContext.getHeaders().containsKey(QUOTA_PROJECT_ID_HEADER_KEY)) {
-        return clientContext.getHeaders().get(QUOTA_PROJECT_ID_HEADER_KEY);
-      }
-      if (clientContext.getInternalHeaders().containsKey(QUOTA_PROJECT_ID_HEADER_KEY)) {
-        return clientContext.getInternalHeaders().get(QUOTA_PROJECT_ID_HEADER_KEY);
-      }
-      return null;
-    }
-
-    protected Builder(ClientContext clientContext) {
-      if (clientContext == null) {
-        this.backgroundExecutorProvider = InstantiatingExecutorProvider.newBuilder().build();
-        this.transportChannelProvider = null;
-        this.credentialsProvider = NoCredentialsProvider.create();
-        this.headerProvider = new NoHeaderProvider();
-        this.internalHeaderProvider = new NoHeaderProvider();
-        this.clock = NanoClock.getDefaultClock();
-        this.endpoint = null;
-        this.mtlsEndpoint = null;
-        this.quotaProjectId = null;
-        this.streamWatchdogProvider = InstantiatingWatchdogProvider.create();
-        this.streamWatchdogCheckInterval = Duration.ofSeconds(10);
-        this.tracerFactory = BaseApiTracerFactory.getInstance();
-        this.deprecatedExecutorProviderSet = false;
-      } else {
-        ExecutorProvider fixedExecutorProvider =
-            FixedExecutorProvider.create(clientContext.getExecutor());
-        this.deprecatedExecutorProviderSet = true;
-        this.backgroundExecutorProvider = fixedExecutorProvider;
-        this.transportChannelProvider =
-            FixedTransportChannelProvider.create(clientContext.getTransportChannel());
-        this.credentialsProvider = FixedCredentialsProvider.create(clientContext.getCredentials());
-        this.headerProvider = FixedHeaderProvider.create(clientContext.getHeaders());
-        this.internalHeaderProvider =
-            FixedHeaderProvider.create(clientContext.getInternalHeaders());
-        this.clock = clientContext.getClock();
-        this.endpoint = clientContext.getEndpoint();
-        if (this.endpoint != null) {
-          this.mtlsEndpoint = this.endpoint.replace("googleapis.com", "mtls.googleapis.com");
-        }
-        this.streamWatchdogProvider =
-            FixedWatchdogProvider.create(clientContext.getStreamWatchdog());
-        this.streamWatchdogCheckInterval = clientContext.getStreamWatchdogCheckInterval();
-        this.tracerFactory = clientContext.getTracerFactory();
-        this.quotaProjectId = getQuotaProjectIdFromClientContext(clientContext);
-      }
-    }
-
-    protected Builder() {
-      this((ClientContext) null);
-    }
-
-    @SuppressWarnings("unchecked")
-    protected B self() {
-      return (B) this;
-    }
-
-    /**
-     * Sets the ExecutorProvider to use for getting the executor to use for running asynchronous API
-     * call logic (such as retries and long-running operations), and also to pass to the transport
-     * settings if an executor is needed for the transport and it doesn't have its own executor
-     * provider.
-     *
-     * @deprecated Please use {@link #setBackgroundExecutorProvider(ExecutorProvider)} for setting
-     *     executor to use for running scheduled API call logic. To set executor for {@link
-     *     TransportChannelProvider}, please use {@link
-     *     TransportChannelProvider#withExecutor(Executor)} instead.
-     */
-    @Deprecated
-    public B setExecutorProvider(ExecutorProvider executorProvider) {
-      // For backward compatibility, this will set backgroundExecutorProvider and mark
-      // deprecatedExecutorProviderSet to true. In ClientContext#create(), if
-      // TransportChannelProvider doesn't have an executor, and deprecatedExecutorProviderSet is
-      // true, backgroundExecutorProvider will be used as TransportChannelProvider's executor.
-      // After this method is deprecated, TransportChannelProvider's executor can only be set with
-      // TransportChannelProvider#withExecutor.
-      this.deprecatedExecutorProviderSet = true;
-      this.backgroundExecutorProvider = executorProvider;
-      return self();
-    }
-
-    /**
-     * Sets the executor to use for running scheduled API call logic (such as retries and
-     * long-running operations).
-     */
-    public B setBackgroundExecutorProvider(ExecutorProvider backgroundExecutorProvider) {
-      this.backgroundExecutorProvider = backgroundExecutorProvider;
-      return self();
-    }
-
-    /** Sets the CredentialsProvider to use for getting the credentials to make calls with. */
-    public B setCredentialsProvider(CredentialsProvider credentialsProvider) {
-      this.credentialsProvider = Preconditions.checkNotNull(credentialsProvider);
-      return self();
-    }
-
-    /**
-     * Sets the HeaderProvider for getting custom static headers for http requests. The header
-     * provider will be called during client construction only once. The headers returned by the
-     * provider will be cached and supplied as is for each request issued by the constructed client.
-     * Some reserved headers can be overridden (e.g. Content-Type) or merged with the default value
-     * (e.g. User-Agent) by the underlying transport layer.
-     */
-    public B setHeaderProvider(HeaderProvider headerProvider) {
-      this.headerProvider = headerProvider;
-      if (this.quotaProjectId == null
-          && headerProvider.getHeaders().containsKey(QUOTA_PROJECT_ID_HEADER_KEY)) {
-        this.quotaProjectId = headerProvider.getHeaders().get(QUOTA_PROJECT_ID_HEADER_KEY);
-      }
-      return self();
-    }
-
-    /**
-     * Sets the HeaderProvider for getting internal (library-defined) static headers for http
-     * requests. The header provider will be called during client construction only once. The
-     * headers returned by the provider will be cached and supplied as is for each request issued by
-     * the constructed client. Some reserved headers can be overridden (e.g. Content-Type) or merged
-     * with the default value (e.g. User-Agent) by the underlying transport layer.
-     */
-    protected B setInternalHeaderProvider(HeaderProvider internalHeaderProvider) {
-      this.internalHeaderProvider = internalHeaderProvider;
-      if (this.quotaProjectId == null
-          && internalHeaderProvider.getHeaders().containsKey(QUOTA_PROJECT_ID_HEADER_KEY)) {
-        this.quotaProjectId = internalHeaderProvider.getHeaders().get(QUOTA_PROJECT_ID_HEADER_KEY);
-      }
-      return self();
-    }
-
-    /**
-     * Sets the TransportProvider to use for getting the transport-specific context to make calls
-     * with.
-     */
-    public B setTransportChannelProvider(TransportChannelProvider transportChannelProvider) {
-      this.transportChannelProvider = transportChannelProvider;
-      return self();
-    }
-
-    /**
-     * Sets the {@link WatchdogProvider} to use for streaming RPC.
-     *
-     * <p>This will default to a {@link InstantiatingWatchdogProvider} if it is not set.
-     */
-    public B setStreamWatchdogProvider(@Nullable WatchdogProvider streamWatchdogProvider) {
-      this.streamWatchdogProvider = streamWatchdogProvider;
-      return self();
-    }
-
-    /**
-     * Sets the clock to use for retry logic.
-     *
-     * <p>This will default to a system clock if it is not set.
-     */
-    public B setClock(ApiClock clock) {
-      this.clock = clock;
-      return self();
-    }
-
-    public B setEndpoint(String endpoint) {
-      this.endpoint = endpoint;
-      this.switchToMtlsEndpointAllowed = false;
-      if (this.endpoint != null && this.mtlsEndpoint == null) {
-        this.mtlsEndpoint = this.endpoint.replace("googleapis.com", "mtls.googleapis.com");
-      }
-      return self();
-    }
-
-    protected B setSwitchToMtlsEndpointAllowed(boolean switchToMtlsEndpointAllowed) {
-      this.switchToMtlsEndpointAllowed = switchToMtlsEndpointAllowed;
-      return self();
-    }
-
-    public B setMtlsEndpoint(String mtlsEndpoint) {
-      this.mtlsEndpoint = mtlsEndpoint;
-      return self();
-    }
-
-    public B setQuotaProjectId(String quotaProjectId) {
-      this.quotaProjectId = quotaProjectId;
-      return self();
-    }
-
-    /**
-     * Sets how often the {@link Watchdog} will check ongoing streaming RPCs. Defaults to 10 secs.
-     * Use {@link Duration#ZERO} to disable.
-     */
-    public B setStreamWatchdogCheckInterval(@Nonnull Duration checkInterval) {
-      Preconditions.checkNotNull(checkInterval);
-      this.streamWatchdogCheckInterval = checkInterval;
-      return self();
-    }
-
-    /**
-     * Configures the {@link ApiTracerFactory} that will be used to generate traces.
-     *
-     * @param tracerFactory an instance of {@link ApiTracerFactory} to set.
-     */
-    @BetaApi("The surface for tracing is not stable yet and may change in the future.")
-    public B setTracerFactory(@Nonnull ApiTracerFactory tracerFactory) {
-      Preconditions.checkNotNull(tracerFactory);
-      this.tracerFactory = tracerFactory;
-      return self();
-    }
-
-    /** @deprecated Please use {@link #getBackgroundExecutorProvider()}. */
-    @Deprecated
-    public ExecutorProvider getExecutorProvider() {
-      return deprecatedExecutorProviderSet ? backgroundExecutorProvider : null;
-    }
-
-    /** Gets the ExecutorProvider that was previously set on this Builder. */
-    public ExecutorProvider getBackgroundExecutorProvider() {
-      return backgroundExecutorProvider;
-    }
-
-    /** Gets the TransportProvider that was previously set on this Builder. */
-    public TransportChannelProvider getTransportChannelProvider() {
-      return transportChannelProvider;
-    }
-
-    /** Gets the CredentialsProvider that was previously set on this Builder. */
-    public CredentialsProvider getCredentialsProvider() {
-      return credentialsProvider;
-    }
-
-    /** Gets the custom HeaderProvider that was previously set on this Builder. */
-    public HeaderProvider getHeaderProvider() {
-      return headerProvider;
-    }
-
-    /** Gets the internal HeaderProvider that was previously set on this Builder. */
-    protected HeaderProvider getInternalHeaderProvider() {
-      return internalHeaderProvider;
-    }
-
-    /** Gets the {@link WatchdogProvider }that was previously set on this Builder. */
-    @Nullable
-    public WatchdogProvider getStreamWatchdogProvider() {
-      return streamWatchdogProvider;
-    }
-
-    /** Gets the ApiClock that was previously set on this Builder. */
-    public ApiClock getClock() {
-      return clock;
-    }
-
-    public String getEndpoint() {
-      return endpoint;
-    }
-
-    public String getMtlsEndpoint() {
-      return mtlsEndpoint;
-    }
-
-    /** Gets the QuotaProjectId that was previously set on this Builder. */
-    public String getQuotaProjectId() {
-      return quotaProjectId;
-    }
-
-    @Nonnull
-    public Duration getStreamWatchdogCheckInterval() {
-      return streamWatchdogCheckInterval;
-    }
-
-    @BetaApi("The surface for tracing is not stable yet and may change in the future.")
-    @Nonnull
-    public ApiTracerFactory getTracerFactory() {
-      return tracerFactory;
-    }
-
-    /** Applies the given settings updater function to the given method settings builders. */
-    protected static void applyToAllUnaryMethods(
-        Iterable<UnaryCallSettings.Builder<?, ?>> methodSettingsBuilders,
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
-      for (UnaryCallSettings.Builder<?, ?> settingsBuilder : methodSettingsBuilders) {
-        settingsUpdater.apply(settingsBuilder);
-      }
-    }
-
-    public abstract <B extends StubSettings<B>> StubSettings<B> build() throws IOException;
-
-    @Override
-    public String toString() {
-      return MoreObjects.toStringHelper(this)
-          .add("backgroundExecutorProvider", backgroundExecutorProvider)
-          .add("transportChannelProvider", transportChannelProvider)
-          .add("credentialsProvider", credentialsProvider)
-          .add("headerProvider", headerProvider)
-          .add("internalHeaderProvider", internalHeaderProvider)
-          .add("clock", clock)
-          .add("endpoint", endpoint)
-          .add("mtlsEndpoint", mtlsEndpoint)
-          .add("switchToMtlsEndpointAllowed", switchToMtlsEndpointAllowed)
-          .add("quotaProjectId", quotaProjectId)
-          .add("streamWatchdogProvider", streamWatchdogProvider)
-          .add("streamWatchdogCheckInterval", streamWatchdogCheckInterval)
-          .add("tracerFactory", tracerFactory)
-          .toString();
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/TranslatingUnaryCallable.java b/gax/src/main/java/com/google/api/gax/rpc/TranslatingUnaryCallable.java
deleted file mode 100644
index 8cc151238..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/TranslatingUnaryCallable.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-
-/**
- * A UnaryCallable that translates request types and response types using the given transformers.
- */
-public class TranslatingUnaryCallable<InnerRequestT, InnerResponseT, OuterRequestT, OuterResponseT>
-    extends UnaryCallable<OuterRequestT, OuterResponseT> {
-  private final UnaryCallable<InnerRequestT, InnerResponseT> innerUnaryCallable;
-  private final ApiFunction<OuterRequestT, InnerRequestT> requestTransformer;
-  private final ApiFunction<InnerResponseT, OuterResponseT> responseTransformer;
-
-  private TranslatingUnaryCallable(
-      UnaryCallable<InnerRequestT, InnerResponseT> innerUnaryCallable,
-      ApiFunction<OuterRequestT, InnerRequestT> requestTransformer,
-      ApiFunction<InnerResponseT, OuterResponseT> responseTransformer) {
-    this.innerUnaryCallable = innerUnaryCallable;
-    this.requestTransformer = requestTransformer;
-    this.responseTransformer = responseTransformer;
-  }
-
-  @Override
-  public ApiFuture<OuterResponseT> futureCall(OuterRequestT request, ApiCallContext context) {
-    InnerRequestT innerRequest = requestTransformer.apply(request);
-    return ApiFutures.transform(
-        innerUnaryCallable.futureCall(innerRequest, context),
-        responseTransformer,
-        directExecutor());
-  }
-
-  public static <InnerRequestT, InnerResponseT, OuterRequestT, OuterResponseT>
-      TranslatingUnaryCallable<InnerRequestT, InnerResponseT, OuterRequestT, OuterResponseT> create(
-          UnaryCallable<InnerRequestT, InnerResponseT> innerUnaryCallable,
-          ApiFunction<OuterRequestT, InnerRequestT> requestTransformer,
-          ApiFunction<InnerResponseT, OuterResponseT> responseTransformer) {
-    return new TranslatingUnaryCallable<>(
-        innerUnaryCallable, requestTransformer, responseTransformer);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/TransportChannel.java b/gax/src/main/java/com/google/api/gax/rpc/TransportChannel.java
deleted file mode 100644
index d54352e9b..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/TransportChannel.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.core.BackgroundResource;
-
-/** Class whose instances can issue RPCs on a particular transport. */
-@InternalExtensionOnly
-public interface TransportChannel extends BackgroundResource {
-
-  /**
-   * The name of the transport.
-   *
-   * <p>This string can be used for identifying transports for switching logic.
-   */
-  String getTransportName();
-
-  /**
-   * Returns an empty {@link ApiCallContext} that is compatible with this {@code TransportChannel}.
-   */
-  ApiCallContext getEmptyCallContext();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/TransportChannelProvider.java b/gax/src/main/java/com/google/api/gax/rpc/TransportChannelProvider.java
deleted file mode 100644
index b2acd458f..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/TransportChannelProvider.java
+++ /dev/null
@@ -1,145 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalExtensionOnly;
-import com.google.auth.Credentials;
-import java.io.IOException;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-
-/**
- * Provides an interface to either build a TransportChannel or provide a fixed TransportChannel that
- * will be used to make calls to a service.
- *
- * <p>Implementations of {@link TransportChannelProvider} may choose to create a new {@link
- * TransportChannel} for each call to {@link #getTransportChannel}, or may return a fixed {@link
- * TransportChannel} instance.
- *
- * <p>Callers should use the following pattern to get a channel:
- *
- * <pre><code>
- * TransportChannelProvider transportChannelProvider = ...;
- * if (transportChannelProvider.needsHeaders()) {
- *   transportChannelProvider = transportChannelProvider.withHeaders(headers);
- * }
- * // optional: set executor for TransportChannel
- * transportChannelProvider.withExecutor(executor);
- * TransportChannel transportChannel = transportChannelProvider.getTransportChannel();
- * </code></pre>
- */
-@InternalExtensionOnly
-public interface TransportChannelProvider {
-  /** Indicates whether the TransportChannel should be closed by the containing client class. */
-  boolean shouldAutoClose();
-
-  /**
-   * True if the TransportProvider needs an executor.
-   *
-   * @deprecated Channel providers will have default executors if they need one.
-   */
-  @Deprecated
-  boolean needsExecutor();
-
-  /** Sets the executor to use when constructing a new {@link TransportChannel}. */
-  TransportChannelProvider withExecutor(Executor executor);
-
-  /** @deprecated Please use {@link #withExecutor(Executor)}. */
-  @Deprecated
-  TransportChannelProvider withExecutor(ScheduledExecutorService executor);
-
-  /** True if the TransportProvider has no headers provided. */
-  boolean needsHeaders();
-
-  /**
-   * Sets the headers to use when constructing a new {@link TransportChannel}.
-   *
-   * <p>This method should only be called if {@link #needsHeaders()} returns true.
-   */
-  TransportChannelProvider withHeaders(Map<String, String> headers);
-
-  /** True if the TransportProvider has no endpoint set. */
-  boolean needsEndpoint();
-
-  /**
-   * Sets the endpoint to use when constructing a new {@link TransportChannel}.
-   *
-   * <p>This method should only be called if {@link #needsEndpoint()} returns true.
-   */
-  TransportChannelProvider withEndpoint(String endpoint);
-
-  /**
-   * Reports whether this provider allows pool size customization.
-   *
-   * @deprecated Pool settings should be configured on the builder of the specific implementation.
-   */
-  @Deprecated
-  boolean acceptsPoolSize();
-
-  /**
-   * Number of underlying transport channels to open. Calls will be load balanced across them.
-   *
-   * @deprecated Pool settings should be configured on the builder of the specific implementation.
-   */
-  @Deprecated
-  TransportChannelProvider withPoolSize(int size);
-
-  /** True if credentials are needed before channel creation. */
-  @BetaApi("The surface to customize credentials is not stable yet and may change in the future.")
-  boolean needsCredentials();
-
-  /** Sets the credentials that will be applied before channel creation. */
-  @BetaApi("The surface to customize credentials is not stable yet and may change in the future.")
-  TransportChannelProvider withCredentials(Credentials credentials);
-
-  /**
-   * Provides a Transport, which could either be a new instance for every call, or the same
-   * instance, depending on the implementation.
-   *
-   * <p>If {@link #needsExecutor()} is true, then {@link #withExecutor(Executor)} needs to be called
-   * first to provide an executor.
-   *
-   * <p>If {@link #needsHeaders()} is true, then {@link #withHeaders(Map)} needs to be called first
-   * to provide headers.
-   *
-   * <p>if {@link #needsEndpoint()} is true, then {@link #withEndpoint(String)} needs to be called
-   * first to provide an endpoint.
-   */
-  TransportChannel getTransportChannel() throws IOException;
-
-  /**
-   * The name of the transport.
-   *
-   * <p>This string can be used for identifying transports for switching logic.
-   */
-  String getTransportName();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnaryCallSettings.java b/gax/src/main/java/com/google/api/gax/rpc/UnaryCallSettings.java
deleted file mode 100644
index c8f281144..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnaryCallSettings.java
+++ /dev/null
@@ -1,240 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.InternalExtensionOnly;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Sets;
-import java.util.Set;
-import org.threeten.bp.Duration;
-
-/**
- * A base settings class to configure a UnaryCallable. An instance of UnaryCallSettings is not
- * sufficient on its own to construct a UnaryCallable; a concrete derived type is necessary.
- *
- * <p>This base class includes settings that are applicable to all calls, which currently is just
- * retry settings.
- *
- * <p>Retry configuration is composed of two parts: the retryable codes, and the retry settings. The
- * retryable codes indicate which codes cause a retry to occur, and the retry settings configure the
- * retry logic when the retry needs to happen. To turn off retries, set the retryable codes to the
- * empty set.
- *
- * <p>UnaryCallSettings contains a concrete builder class, {@link UnaryCallSettings.Builder}. This
- * builder class cannot be used to create an instance of UnaryCallSettings, because
- * UnaryCallSettings is an abstract class.
- */
-@InternalExtensionOnly
-public class UnaryCallSettings<RequestT, ResponseT> {
-
-  private final ImmutableSet<StatusCode.Code> retryableCodes;
-  private final RetrySettings retrySettings;
-
-  /**
-   * See the class documentation of {@link UnaryCallSettings} for a description of what retryable
-   * codes do.
-   */
-  public final Set<StatusCode.Code> getRetryableCodes() {
-    return retryableCodes;
-  }
-
-  /**
-   * See the class documentation of {@link UnaryCallSettings} for a description of what retry
-   * settings do.
-   */
-  public final RetrySettings getRetrySettings() {
-    return retrySettings;
-  }
-
-  public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newUnaryCallSettingsBuilder() {
-    return new Builder<>();
-  }
-
-  public Builder<RequestT, ResponseT> toBuilder() {
-    return new Builder<>(this);
-  }
-
-  protected UnaryCallSettings(Builder<RequestT, ResponseT> builder) {
-    this.retryableCodes = ImmutableSet.copyOf(builder.retryableCodes);
-    this.retrySettings = builder.retrySettingsBuilder.build();
-  }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("retryableCodes", retryableCodes)
-        .add("retrySettings", retrySettings)
-        .toString();
-  }
-
-  @Override
-  public int hashCode() {
-    int prime = 43;
-    int result = prime + ((retrySettings == null) ? 0 : retrySettings.hashCode());
-    result = prime * result + ((retryableCodes == null) ? 0 : retryableCodes.hashCode());
-    return result;
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    } else if (obj == null) {
-      return false;
-    } else if (getClass() != obj.getClass()) {
-      return false;
-    }
-
-    UnaryCallSettings<?, ?> other = (UnaryCallSettings<?, ?>) obj;
-    if (!retrySettings.equals(other.retrySettings)) {
-      return false;
-    } else if (!retryableCodes.equals(other.retryableCodes)) {
-      return false;
-    }
-    return true;
-  }
-
-  /**
-   * A base builder class for {@link UnaryCallSettings}. This class should not be used to create an
-   * instance of the base class UnaryCallSettings. See the class documentation of {@link
-   * UnaryCallSettings} for a description of the different values that can be set, and for a
-   * description of when this builder may be used. Builders for concrete derived classes can be used
-   * to create instances of those classes.
-   */
-  public static class Builder<RequestT, ResponseT> {
-
-    private Set<StatusCode.Code> retryableCodes;
-    private RetrySettings.Builder retrySettingsBuilder;
-
-    protected Builder() {
-      retryableCodes = Sets.newHashSet();
-      retrySettingsBuilder = RetrySettings.newBuilder();
-    }
-
-    protected Builder(UnaryCallSettings<RequestT, ResponseT> unaryCallSettings) {
-      setRetryableCodes(unaryCallSettings.retryableCodes);
-      setRetrySettings(unaryCallSettings.getRetrySettings());
-    }
-
-    /**
-     * See the class documentation of {@link UnaryCallSettings} for a description of what retryable
-     * codes do.
-     */
-    public UnaryCallSettings.Builder<RequestT, ResponseT> setRetryableCodes(
-        Set<StatusCode.Code> retryableCodes) {
-      this.retryableCodes = Sets.newHashSet(retryableCodes);
-      return this;
-    }
-
-    /**
-     * See the class documentation of {@link UnaryCallSettings} for a description of what retryable
-     * codes do.
-     */
-    public UnaryCallSettings.Builder<RequestT, ResponseT> setRetryableCodes(
-        StatusCode.Code... codes) {
-      this.setRetryableCodes(Sets.newHashSet(codes));
-      return this;
-    }
-
-    /**
-     * Returns the underlying {@link RetrySettings.Builder}, which allows callers to augment the
-     * existing {@link RetrySettings}.
-     */
-    public RetrySettings.Builder retrySettings() {
-      return this.retrySettingsBuilder;
-    }
-
-    /**
-     * Replaces the {@link RetrySettings} for the associated {@link UnaryCallable}.
-     *
-     * <p>When using the method, make sure that the {@link RetrySettings} are complete. For example,
-     * the following code will disable retries because the retry delay is not set:
-     *
-     * <pre>{@code
-     * stubSettings.setRetrySettings(
-     *   RetrySettings.newBuilder()
-     *     .setTotalTimeout(Duration.ofSeconds(10)
-     * );
-     * }</pre>
-     *
-     * @see #retrySettings()
-     */
-    public UnaryCallSettings.Builder<RequestT, ResponseT> setRetrySettings(
-        RetrySettings retrySettings) {
-      this.retrySettingsBuilder = retrySettings.toBuilder();
-      return this;
-    }
-
-    /** Disables retries and sets the RPC timeout. */
-    public UnaryCallSettings.Builder<RequestT, ResponseT> setSimpleTimeoutNoRetries(
-        Duration timeout) {
-      setRetryableCodes();
-      setRetrySettings(
-          RetrySettings.newBuilder()
-              .setTotalTimeout(timeout)
-              .setInitialRetryDelay(Duration.ZERO)
-              .setRetryDelayMultiplier(1)
-              .setMaxRetryDelay(Duration.ZERO)
-              .setInitialRpcTimeout(timeout)
-              .setRpcTimeoutMultiplier(1)
-              .setMaxRpcTimeout(timeout)
-              .setMaxAttempts(1)
-              .build());
-      return this;
-    }
-
-    /**
-     * See the class documentation of {@link UnaryCallSettings} for a description of what retryable
-     * codes do.
-     */
-    public Set<StatusCode.Code> getRetryableCodes() {
-      return this.retryableCodes;
-    }
-
-    /**
-     * Returns an immutable {@link RetrySettings} currently set in this Builder.
-     *
-     * <p>Unlike {@link #retrySettings()}, objects returned by this method are frozen in time.
-     */
-    public RetrySettings getRetrySettings() {
-      return this.retrySettingsBuilder.build();
-    }
-
-    /**
-     * Builds an instance of the containing class. This operation is unsupported on the abstract
-     * base class UnaryCallSettings, but is valid on concrete derived classes.
-     */
-    public UnaryCallSettings<RequestT, ResponseT> build() {
-      return new UnaryCallSettings<>(this);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnaryCallable.java b/gax/src/main/java/com/google/api/gax/rpc/UnaryCallable.java
deleted file mode 100644
index 4a53ec8dc..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnaryCallable.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-
-/**
- * A UnaryCallable is an immutable object which is capable of making RPC calls to non-streaming API
- * methods.
- *
- * <p>In typical usage, the request to send to the remote service will not be bound to the
- * UnaryCallable, but instead is provided at call time, which allows for a UnaryCallable to be saved
- * and used indefinitely.
- *
- * <p>There are two styles of calls that can be made through a UnaryCallable: synchronous and
- * asynchronous.
- *
- * <p>Synchronous example:
- *
- * <pre>{@code
- * RequestType request = RequestType.newBuilder().build();
- * UnaryCallable<RequestType, ResponseType> unaryCallable = api.doSomethingCallable();
- * ResponseType response = unaryCallable.call();
- * }</pre>
- *
- * <p>Asynchronous example:
- *
- * <pre>{@code
- * RequestType request = RequestType.newBuilder().build();
- * UnaryCallable<RequestType, ResponseType> unaryCallable = api.doSomethingCallable();
- * ApiFuture<ResponseType> resultFuture = unaryCallable.futureCall();
- * // do other work
- * // ...
- * ResponseType response = resultFuture.get();
- * }</pre>
- *
- * <p>It is considered advanced usage for a user to create a UnaryCallable themselves. This class is
- * intended to be created by a generated client class, and configured by instances of
- * UnaryCallSettings.Builder which are exposed through the client settings class.
- */
-public abstract class UnaryCallable<RequestT, ResponseT> {
-
-  protected UnaryCallable() {}
-
-  /**
-   * Perform a call asynchronously.
-   *
-   * @param context {@link ApiCallContext} to make the call with
-   * @return {@link ApiFuture} for the call result
-   */
-  public abstract ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context);
-
-  /**
-   * Same as {@link #futureCall(Object, ApiCallContext)}, with a null context.
-   *
-   * @param request request
-   * @return {@link ApiFuture} for the call result
-   */
-  public ApiFuture<ResponseT> futureCall(RequestT request) {
-    return futureCall(request, null);
-  }
-
-  /**
-   * Perform a call synchronously.
-   *
-   * @param request The request to send to the service.
-   * @param context {@link ApiCallContext} to make the call with
-   * @return the call result
-   * @throws ApiException if there is any bad status in the response.
-   * @throws RuntimeException if there is any other exception unrelated to bad status.
-   */
-  public ResponseT call(RequestT request, ApiCallContext context) {
-    return ApiExceptions.callAndTranslateApiException(futureCall(request, context));
-  }
-
-  /**
-   * Same as {@link #call(Object, ApiCallContext)}, with a null context.
-   *
-   * @param request The request to send to the service.
-   * @return the call result
-   * @throws ApiException if there is any bad status in the response.
-   * @throws RuntimeException if there is any other exception unrelated to bad status.
-   */
-  public ResponseT call(RequestT request) {
-    return ApiExceptions.callAndTranslateApiException(futureCall(request));
-  }
-
-  /**
-   * Returns a new {@code UnaryCallable} with an {@link ApiCallContext} that is used as a default
-   * when none is supplied in individual calls.
-   *
-   * @param defaultCallContext the default {@link ApiCallContext}.
-   */
-  public UnaryCallable<RequestT, ResponseT> withDefaultCallContext(
-      final ApiCallContext defaultCallContext) {
-    return new UnaryCallable<RequestT, ResponseT>() {
-      @Override
-      public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext thisCallContext) {
-        return UnaryCallable.this.futureCall(request, defaultCallContext.merge(thisCallContext));
-      }
-    };
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnauthenticatedException.java b/gax/src/main/java/com/google/api/gax/rpc/UnauthenticatedException.java
deleted file mode 100644
index 6daeece5a..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnauthenticatedException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the request does not have valid authentication credentials for the
- * operation.
- */
-public class UnauthenticatedException extends ApiException {
-  public UnauthenticatedException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public UnauthenticatedException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public UnauthenticatedException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnavailableException.java b/gax/src/main/java/com/google/api/gax/rpc/UnavailableException.java
deleted file mode 100644
index 96fbc8d28..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnavailableException.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the service is currently unavailable. This is a most likely a transient
- * condition and may be corrected by retrying with a backoff.
- */
-public class UnavailableException extends ApiException {
-  public UnavailableException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public UnavailableException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public UnavailableException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnimplementedException.java b/gax/src/main/java/com/google/api/gax/rpc/UnimplementedException.java
deleted file mode 100644
index 8e042f441..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnimplementedException.java
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown when the operation is not implemented or not supported/enabled in this service.
- */
-public class UnimplementedException extends ApiException {
-  public UnimplementedException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public UnimplementedException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public UnimplementedException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/UnknownException.java b/gax/src/main/java/com/google/api/gax/rpc/UnknownException.java
deleted file mode 100644
index a3ebe3599..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/UnknownException.java
+++ /dev/null
@@ -1,52 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * Exception thrown due to an unknown error. An example of where this error may be returned is if a
- * Status value received from another address space belongs to an error-space that is not known in
- * this address space. Also errors raised by APIs that do not return enough error information may be
- * converted to this error.
- */
-public class UnknownException extends ApiException {
-  public UnknownException(Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(cause, statusCode, retryable);
-  }
-
-  public UnknownException(
-      String message, Throwable cause, StatusCode statusCode, boolean retryable) {
-    super(message, cause, statusCode, retryable);
-  }
-
-  public UnknownException(
-      Throwable cause, StatusCode statusCode, boolean retryable, ErrorDetails errorDetails) {
-    super(cause, statusCode, retryable, errorDetails);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/Watchdog.java b/gax/src/main/java/com/google/api/gax/rpc/Watchdog.java
deleted file mode 100644
index 8ca97876c..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/Watchdog.java
+++ /dev/null
@@ -1,342 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.common.base.Preconditions;
-import java.util.Iterator;
-import java.util.Map.Entry;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import javax.annotation.Nonnull;
-import javax.annotation.concurrent.GuardedBy;
-import org.threeten.bp.Duration;
-
-/**
- * Prevents the streams from hanging indefinitely. This middleware garbage collects idle streams in
- * case the user forgot to close a ServerStream or if a connection is reset and GRPC does not get
- * notified.
- *
- * <p>For every {@code checkInterval}, this class checks two thresholds:
- *
- * <ul>
- *   <li>waitingTimeout: the amount of time to wait for a response (after the caller signaled
- *       demand) before forcefully closing the stream. Duration.ZERO disables the timeout.
- *   <li>idleTimeout: the amount of time to wait before assuming that the caller forgot to close the
- *       stream and forcefully closing the stream. This is measured from the last time the caller
- *       had no outstanding demand. Duration.ZERO disables the timeout.
- * </ul>
- */
-public final class Watchdog implements Runnable, BackgroundResource {
-
-  private static final Logger LOG = Logger.getLogger(Watchdog.class.getName());
-
-  // Dummy value to convert the ConcurrentHashMap into a Set
-  private static Object PRESENT = new Object();
-  private final ConcurrentHashMap<WatchdogStream, Object> openStreams = new ConcurrentHashMap<>();
-
-  private final ApiClock clock;
-  private final Duration scheduleInterval;
-  private final ScheduledExecutorService executor;
-  private ScheduledFuture<?> future;
-
-  /** returns a Watchdog which is scheduled at the provided interval. */
-  public static Watchdog create(
-      ApiClock clock, Duration scheduleInterval, ScheduledExecutorService executor) {
-    Watchdog watchdog = new Watchdog(clock, scheduleInterval, executor);
-    watchdog.start();
-    return watchdog;
-  }
-
-  private Watchdog(ApiClock clock, Duration scheduleInterval, ScheduledExecutorService executor) {
-    this.clock = Preconditions.checkNotNull(clock, "clock can't be null");
-    this.scheduleInterval = scheduleInterval;
-    this.executor = executor;
-  }
-
-  private void start() {
-    future =
-        executor.scheduleAtFixedRate(
-            this, scheduleInterval.toMillis(), scheduleInterval.toMillis(), TimeUnit.MILLISECONDS);
-  }
-
-  /** Wraps the target observer with timing constraints. */
-  public <ResponseT> ResponseObserver<ResponseT> watch(
-      ResponseObserver<ResponseT> innerObserver,
-      @Nonnull Duration waitTimeout,
-      @Nonnull Duration idleTimeout) {
-    Preconditions.checkNotNull(innerObserver, "innerObserver can't be null");
-    Preconditions.checkNotNull(waitTimeout, "waitTimeout can't be null");
-    Preconditions.checkNotNull(idleTimeout, "idleTimeout can't be null");
-
-    if (waitTimeout.isZero() && idleTimeout.isZero()) {
-      return innerObserver;
-    }
-
-    WatchdogStream<ResponseT> stream =
-        new WatchdogStream<>(innerObserver, waitTimeout, idleTimeout);
-    openStreams.put(stream, PRESENT);
-    return stream;
-  }
-
-  @Override
-  public void run() {
-    try {
-      runUnsafe();
-    } catch (Throwable t) {
-      LOG.log(Level.SEVERE, "Caught throwable in periodic Watchdog run. Continuing.", t);
-    }
-  }
-
-  private void runUnsafe() {
-    Iterator<Entry<WatchdogStream, Object>> it = openStreams.entrySet().iterator();
-
-    while (it.hasNext()) {
-      WatchdogStream stream = it.next().getKey();
-      if (stream.cancelIfStale()) {
-        it.remove();
-      }
-    }
-  }
-
-  @Override
-  public void shutdown() {
-    future.cancel(false);
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return future.isCancelled();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return future.isDone();
-  }
-
-  @Override
-  public void shutdownNow() {
-    future.cancel(true);
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    try {
-      future.get(duration, unit);
-      return true;
-    } catch (ExecutionException | CancellationException e) {
-      return true;
-    } catch (TimeoutException e) {
-      return false;
-    }
-  }
-
-  @Override
-  public void close() {
-    shutdown();
-  }
-
-  enum State {
-    /** Stream has been started, but doesn't have any outstanding requests. */
-    IDLE,
-    /** Stream is awaiting a response from upstream. */
-    WAITING,
-    /**
-     * Stream received a response from upstream, and is awaiting outerResponseObserver processing.
-     */
-    DELIVERING
-  }
-
-  class WatchdogStream<ResponseT> extends StateCheckingResponseObserver<ResponseT> {
-    private final Object lock = new Object();
-
-    private final Duration waitTimeout;
-    private final Duration idleTimeout;
-    private boolean hasStarted;
-    private boolean autoAutoFlowControl = true;
-
-    private final ResponseObserver<ResponseT> outerResponseObserver;
-    private volatile StreamController innerController;
-
-    @GuardedBy("lock")
-    private State state = State.IDLE;
-
-    @GuardedBy("lock")
-    private int pendingCount = 0;
-
-    @GuardedBy("lock")
-    private long lastActivityAt = clock.millisTime();
-
-    private volatile Throwable error;
-
-    WatchdogStream(
-        ResponseObserver<ResponseT> responseObserver, Duration waitTimeout, Duration idleTimeout) {
-      this.waitTimeout = waitTimeout;
-      this.idleTimeout = idleTimeout;
-      this.outerResponseObserver = responseObserver;
-    }
-
-    @Override
-    public void onStartImpl(StreamController controller) {
-      this.innerController = controller;
-      outerResponseObserver.onStart(
-          new StreamController() {
-            @Override
-            public void disableAutoInboundFlowControl() {
-              Preconditions.checkState(
-                  !hasStarted, "Can't disable automatic flow control after the stream has started");
-              autoAutoFlowControl = false;
-              innerController.disableAutoInboundFlowControl();
-            }
-
-            @Override
-            public void request(int count) {
-              WatchdogStream.this.onRequest(count);
-            }
-
-            @Override
-            public void cancel() {
-              WatchdogStream.this.onCancel();
-            }
-          });
-
-      hasStarted = true;
-    }
-
-    private void onRequest(int count) {
-      Preconditions.checkArgument(count > 0, "count must be > 0");
-      Preconditions.checkState(!autoAutoFlowControl, "Auto flow control is enabled");
-
-      // Only reset the request water mark if there are no outstanding requests.
-      synchronized (lock) {
-        if (state == State.IDLE) {
-          state = State.WAITING;
-          lastActivityAt = clock.millisTime();
-        }
-
-        // Increment the request count without overflow
-        int maxIncrement = Integer.MAX_VALUE - pendingCount;
-        count = Math.min(maxIncrement, count);
-        pendingCount += count;
-      }
-      innerController.request(count);
-    }
-
-    private void onCancel() {
-      error = new CancellationException("User cancelled stream");
-      innerController.cancel();
-    }
-
-    @Override
-    public void onResponseImpl(ResponseT response) {
-      synchronized (lock) {
-        state = State.DELIVERING;
-      }
-
-      outerResponseObserver.onResponse(response);
-
-      synchronized (lock) {
-        pendingCount--;
-        lastActivityAt = clock.millisTime();
-
-        if (autoAutoFlowControl || pendingCount > 0) {
-          state = State.WAITING;
-        } else {
-          state = State.IDLE;
-        }
-      }
-    }
-
-    @Override
-    public void onErrorImpl(Throwable t) {
-      // Overlay the cancellation errors (either user or idle)
-      if (this.error != null) {
-        t = this.error;
-      }
-      openStreams.remove(this);
-      outerResponseObserver.onError(t);
-    }
-
-    @Override
-    public void onCompleteImpl() {
-      openStreams.remove(this);
-      outerResponseObserver.onComplete();
-    }
-
-    /**
-     * Checks if this stream has overrun any of its timeouts and cancels it if it does.
-     *
-     * @return True if the stream was canceled.
-     */
-    boolean cancelIfStale() {
-      // If the stream hasn't started yet, innerController will be null. Skip the check this time
-      // and return false so the stream is still watched.
-      if (innerController == null) {
-        return false;
-      }
-
-      Throwable myError = null;
-
-      synchronized (lock) {
-        long waitTime = clock.millisTime() - lastActivityAt;
-
-        switch (this.state) {
-          case IDLE:
-            if (!idleTimeout.isZero() && waitTime >= idleTimeout.toMillis()) {
-              myError = new WatchdogTimeoutException("Canceled due to idle connection", false);
-            }
-            break;
-          case WAITING:
-            if (!waitTimeout.isZero() && waitTime >= waitTimeout.toMillis()) {
-              myError =
-                  new WatchdogTimeoutException(
-                      "Canceled due to timeout waiting for next response", true);
-            }
-            break;
-        }
-      }
-
-      if (myError != null) {
-        this.error = myError;
-        innerController.cancel();
-        return true;
-      }
-      return false;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/WatchdogProvider.java b/gax/src/main/java/com/google/api/gax/rpc/WatchdogProvider.java
deleted file mode 100644
index db3fb20bb..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/WatchdogProvider.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiClock;
-import java.util.concurrent.ScheduledExecutorService;
-import javax.annotation.Nonnull;
-import org.threeten.bp.Duration;
-
-public interface WatchdogProvider {
-  boolean needsClock();
-
-  WatchdogProvider withClock(@Nonnull ApiClock clock);
-
-  boolean needsCheckInterval();
-
-  WatchdogProvider withCheckInterval(Duration checkInterval);
-
-  boolean needsExecutor();
-
-  WatchdogProvider withExecutor(ScheduledExecutorService executor);
-
-  Watchdog getWatchdog();
-
-  /** Return true if the watchdog should be automatically unscheduled. */
-  boolean shouldAutoClose();
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/WatchdogServerStreamingCallable.java b/gax/src/main/java/com/google/api/gax/rpc/WatchdogServerStreamingCallable.java
deleted file mode 100644
index cc3dfec82..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/WatchdogServerStreamingCallable.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Preconditions;
-import org.threeten.bp.Duration;
-
-/**
- * A callable that uses a {@link Watchdog} to monitor streams.
- *
- * <p>It extracts the {@code StreamWaitTimeout} and the {@code StreamIdleTimeout} from the {@link
- * ApiCallContext} and applies then to the stream using the {@link Watchdog}.
- *
- * <p>Package-private for internal use.
- *
- * @see Watchdog for more details
- */
-class WatchdogServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-  private final ServerStreamingCallable<RequestT, ResponseT> inner;
-  private final Watchdog watchdog;
-
-  WatchdogServerStreamingCallable(
-      ServerStreamingCallable<RequestT, ResponseT> inner, Watchdog watchdog) {
-    Preconditions.checkNotNull(inner);
-    Preconditions.checkNotNull(watchdog);
-
-    this.inner = inner;
-    this.watchdog = watchdog;
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    // If the caller never configured the timeouts, disable them
-    Duration waitTimeout = MoreObjects.firstNonNull(context.getStreamWaitTimeout(), Duration.ZERO);
-    Duration idleTimeout = MoreObjects.firstNonNull(context.getStreamIdleTimeout(), Duration.ZERO);
-
-    responseObserver = watchdog.watch(responseObserver, waitTimeout, idleTimeout);
-    inner.call(request, responseObserver, context);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/WatchdogTimeoutException.java b/gax/src/main/java/com/google/api/gax/rpc/WatchdogTimeoutException.java
deleted file mode 100644
index 15b0cc388..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/WatchdogTimeoutException.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-/**
- * The marker exception thrown when a timeout is exceeded.
- *
- * <p>This error can be thrown under 2 circumstances:
- *
- * <ul>
- *   <li>A wait timeout has exceeded, which means that the client timed out waiting for the next
- *       message from the server. In this case, {@link #isRetryable()} will be true.
- *   <li>An idle timeout has exceeded, which means that the stream is using manual flow control and
- *       the caller has not called {@link StreamController#request(int)} (in case of callback api)
- *       or next on {@link ServerStream#iterator()} (in case of blocking api).
- * </ul>
- */
-public class WatchdogTimeoutException extends ApiException {
-  private static final long serialVersionUID = -777463630112442086L;
-
-  public static final StatusCode LOCAL_ABORTED_STATUS_CODE =
-      new StatusCode() {
-        @Override
-        public Code getCode() {
-          return Code.ABORTED;
-        }
-
-        @Override
-        public Object getTransportCode() {
-          return null;
-        }
-      };
-
-  /** Package private for internal use. */
-  WatchdogTimeoutException(String message, boolean retry) {
-    super(message, null, LOCAL_ABORTED_STATUS_CODE, retry);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/internal/ApiCallContextOptions.java b/gax/src/main/java/com/google/api/gax/rpc/internal/ApiCallContextOptions.java
deleted file mode 100644
index a0873f309..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/internal/ApiCallContextOptions.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.internal;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiCallContext.Key;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-
-/**
- * ApiCallContextOptions encapsulates additional call options to pass in a {@link ApiCallContext}
- */
-@InternalApi
-public final class ApiCallContextOptions {
-
-  private final ImmutableMap<Key, Object> options;
-  private static final ApiCallContextOptions DEFAULT_OPTIONS =
-      new ApiCallContextOptions(ImmutableMap.<Key, Object>of());
-
-  private ApiCallContextOptions(ImmutableMap<Key, Object> options) {
-    this.options = Preconditions.checkNotNull(options);
-  }
-
-  public static ApiCallContextOptions getDefaultOptions() {
-    return DEFAULT_OPTIONS;
-  }
-
-  /** Add an option. Any existing value of the key is overwritten. */
-  public <T> ApiCallContextOptions withOption(Key<T> key, T value) {
-    Preconditions.checkNotNull(key);
-    Preconditions.checkNotNull(value);
-    ImmutableMap.Builder<Key, Object> builder = ImmutableMap.builder();
-    if (!options.containsKey(key)) {
-      builder.putAll(options).put(key, value);
-    } else {
-      builder.put(key, value);
-      for (Key oldKey : options.keySet()) {
-        if (!oldKey.equals(key)) {
-          builder.put(oldKey, options.get(oldKey));
-        }
-      }
-    }
-    return new ApiCallContextOptions(builder.build());
-  }
-
-  /** Get an option. */
-  public <T> T getOption(Key<T> key) {
-    Preconditions.checkNotNull(key);
-    return (T) options.get(key);
-  }
-
-  /** Merge new options into existing ones. Any existing values of the keys are overwritten. */
-  public ApiCallContextOptions merge(ApiCallContextOptions newOptions) {
-    Preconditions.checkNotNull(newOptions);
-    ImmutableMap.Builder<Key, Object> builder =
-        ImmutableMap.<Key, Object>builder().putAll(newOptions.options);
-    for (Key key : options.keySet()) {
-      if (!newOptions.options.containsKey(key)) {
-        builder.put(key, options.get(key));
-      }
-    }
-    return new ApiCallContextOptions(builder.build());
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/internal/EnvironmentProvider.java b/gax/src/main/java/com/google/api/gax/rpc/internal/EnvironmentProvider.java
deleted file mode 100644
index af623f4b0..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/internal/EnvironmentProvider.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.internal;
-
-import com.google.api.core.InternalExtensionOnly;
-
-/** Provides an interface to provide the environment variable values. */
-@InternalExtensionOnly
-public interface EnvironmentProvider {
-  /** Returns the environment variable value. */
-  String getenv(String name);
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/internal/Headers.java b/gax/src/main/java/com/google/api/gax/rpc/internal/Headers.java
deleted file mode 100644
index ddd660036..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/internal/Headers.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.internal;
-
-import com.google.api.core.InternalApi;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import java.util.List;
-import java.util.Map;
-
-@InternalApi
-public class Headers {
-  public static ImmutableMap<String, List<String>> mergeHeaders(
-      Map<String, List<String>> oldHeaders, Map<String, List<String>> newHeaders) {
-    ImmutableMap.Builder<String, List<String>> headersBuilder = ImmutableMap.builder();
-    for (Map.Entry<String, List<String>> entry : oldHeaders.entrySet()) {
-      String key = entry.getKey();
-      List<String> oldValue = entry.getValue();
-      List<String> newValue = newHeaders.get(key);
-      ImmutableList.Builder<String> mergedValueBuilder = ImmutableList.builder();
-      mergedValueBuilder.addAll(oldValue);
-      if (newValue != null) {
-        mergedValueBuilder.addAll(newValue);
-      }
-      headersBuilder.put(key, mergedValueBuilder.build());
-    }
-    for (Map.Entry<String, List<String>> entry : newHeaders.entrySet()) {
-      String key = entry.getKey();
-      if (!oldHeaders.containsKey(key)) {
-        headersBuilder.put(key, ImmutableList.copyOf(entry.getValue()));
-      }
-    }
-    return headersBuilder.build();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentials.java b/gax/src/main/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentials.java
deleted file mode 100644
index 51bbade9a..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentials.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.internal;
-
-import com.google.api.client.util.Beta;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableMap;
-import java.io.IOException;
-import java.net.URI;
-import java.util.List;
-import java.util.Map;
-
-/**
- * {@code QuotaProjectIdHidingCredentials} is intended to be used to wrap a {@link Credentials} to
- * hide quota project id
- *
- * <p>Ensure that a custom set quota project id takes priority over one detected by credentials.
- */
-@Beta
-public class QuotaProjectIdHidingCredentials extends Credentials {
-  private static final String QUOTA_PROJECT_ID_HEADER_KEY = "x-goog-user-project";
-  private final Credentials wrappedCredentials;
-
-  public QuotaProjectIdHidingCredentials(Credentials credentials) {
-    this.wrappedCredentials = credentials;
-  }
-
-  @Override
-  public String getAuthenticationType() {
-    return this.wrappedCredentials.getAuthenticationType();
-  }
-
-  @Override
-  public Map<String, List<String>> getRequestMetadata(URI uri) throws IOException {
-    ImmutableMap.Builder<String, List<String>> metaBuilder = ImmutableMap.builder();
-    for (Map.Entry<String, List<String>> entry :
-        this.wrappedCredentials.getRequestMetadata(uri).entrySet()) {
-      if (entry.getKey().equals(QUOTA_PROJECT_ID_HEADER_KEY)) {
-        continue;
-      }
-      metaBuilder.put(entry);
-    }
-    return metaBuilder.build();
-  }
-
-  @Override
-  public Map<String, List<String>> getRequestMetadata() throws IOException {
-    return this.getRequestMetadata(null);
-  }
-
-  @Override
-  public boolean hasRequestMetadata() {
-    return this.wrappedCredentials.hasRequestMetadata();
-  }
-
-  @Override
-  public boolean hasRequestMetadataOnly() {
-    return this.wrappedCredentials.hasRequestMetadataOnly();
-  }
-
-  @Override
-  public void refresh() throws IOException {
-    this.wrappedCredentials.refresh();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/mtls/ContextAwareMetadataJson.java b/gax/src/main/java/com/google/api/gax/rpc/mtls/ContextAwareMetadataJson.java
deleted file mode 100644
index 25d7d27de..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/mtls/ContextAwareMetadataJson.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.mtls;
-
-import com.google.api.client.json.GenericJson;
-import com.google.api.client.util.Key;
-import com.google.api.core.BetaApi;
-import com.google.common.collect.ImmutableList;
-import java.util.List;
-
-/** Data class representing context_aware_metadata.json file. */
-@BetaApi
-public class ContextAwareMetadataJson extends GenericJson {
-  /** Cert provider command */
-  @Key("cert_provider_command")
-  private List<String> commands;
-
-  /** Returns the cert provider command. */
-  public final ImmutableList<String> getCommands() {
-    return ImmutableList.copyOf(commands);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/rpc/mtls/MtlsProvider.java b/gax/src/main/java/com/google/api/gax/rpc/mtls/MtlsProvider.java
deleted file mode 100644
index c24fc80d6..000000000
--- a/gax/src/main/java/com/google/api/gax/rpc/mtls/MtlsProvider.java
+++ /dev/null
@@ -1,184 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.mtls;
-
-import com.google.api.client.json.JsonParser;
-import com.google.api.client.json.gson.GsonFactory;
-import com.google.api.client.util.SecurityUtils;
-import com.google.api.core.BetaApi;
-import com.google.api.gax.rpc.internal.EnvironmentProvider;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.ImmutableList;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.security.GeneralSecurityException;
-import java.security.KeyStore;
-import java.util.List;
-
-/**
- * Provider class for mutual TLS. It is used to configure the mutual TLS in the transport with the
- * default client certificate on device.
- */
-@BetaApi
-public class MtlsProvider {
-  interface ProcessProvider {
-    public Process createProcess(InputStream metadata) throws IOException;
-  }
-
-  static class DefaultProcessProvider implements ProcessProvider {
-    @Override
-    public Process createProcess(InputStream metadata) throws IOException {
-      if (metadata == null) {
-        return null;
-      }
-      List<String> command = extractCertificateProviderCommand(metadata);
-      return new ProcessBuilder(command).start();
-    }
-  }
-
-  private static final String DEFAULT_CONTEXT_AWARE_METADATA_PATH =
-      System.getProperty("user.home") + "/.secureConnect/context_aware_metadata.json";
-
-  private String metadataPath;
-  private EnvironmentProvider envProvider;
-  private ProcessProvider processProvider;
-
-  /**
-   * The policy for mutual TLS endpoint usage. NEVER means always use regular endpoint; ALWAYS means
-   * always use mTLS endpoint; AUTO means auto switch to mTLS endpoint if client certificate exists
-   * and should be used.
-   */
-  public enum MtlsEndpointUsagePolicy {
-    NEVER,
-    AUTO,
-    ALWAYS;
-  }
-
-  @VisibleForTesting
-  MtlsProvider(
-      EnvironmentProvider envProvider, ProcessProvider processProvider, String metadataPath) {
-    this.envProvider = envProvider;
-    this.processProvider = processProvider;
-    this.metadataPath = metadataPath;
-  }
-
-  public MtlsProvider() {
-    this(System::getenv, new DefaultProcessProvider(), DEFAULT_CONTEXT_AWARE_METADATA_PATH);
-  }
-
-  /**
-   * Returns if mutual TLS client certificate should be used. If the value is true, the key store
-   * from {@link #getKeyStore()} will be used to configure mutual TLS transport.
-   */
-  public boolean useMtlsClientCertificate() {
-    String useClientCertificate = envProvider.getenv("GOOGLE_API_USE_CLIENT_CERTIFICATE");
-    return "true".equals(useClientCertificate);
-  }
-
-  /** Returns the current mutual TLS endpoint usage policy. */
-  public MtlsEndpointUsagePolicy getMtlsEndpointUsagePolicy() {
-    String mtlsEndpointUsagePolicy = envProvider.getenv("GOOGLE_API_USE_MTLS_ENDPOINT");
-    if ("never".equals(mtlsEndpointUsagePolicy)) {
-      return MtlsEndpointUsagePolicy.NEVER;
-    } else if ("always".equals(mtlsEndpointUsagePolicy)) {
-      return MtlsEndpointUsagePolicy.ALWAYS;
-    }
-    return MtlsEndpointUsagePolicy.AUTO;
-  }
-
-  /** The mutual TLS key store created with the default client certificate on device. */
-  public KeyStore getKeyStore() throws IOException {
-    try (InputStream stream = new FileInputStream(metadataPath)) {
-      return getKeyStore(stream, processProvider);
-    } catch (InterruptedException e) {
-      throw new IOException("Interrupted executing certificate provider command", e);
-    } catch (GeneralSecurityException e) {
-      // Return null as if the file doesn't exist.
-      return null;
-    } catch (FileNotFoundException exception) {
-      // If the metadata file doesn't exist, then there is no key store, just return null.
-      return null;
-    }
-  }
-
-  @VisibleForTesting
-  static KeyStore getKeyStore(InputStream metadata, ProcessProvider processProvider)
-      throws IOException, InterruptedException, GeneralSecurityException {
-    Process process = processProvider.createProcess(metadata);
-
-    // Run the command and timeout after 1000 milliseconds.
-    int exitCode = runCertificateProviderCommand(process, 1000);
-    if (exitCode != 0) {
-      throw new IOException("Cert provider command failed with exit code: " + exitCode);
-    }
-
-    // Create mTLS key store with the input certificates from shell command.
-    return SecurityUtils.createMtlsKeyStore(process.getInputStream());
-  }
-
-  @VisibleForTesting
-  static ImmutableList<String> extractCertificateProviderCommand(InputStream contextAwareMetadata)
-      throws IOException {
-    JsonParser parser = new GsonFactory().createJsonParser(contextAwareMetadata);
-    ContextAwareMetadataJson json = parser.parse(ContextAwareMetadataJson.class);
-    return json.getCommands();
-  }
-
-  @VisibleForTesting
-  static int runCertificateProviderCommand(Process commandProcess, long timeoutMilliseconds)
-      throws IOException, InterruptedException {
-    long startTime = System.currentTimeMillis();
-    long remainTime = timeoutMilliseconds;
-
-    // In the while loop, keep checking if the process is terminated every 100 milliseconds
-    // until timeout is reached or process is terminated. In getKeyStore we set timeout to
-    // 1000 milliseconds, so 100 millisecond is a good number for the sleep.
-    while (remainTime > 0) {
-      Thread.sleep(Math.min(remainTime + 1, 100));
-      remainTime -= System.currentTimeMillis() - startTime;
-
-      try {
-        return commandProcess.exitValue();
-      } catch (IllegalThreadStateException ignored) {
-        // exitValue throws IllegalThreadStateException if process has not yet terminated.
-        // Once the process is terminated, exitValue no longer throws exception. Therefore
-        // in the while loop, we use exitValue to check if process is terminated. See
-        // https://docs.oracle.com/javase/7/docs/api/java/lang/Process.html#exitValue()
-        // for more details.
-      }
-    }
-
-    commandProcess.destroy();
-    throw new IOException("cert provider command timed out");
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/ApiTracer.java b/gax/src/main/java/com/google/api/gax/tracing/ApiTracer.java
deleted file mode 100644
index 3176be4b9..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/ApiTracer.java
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-import org.threeten.bp.Duration;
-
-/**
- * Implementations of this class trace the logical flow of a google cloud client.
- *
- * <p>A single instance of a tracer represents a logical operation that can be annotated throughout
- * its lifecycle. Constructing an instance of a subclass will implicitly signal the start of a new
- * operation.
- *
- * <p>For internal use only. google-cloud-java libraries should extend {@link BaseApiTracer}.
- */
-@InternalApi
-public interface ApiTracer {
-
-  /**
-   * Asks the underlying implementation to install itself as a thread local. This allows for interop
-   * between clients using gax and external resources to share the same implementation of the
-   * tracing. For example OpenCensus will install a thread local that can read by the GRPC.
-   */
-  Scope inScope();
-
-  /**
-   * Signals that the overall operation has finished successfully. The tracer is now considered
-   * closed and should no longer be used.
-   */
-  void operationSucceeded();
-
-  /**
-   * Signals that the operation was cancelled by the user. The tracer is now considered closed and
-   * should no longer be used.
-   */
-  void operationCancelled();
-
-  /**
-   * Signals that the overall operation has failed and no further attempts will be made. The tracer
-   * is now considered closed and should no longer be used.
-   *
-   * @param error the final error that caused the operation to fail.
-   */
-  void operationFailed(Throwable error);
-
-  /**
-   * Annotates the operation with selected connection id from the {@code ChannelPool}.
-   *
-   * @param id the local connection identifier of the selected connection.
-   */
-  void connectionSelected(String id);
-
-  /**
-   * Adds an annotation that an attempt is about to start. In general this should occur at the very
-   * start of the operation. The attemptNumber is zero based. So the initial attempt will be 0.
-   *
-   * @param attemptNumber the zero based sequential attempt number.
-   * @deprecated Please use {@link #attemptStarted(Object, int)} instead.
-   */
-  @Deprecated
-  void attemptStarted(int attemptNumber);
-
-  /**
-   * Adds an annotation that an attempt is about to start with additional information from the
-   * request. In general this should occur at the very start of the operation. The attemptNumber is
-   * zero based. So the initial attempt will be 0.
-   *
-   * @param attemptNumber the zero based sequential attempt number.
-   * @param request request of this attempt.
-   */
-  void attemptStarted(Object request, int attemptNumber);
-
-  /** Adds an annotation that the attempt succeeded. */
-  void attemptSucceeded();
-
-  /** Add an annotation that the attempt was cancelled by the user. */
-  void attemptCancelled();
-
-  /**
-   * Adds an annotation that the attempt failed, but another attempt will be made after the delay.
-   *
-   * @param error the transient error that caused the attempt to fail.
-   * @param delay the amount of time to wait before the next attempt will start.
-   */
-  void attemptFailed(Throwable error, Duration delay);
-
-  /**
-   * Adds an annotation that the attempt failed and that no further attempts will be made because
-   * retry limits have been reached.
-   *
-   * @param error the last error received before retries were exhausted.
-   */
-  void attemptFailedRetriesExhausted(Throwable error);
-
-  /**
-   * Adds an annotation that the attempt failed and that no further attempts will be made because
-   * the last error was not retryable.
-   *
-   * @param error the error that caused the final attempt to fail.
-   */
-  void attemptPermanentFailure(Throwable error);
-
-  /**
-   * Signals that the initial RPC for the long running operation failed.
-   *
-   * @param error the error that caused the long running operation fail.
-   */
-  void lroStartFailed(Throwable error);
-
-  /**
-   * Signals that the initial RPC successfully started the long running operation. The long running
-   * operation will now be polled for completion.
-   */
-  void lroStartSucceeded();
-
-  /** Adds an annotation that a streaming response has been received. */
-  void responseReceived();
-
-  /** Adds an annotation that a streaming request has been sent. */
-  void requestSent();
-
-  /**
-   * Adds an annotation that a batch of writes has been flushed.
-   *
-   * @param elementCount the number of elements in the batch.
-   * @param requestSize the size of the batch in bytes.
-   */
-  void batchRequestSent(long elementCount, long requestSize);
-
-  /**
-   * A context class to be used with {@link #inScope()} and a try-with-resources block. Closing a
-   * {@link Scope} removes any context that the underlying implementation might've set in {@link
-   * #inScope()}.
-   */
-  interface Scope extends AutoCloseable {
-    @Override
-    void close();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/ApiTracerFactory.java b/gax/src/main/java/com/google/api/gax/tracing/ApiTracerFactory.java
deleted file mode 100644
index bb8345b88..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/ApiTracerFactory.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.core.InternalExtensionOnly;
-
-/**
- * A factory to create new instances of {@link ApiTracer}s.
- *
- * <p>In general a single instance of an {@link ApiTracer} will correspond to a single logical
- * operation.
- *
- * <p>For internal use only. google-cloud-java libraries should extend {@link BaseApiTracerFactory}.
- */
-@InternalApi
-@InternalExtensionOnly
-public interface ApiTracerFactory {
-  /** The type of operation the {@link ApiTracer} is tracing. */
-  enum OperationType {
-    Unary,
-    Batching,
-    LongRunning,
-    ServerStreaming,
-    ClientStreaming,
-    BidiStreaming
-  }
-
-  /**
-   * Create a new {@link ApiTracer} that will be a child of the current context.
-   *
-   * @param parent the parent of this tracer
-   * @param spanName the name of the new span
-   * @param operationType the type of operation that the tracer will trace
-   */
-  ApiTracer newTracer(ApiTracer parent, SpanName spanName, OperationType operationType);
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracer.java b/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracer.java
deleted file mode 100644
index 538708b87..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracer.java
+++ /dev/null
@@ -1,143 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-import org.threeten.bp.Duration;
-
-/**
- * A base implementation of {@link ApiTracer} that does nothing.
- *
- * <p>For internal use only.
- */
-@InternalApi("For internal use by google-cloud-java clients only")
-public class BaseApiTracer implements ApiTracer {
-  private static final ApiTracer INSTANCE = new BaseApiTracer();
-
-  private static final Scope NOOP_SCOPE =
-      new Scope() {
-        @Override
-        public void close() {
-          // noop
-        }
-      };
-
-  protected BaseApiTracer() {}
-
-  public static ApiTracer getInstance() {
-    return INSTANCE;
-  }
-
-  @Override
-  public Scope inScope() {
-    return NOOP_SCOPE;
-  }
-
-  @Override
-  public void operationSucceeded() {
-    // noop
-  }
-
-  @Override
-  public void operationCancelled() {
-    // noop
-  }
-
-  @Override
-  public void operationFailed(Throwable error) {
-    // noop
-  }
-
-  @Override
-  public void connectionSelected(String id) {
-    // noop
-  }
-
-  @Override
-  public void attemptStarted(int attemptNumber) {
-    // noop
-  }
-
-  @Override
-  public void attemptStarted(Object request, int attemptNumber) {
-    attemptStarted(attemptNumber);
-  }
-
-  @Override
-  public void attemptSucceeded() {
-    // noop
-  }
-
-  @Override
-  public void attemptCancelled() {
-    // noop
-  }
-
-  @Override
-  public void attemptFailed(Throwable error, Duration delay) {
-    // noop
-  }
-
-  @Override
-  public void attemptFailedRetriesExhausted(Throwable error) {
-    // noop
-  }
-
-  @Override
-  public void attemptPermanentFailure(Throwable error) {
-    // noop
-
-  }
-
-  @Override
-  public void lroStartFailed(Throwable error) {
-    // noop
-  }
-
-  @Override
-  public void lroStartSucceeded() {
-    // noop
-  }
-
-  @Override
-  public void responseReceived() {
-    // noop
-  }
-
-  @Override
-  public void requestSent() {
-    // noop
-  }
-
-  @Override
-  public void batchRequestSent(long elementCount, long requestSize) {
-    // noop
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracerFactory.java b/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracerFactory.java
deleted file mode 100644
index 0b04bf872..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/BaseApiTracerFactory.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-
-/**
- * Base factory that will build {@link ApiTracer}s that do nothing.
- *
- * <p>For internal use only.
- */
-@InternalApi("For internal use by google-cloud-java clients only")
-public class BaseApiTracerFactory implements ApiTracerFactory {
-  private static final BaseApiTracerFactory INSTANCE = new BaseApiTracerFactory();
-
-  public static BaseApiTracerFactory getInstance() {
-    return INSTANCE;
-  }
-
-  protected BaseApiTracerFactory() {}
-
-  /** {@inheritDoc} */
-  @Override
-  public ApiTracer newTracer(ApiTracer parent, SpanName spanName, OperationType operationType) {
-    return BaseApiTracer.getInstance();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracer.java b/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracer.java
deleted file mode 100644
index ea4c5f903..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracer.java
+++ /dev/null
@@ -1,492 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.base.Preconditions;
-import com.google.common.base.Strings;
-import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.EndSpanOptions;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Status;
-import io.opencensus.trace.Status.CanonicalCode;
-import io.opencensus.trace.Tracer;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicLong;
-import javax.annotation.Nonnull;
-import org.threeten.bp.Duration;
-
-/**
- * Implementation of {@link ApiTracer} that uses OpenCensus.
- *
- * <p>This implementation wraps an OpenCensus {@link Span} for every tracer and annotates that
- * {@link Span} with various events throughout the lifecycle of the logical operation.
- *
- * <p>Each span will be named {@code ClientName.MethodName} and will have the following attributes:
- *
- * <dl>
- *   <dt>{@code attempt count}
- *   <dd>The Number of attempts sent before the logical operation completed
- *   <dt>{@code status}
- *   <dd>The status code of the last attempt
- *   <dt>{@code total response count}
- *   <dd>The number of messages received across all of the attempts. This will only be set for
- *       server streaming and bidi RPCs.
- *   <dt>{@code total request count}
- *   <dd>The number of messages sent across all of the attempts. This will only be set for client
- *       streaming and bidi RPCs.
- *   <dt>{@code batch count}
- *   <dd>For batch requests, the number of elements in the request.
- *   <dt>{@code batch size}
- *   <dd>For batch requests, the byte size of the request.
- * </dl>
- *
- * <p>The spans will contain the following annotations:
- *
- * <ul>
- *   <li>{@code Attempt cancelled} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential attempt number
- *         <dt>{@code attempt request count}
- *         <dd>The number of requests sent in this attempt. This will only be set for client
- *             streaming and bidi RPCs.
- *         <dt>{@code attempt response count}
- *         <dd>The number of responses received in this attempt. This will only be set for server
- *             streaming and bidi RPCs.
- *         <dt>{@code connection}
- *         <dd>The UUID of the connection which the attempt was sent.
- *       </dl>
- *   <li>{@code Attempt failed, scheduling next attempt} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential attempt number
- *         <dt>{@code status}
- *         <dd>The status code of the failed attempt
- *         <dt>{@code delay}
- *         <dd>The number of milliseconds to wait before trying again
- *         <dt>{@code attempt request count}
- *         <dd>The number of requests sent in this attempt. This will only be set for client
- *             streaming and bidi RPCs.
- *         <dt>{@code attempt response count}
- *         <dd>The number of responses received in this attempt. This will only be set for server
- *             streaming and bidi RPCs.
- *         <dt>{@code connection}
- *         <dd>The UUID of the connection which the attempt was sent.
- *       </dl>
- *   <li>{@code Attempts exhausted} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential attempt number
- *         <dt>{@code status}
- *         <dd>The status code of the failed attempt
- *         <dt>{@code attempt request count}
- *         <dd>The number of requests sent in this attempt. This will only be set for client
- *             streaming and bidi RPCs.
- *         <dt>{@code attempt response count}
- *         <dd>The number of responses received in this attempt. This will only be set for server
- *             streaming and bidi RPCs.
- *         <dt>{@code connection}
- *         <dd>The UUID of the connection which the attempt was sent.
- *       </dl>
- *   <li>{@code Attempt failed, error not retryable} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential attempt number
- *         <dt>{@code status}
- *         <dd>The status code of the failed attempt
- *         <dt>{@code attempt request count}
- *         <dd>The number of requests sent in this attempt. This will only be set for client
- *             streaming and bidi RPCs.
- *         <dt>{@code attempt response count}
- *         <dd>The number of responses received in this attempt. This will only be set for server
- *             streaming and bidi RPCs.
- *         <dt>{@code connection}
- *         <dd>The UUID of the connection which the attempt was sent.
- *       </dl>
- *   <li>{@code Attempt succeeded} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential attempt number
- *         <dt>{@code attempt request count}
- *         <dd>The number of requests sent in this attempt. This will only be set for client
- *             streaming and bidi RPCs.
- *         <dt>{@code attempt response count}
- *         <dd>The number of responses received in this attempt. This will only be set for server
- *             streaming and bidi RPCs.
- *         <dt>{@code connection}
- *         <dd>The UUID of the connection which the attempt was sent.
- *       </dl>
- * </ul>
- *
- * <p>Long running operations, which are composed of an initial RPC to start the operation and a
- * number of polling RPCs will be represented as a tree of spans. The top level span will be named
- * after the initial RPC name suffixed with "Operation" and will have the following annotations:
- *
- * <ul>
- *   <li>{@code Operation started}
- *   <li>{@code Operation failed to start} with the following attributes:
- *       <dl>
- *         <dt>{@code status}
- *         <dd>The status code of why the operation failed to start
- *       </dl>
- *   <li>{@code Polling was cancelled} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential poll number.
- *         <dt>{@code attempt request count}
- *       </dl>
- *   <li>{@code Scheduling next poll} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential poll number
- *         <dt>{@code status}
- *         <dd>OK if the poll succeeded, but the operation is still running.
- *         <dt>{@code delay}
- *         <dd>The number of milliseconds to wait before polling again
- *       </dl>
- *   <li>{@code Polling attempts exhausted} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential poll number
- *         <dt>{@code status}
- *         <dd>OK if the poll succeeded, but the operation is still running.
- *       </dl>
- *   <li>{@code Polling failed} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential poll number
- *         <dt>{@code status}
- *         <dd>OK if the poll succeeded, but the operation is still running.
- *       </dl>
- *   <li>{@code Polling completed} with the following attributes:
- *       <dl>
- *         <dt>{@code attempt}
- *         <dd>Zero based sequential poll number
- *       </dl>
- * </ul>
- *
- * <p>The toplevel long running operation span will also contain child spans to describe the retry
- * attempts for the initial RPC and each poll as described in the general span section above.
- *
- * <p>This class is thread compatible. It expects callers to follow grpc's threading model: there is
- * only one thread that invokes the operation* and attempt* methods. Please see {@link
- * com.google.api.gax.rpc.ApiStreamObserver} for more information.
- */
-@BetaApi("Surface for tracing is not yet stable")
-public class OpencensusTracer extends BaseApiTracer {
-  private final Tracer tracer;
-  private final Span span;
-  private final OperationType operationType;
-
-  private volatile String lastConnectionId;
-  private volatile long currentAttemptId;
-  private AtomicLong attemptSentMessages = new AtomicLong(0);
-  private long attemptReceivedMessages = 0;
-  private AtomicLong totalSentMessages = new AtomicLong(0);
-  private long totalReceivedMessages = 0;
-
-  OpencensusTracer(
-      @Nonnull Tracer tracer, @Nonnull Span span, @Nonnull OperationType operationType) {
-    this.tracer = Preconditions.checkNotNull(tracer, "tracer can't be null");
-    this.span = Preconditions.checkNotNull(span, "span can't be null");
-    this.operationType = Preconditions.checkNotNull(operationType, "operationType can't be null");
-  }
-
-  Span getSpan() {
-    return span;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public Scope inScope() {
-    // Suppressing to make MustBeClosedChecker happy. The scope will be closed but indirectly
-    // (inside new Scope()), and the checker cannot recognize it.
-    @SuppressWarnings("MustBeClosedChecker")
-    final io.opencensus.common.Scope scope = tracer.withSpan(span);
-
-    return new Scope() {
-      @Override
-      public void close() {
-        scope.close();
-      }
-    };
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void operationSucceeded() {
-    Map<String, AttributeValue> attributes = baseOperationAttributes();
-
-    span.putAttributes(attributes);
-    span.end();
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void operationCancelled() {
-    Map<String, AttributeValue> attributes = baseOperationAttributes();
-    span.putAttributes(attributes);
-    span.end(
-        EndSpanOptions.builder()
-            .setStatus(Status.CANCELLED.withDescription("Cancelled by caller"))
-            .build());
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void operationFailed(Throwable error) {
-    Map<String, AttributeValue> attributes = baseOperationAttributes();
-
-    span.putAttributes(attributes);
-    span.end(EndSpanOptions.builder().setStatus(convertErrorToStatus(error)).build());
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void lroStartFailed(Throwable error) {
-    Map<String, AttributeValue> attributes = new HashMap<>();
-    populateError(attributes, error);
-
-    span.addAnnotation("Operation failed to start", attributes);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void lroStartSucceeded() {
-    span.addAnnotation("Operation started");
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void connectionSelected(String id) {
-    lastConnectionId = id;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptStarted(int attemptNumber) {
-    currentAttemptId = attemptNumber;
-    attemptSentMessages.set(0);
-    attemptReceivedMessages = 0;
-
-    // NOTE: no annotations are added because they don't provide any semantic value.
-    // This simply is used for state management.
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptStarted(Object request, int attemptNumber) {
-    attemptStarted(attemptNumber);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptSucceeded() {
-    Map<String, AttributeValue> attributes = baseAttemptAttributes();
-
-    // Same infrastructure is used for both polling and retries, so need to disambiguate it here.
-    if (operationType == OperationType.LongRunning) {
-      span.addAnnotation("Polling completed", attributes);
-    } else {
-      span.addAnnotation("Attempt succeeded", attributes);
-    }
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptCancelled() {
-    Map<String, AttributeValue> attributes = baseAttemptAttributes();
-
-    // Same infrastructure is used for both polling and retries, so need to disambiguate it here.
-    if (operationType == OperationType.LongRunning) {
-      span.addAnnotation("Polling was cancelled", attributes);
-    } else {
-      span.addAnnotation("Attempt cancelled", attributes);
-    }
-    lastConnectionId = null;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptFailed(Throwable error, Duration delay) {
-    Map<String, AttributeValue> attributes = baseAttemptAttributes();
-    attributes.put("delay ms", AttributeValue.longAttributeValue(delay.toMillis()));
-    populateError(attributes, error);
-
-    // Same infrastructure is used for both polling and retries, so need to disambiguate it here.
-    if (operationType == OperationType.LongRunning) {
-      // The poll RPC was successful, but it indicated that the operation is still running.
-      span.addAnnotation("Scheduling next poll", attributes);
-    } else {
-      span.addAnnotation("Attempt failed, scheduling next attempt", attributes);
-    }
-    lastConnectionId = null;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptFailedRetriesExhausted(Throwable error) {
-    Map<String, AttributeValue> attributes = baseAttemptAttributes();
-    populateError(attributes, error);
-
-    // Same infrastructure is used for both polling and retries, so need to disambiguate it here.
-    if (operationType == OperationType.LongRunning) {
-      span.addAnnotation("Polling attempts exhausted", attributes);
-    } else {
-      span.addAnnotation("Attempts exhausted", attributes);
-    }
-    lastConnectionId = null;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void attemptPermanentFailure(Throwable error) {
-    Map<String, AttributeValue> attributes = baseAttemptAttributes();
-    populateError(attributes, error);
-
-    // Same infrastructure is used for both polling and retries, so need to disambiguate it here.
-    if (operationType == OperationType.LongRunning) {
-      span.addAnnotation("Polling failed", attributes);
-    } else {
-      span.addAnnotation("Attempt failed, error not retryable", attributes);
-    }
-    lastConnectionId = null;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void responseReceived() {
-    attemptReceivedMessages++;
-    totalReceivedMessages++;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void requestSent() {
-    attemptSentMessages.incrementAndGet();
-    totalSentMessages.incrementAndGet();
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public void batchRequestSent(long elementCount, long requestSize) {
-    span.putAttribute("batch count", AttributeValue.longAttributeValue(elementCount));
-    span.putAttribute("batch size", AttributeValue.longAttributeValue(requestSize));
-  }
-
-  private Map<String, AttributeValue> baseOperationAttributes() {
-    HashMap<String, AttributeValue> attributes = new HashMap<>();
-
-    attributes.put("attempt count", AttributeValue.longAttributeValue(currentAttemptId + 1));
-
-    long localTotalSentMessages = totalSentMessages.get();
-    if (localTotalSentMessages > 0) {
-      attributes.put(
-          "total request count", AttributeValue.longAttributeValue(localTotalSentMessages));
-    }
-    if (totalReceivedMessages > 0) {
-      attributes.put(
-          "total response count", AttributeValue.longAttributeValue(totalReceivedMessages));
-    }
-
-    return attributes;
-  }
-
-  private Map<String, AttributeValue> baseAttemptAttributes() {
-    HashMap<String, AttributeValue> attributes = new HashMap<>();
-
-    populateAttemptNumber(attributes);
-
-    long localAttemptSentMessages = attemptSentMessages.get();
-    if (localAttemptSentMessages > 0) {
-      attributes.put(
-          "attempt request count", AttributeValue.longAttributeValue(localAttemptSentMessages));
-    }
-    if (attemptReceivedMessages > 0) {
-      attributes.put(
-          "attempt response count", AttributeValue.longAttributeValue(attemptReceivedMessages));
-    }
-
-    String localLastConnectionId = lastConnectionId;
-    if (localLastConnectionId != null) {
-      attributes.put("connection", AttributeValue.stringAttributeValue(localLastConnectionId));
-    }
-
-    return attributes;
-  }
-
-  private void populateAttemptNumber(Map<String, AttributeValue> attributes) {
-    attributes.put("attempt", AttributeValue.longAttributeValue(currentAttemptId));
-  }
-
-  private void populateError(Map<String, AttributeValue> attributes, Throwable error) {
-    if (error == null) {
-      attributes.put("status", AttributeValue.stringAttributeValue("OK"));
-      return;
-    }
-
-    Status status = convertErrorToStatus(error);
-
-    attributes.put(
-        "status", AttributeValue.stringAttributeValue(status.getCanonicalCode().toString()));
-
-    if (!Strings.isNullOrEmpty(status.getDescription())) {
-      attributes.put(
-          "status message", AttributeValue.stringAttributeValue(status.getDescription()));
-    }
-  }
-
-  @InternalApi("Visible for testing")
-  static Status convertErrorToStatus(Throwable error) {
-    StatusCode.Code gaxCode = Code.UNKNOWN;
-
-    if (error instanceof ApiException) {
-      gaxCode = ((ApiException) error).getStatusCode().getCode();
-    } else if (error.getCause() instanceof ApiException) {
-      gaxCode = ((ApiException) error.getCause()).getStatusCode().getCode();
-    }
-
-    Status.CanonicalCode code;
-    try {
-      code = Status.CanonicalCode.valueOf(gaxCode.name());
-    } catch (IllegalArgumentException e) {
-      code = CanonicalCode.UNKNOWN;
-    }
-
-    return code.toStatus().withDescription(error.getMessage());
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracerFactory.java b/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracerFactory.java
deleted file mode 100644
index b9966b1f5..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/OpencensusTracerFactory.java
+++ /dev/null
@@ -1,135 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-import com.google.common.base.Objects;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Tracer;
-import io.opencensus.trace.Tracing;
-import java.util.Map;
-import javax.annotation.Nonnull;
-
-/**
- * A {@link ApiTracerFactory} to build instances of {@link OpencensusTracer}.
- *
- * <p>This class wraps the {@link Tracer} provided by Opencensus in {@code Tracing.getTracer()}. It
- * will be used to create new spans and wrap them in {@link OpencensusTracer} defined in gax.
- *
- * <p>This class is thread safe.
- */
-@InternalApi("For google-cloud-java client use only")
-public final class OpencensusTracerFactory extends BaseApiTracerFactory {
-  @Nonnull private final Tracer internalTracer;
-  @Nonnull private final Map<String, AttributeValue> spanAttributes;
-
-  /**
-   * Instantiates a new instance capturing the {@link io.opencensus.trace.Tracer} in {@code
-   * Tracing.getTracer}.
-   */
-  public OpencensusTracerFactory() {
-    this(ImmutableMap.<String, String>of());
-  }
-
-  /**
-   * Instantiates a new instance capturing the {@link io.opencensus.trace.Tracer} in {@code
-   * Tracing.getTracer}. It will also override the service name of the grpc stub with a custom
-   * client name. This is useful disambiguate spans created outer manual written wrappers and around
-   * generated gapic spans.
-   *
-   * @param spanAttributes the attributes to stamp on every span. Should include things like library
-   *     version.
-   */
-  public OpencensusTracerFactory(Map<String, String> spanAttributes) {
-    this(Tracing.getTracer(), spanAttributes);
-  }
-
-  /**
-   * Instantiates a new instance with an explicit {@link io.opencensus.trace.Tracer}. It will also
-   * override the service name of the grpc stub with a custom client name. This is useful
-   * disambiguate spans created outer manual written wrappers and around generated gapic spans.
-   *
-   * @param internalTracer the Opencensus tracer to wrap.
-   */
-  @InternalApi("Visible for testing")
-  OpencensusTracerFactory(Tracer internalTracer, @Nonnull Map<String, String> spanAttributes) {
-    this.internalTracer =
-        Preconditions.checkNotNull(internalTracer, "internalTracer can't be null");
-    ImmutableMap.Builder<String, AttributeValue> formattedSpanAttributes = ImmutableMap.builder();
-    for (Map.Entry<String, String> entry : spanAttributes.entrySet()) {
-      formattedSpanAttributes.put(
-          entry.getKey(), AttributeValue.stringAttributeValue(entry.getValue()));
-    }
-    this.spanAttributes = formattedSpanAttributes.build();
-  }
-
-  /** {@inheritDoc } */
-  @Override
-  public ApiTracer newTracer(ApiTracer parent, SpanName spanName, OperationType operationType) {
-    // Default to the current in context span. This is used for outermost tracers that inherit
-    // the caller's parent span.
-    Span parentSpan = internalTracer.getCurrentSpan();
-
-    // If an outer callable started a span, use it as the parent.
-    if (parent instanceof OpencensusTracer) {
-      parentSpan = ((OpencensusTracer) parent).getSpan();
-    }
-
-    Span span =
-        internalTracer
-            .spanBuilderWithExplicitParent(spanName.toString(), parentSpan)
-            .setRecordEvents(true)
-            .startSpan();
-    span.putAttributes(spanAttributes);
-
-    return new OpencensusTracer(internalTracer, span, operationType);
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-    OpencensusTracerFactory that = (OpencensusTracerFactory) o;
-    return Objects.equal(internalTracer, that.internalTracer)
-        && Objects.equal(spanAttributes, that.spanAttributes);
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hashCode(internalTracer, spanAttributes);
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/SpanName.java b/gax/src/main/java/com/google/api/gax/tracing/SpanName.java
deleted file mode 100644
index da62d7c5a..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/SpanName.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.auto.value.AutoValue;
-
-/** A value class to represent the name of the operation in an {@link ApiTracer}. */
-@BetaApi("Surface for tracing is not yet stable")
-@InternalApi("For google-cloud-java client use only")
-@AutoValue
-public abstract class SpanName {
-  /**
-   * Creates a new instance of the name.
-   *
-   * @param clientName The name of the client. In general this will be GAPIC generated client name.
-   *     However, in some cases, when the GAPIC generated client is wrapped, this will be overridden
-   *     to specify the manually written wrapper's name.
-   * @param methodName The name of the logical operation being traced.
-   */
-  public static SpanName of(String clientName, String methodName) {
-    return new AutoValue_SpanName(clientName, methodName);
-  }
-
-  /** The name of the client. ie BigtableData */
-  public abstract String getClientName();
-
-  /** The name of the logical operation being traced. ie. ReadRows. */
-  public abstract String getMethodName();
-
-  @Override
-  public String toString() {
-    return getClientName() + "." + getMethodName();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TraceFinisher.java b/gax/src/main/java/com/google/api/gax/tracing/TraceFinisher.java
deleted file mode 100644
index 292a82775..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TraceFinisher.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.ApiFutureCallback;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.CancellationException;
-import javax.annotation.Nonnull;
-
-/** An {@link ApiFutureCallback} to mark a started operation trace as finished. */
-class TraceFinisher<T> implements ApiFutureCallback<T> {
-  private final ApiTracer tracer;
-
-  TraceFinisher(@Nonnull ApiTracer tracer) {
-    this.tracer = Preconditions.checkNotNull(tracer, "tracer can't be null");
-  }
-
-  @Override
-  public void onFailure(Throwable throwable) {
-    if (throwable instanceof CancellationException) {
-      tracer.operationCancelled();
-    } else {
-      tracer.operationFailed(throwable);
-    }
-  }
-
-  @Override
-  public void onSuccess(T responseT) {
-    tracer.operationSucceeded();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedBatchingCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedBatchingCallable.java
deleted file mode 100644
index 0cfb7df08..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedBatchingCallable.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BatchingDescriptor;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.util.concurrent.MoreExecutors;
-
-/**
- * This callable wraps a batching callable chain in a {@link ApiTracer}.
- *
- * <p>For internal use only.
- */
-@BetaApi("The surface for tracing is not stable and might change in the future")
-@InternalApi("For internal use by google-cloud-java clients only")
-public class TracedBatchingCallable<RequestT, ResponseT>
-    extends UnaryCallable<RequestT, ResponseT> {
-  private final ApiTracerFactory tracerFactory;
-  private final SpanName spanName;
-  private final BatchingDescriptor<RequestT, ResponseT> batchingDescriptor;
-  private final UnaryCallable<RequestT, ResponseT> innerCallable;
-
-  public TracedBatchingCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      ApiTracerFactory tracerFactory,
-      SpanName spanName,
-      BatchingDescriptor<RequestT, ResponseT> batchingDescriptor) {
-    this.tracerFactory = tracerFactory;
-    this.spanName = spanName;
-    this.batchingDescriptor = batchingDescriptor;
-    this.innerCallable = innerCallable;
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-    // NOTE: This will be invoked asynchronously outside of the original caller's thread.
-    // So this start a top level tracer.
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.Batching);
-    TraceFinisher<ResponseT> finisher = new TraceFinisher<>(tracer);
-
-    try {
-      long elementCount = batchingDescriptor.countElements(request);
-      long requestSize = batchingDescriptor.countBytes(request);
-
-      tracer.batchRequestSent(elementCount, requestSize);
-
-      context = context.withTracer(tracer);
-      ApiFuture<ResponseT> future = innerCallable.futureCall(request, context);
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedBidiCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedBidiCallable.java
deleted file mode 100644
index fd2172752..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedBidiCallable.java
+++ /dev/null
@@ -1,154 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamReadyObserver;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.atomic.AtomicBoolean;
-import javax.annotation.Nonnull;
-
-/**
- * A wrapper callable that will wrap a callable chain in a trace.
- *
- * <p>For internal use only.
- */
-@BetaApi("The surface for tracing is not stable and might change in the future")
-@InternalApi("For internal use by google-cloud-java clients only")
-public class TracedBidiCallable<RequestT, ResponseT>
-    extends BidiStreamingCallable<RequestT, ResponseT> {
-
-  @Nonnull private final ApiTracerFactory tracerFactory;
-  @Nonnull private final SpanName spanName;
-  @Nonnull private final BidiStreamingCallable<RequestT, ResponseT> innerCallable;
-
-  public TracedBidiCallable(
-      @Nonnull BidiStreamingCallable<RequestT, ResponseT> innerCallable,
-      @Nonnull ApiTracerFactory tracerFactory,
-      @Nonnull SpanName spanName) {
-    this.tracerFactory = Preconditions.checkNotNull(tracerFactory, "tracerFactory can't be null");
-    this.spanName = Preconditions.checkNotNull(spanName, "spanName can't be null");
-    this.innerCallable = Preconditions.checkNotNull(innerCallable, "innerCallable can't be null");
-  }
-
-  @Override
-  public ClientStream<RequestT> internalCall(
-      ResponseObserver<ResponseT> responseObserver,
-      ClientStreamReadyObserver<RequestT> onReady,
-      ApiCallContext context) {
-
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.BidiStreaming);
-    context = context.withTracer(tracer);
-
-    AtomicBoolean wasCancelled = new AtomicBoolean();
-
-    ResponseObserver<ResponseT> tracedObserver =
-        new TracedResponseObserver<>(tracer, responseObserver, wasCancelled);
-    ClientStreamReadyObserver<RequestT> tracedReadyObserver =
-        new TracedClientStreamReadyObserver<>(tracer, onReady, wasCancelled);
-
-    try {
-      ClientStream<RequestT> clientStream =
-          innerCallable.internalCall(tracedObserver, tracedReadyObserver, context);
-      return new TracingClientStream<>(tracer, clientStream, wasCancelled);
-    } catch (RuntimeException e) {
-      tracer.operationFailed(e);
-      throw e;
-    }
-  }
-
-  private static class TracedClientStreamReadyObserver<RequestT>
-      implements ClientStreamReadyObserver<RequestT> {
-    private final ApiTracer tracer;
-    private final ClientStreamReadyObserver<RequestT> innerObserver;
-    private final AtomicBoolean wasCancelled;
-
-    TracedClientStreamReadyObserver(
-        ApiTracer tracer,
-        ClientStreamReadyObserver<RequestT> innerObserver,
-        AtomicBoolean wasCancelled) {
-      this.tracer = tracer;
-      this.innerObserver = innerObserver;
-      this.wasCancelled = wasCancelled;
-    }
-
-    @Override
-    public void onReady(ClientStream<RequestT> stream) {
-      innerObserver.onReady(new TracingClientStream<>(tracer, stream, wasCancelled));
-    }
-  }
-
-  /** {@link ClientStream} wrapper that annotates traces with sent messages. */
-  private static class TracingClientStream<RequestT> implements ClientStream<RequestT> {
-    private final ApiTracer tracer;
-    private final ClientStream<RequestT> innerStream;
-    private final AtomicBoolean wasCancelled;
-
-    private TracingClientStream(
-        ApiTracer tracer, ClientStream<RequestT> innerStream, AtomicBoolean wasCancelled) {
-      this.tracer = tracer;
-      this.innerStream = innerStream;
-      this.wasCancelled = wasCancelled;
-    }
-
-    @Override
-    public void send(RequestT request) {
-      tracer.requestSent();
-      innerStream.send(request);
-    }
-
-    @Override
-    public void closeSendWithError(Throwable t) {
-      if (t == null) {
-        t = new CancellationException();
-      }
-      wasCancelled.set(true);
-      innerStream.closeSendWithError(t);
-    }
-
-    @Override
-    public void closeSend() {
-      innerStream.closeSend();
-    }
-
-    @Override
-    public boolean isSendReady() {
-      return innerStream.isSendReady();
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedClientStreamingCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedClientStreamingCallable.java
deleted file mode 100644
index 773efe2de..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedClientStreamingCallable.java
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.atomic.AtomicReference;
-import javax.annotation.Nonnull;
-
-/**
- * A wrapper callable that will wrap a callable chain in a trace.
- *
- * <p>This can be safely called from multiple threads. However the request {@link ApiStreamObserver}
- * can only be used from a single thread.
- *
- * <p>For internal use only.
- */
-@BetaApi("The surface for tracing is not stable and might change in the future")
-@InternalApi
-public class TracedClientStreamingCallable<RequestT, ResponseT>
-    extends ClientStreamingCallable<RequestT, ResponseT> {
-  private final ClientStreamingCallable<RequestT, ResponseT> innerCallable;
-  private final ApiTracerFactory tracerFactory;
-  private final SpanName spanName;
-
-  public TracedClientStreamingCallable(
-      @Nonnull ClientStreamingCallable<RequestT, ResponseT> innerCallable,
-      @Nonnull ApiTracerFactory tracerFactory,
-      @Nonnull SpanName spanName) {
-    this.tracerFactory = Preconditions.checkNotNull(tracerFactory, "tracerFactory can't be null");
-    this.spanName = Preconditions.checkNotNull(spanName, "spanName can't be null");
-    this.innerCallable = Preconditions.checkNotNull(innerCallable, "innerCallable can't be null");
-  }
-
-  @Override
-  public ApiStreamObserver<RequestT> clientStreamingCall(
-      ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.ClientStreaming);
-    context = context.withTracer(tracer);
-
-    // Shared state that allows the response observer to know that the error it received was
-    // triggered by a caller initiated cancellation.
-    AtomicReference<Throwable> cancellationCauseHolder = new AtomicReference<>(null);
-
-    try {
-      ApiStreamObserver<ResponseT> innerResponseObserver =
-          new TracedResponseObserver<>(tracer, responseObserver, cancellationCauseHolder);
-
-      ApiStreamObserver<RequestT> innerRequestObserver =
-          innerCallable.clientStreamingCall(innerResponseObserver, context);
-
-      return new TracedRequestObserver<>(tracer, innerRequestObserver, cancellationCauseHolder);
-    } catch (RuntimeException e) {
-      tracer.operationFailed(e);
-      throw e;
-    }
-  }
-
-  /** {@link ApiStreamObserver} wrapper to annotate the current trace with sent message. */
-  private static class TracedRequestObserver<RequestT> implements ApiStreamObserver<RequestT> {
-    private final ApiTracer tracer;
-    private final ApiStreamObserver<RequestT> innerObserver;
-    private final AtomicReference<Throwable> cancellationCauseHolder;
-
-    TracedRequestObserver(
-        @Nonnull ApiTracer tracer,
-        @Nonnull ApiStreamObserver<RequestT> innerObserver,
-        @Nonnull AtomicReference<Throwable> cancellationCauseHolder) {
-      this.tracer = Preconditions.checkNotNull(tracer, "tracer can't be null");
-      this.innerObserver = Preconditions.checkNotNull(innerObserver, "innerObserver can't be null");
-      this.cancellationCauseHolder =
-          Preconditions.checkNotNull(
-              cancellationCauseHolder, "cancellationCauseHolder can't be null");
-    }
-
-    @Override
-    public void onNext(RequestT value) {
-      tracer.requestSent();
-      innerObserver.onNext(value);
-    }
-
-    @Override
-    public void onError(Throwable throwable) {
-      if (throwable == null) {
-        throwable = new CancellationException("Cancelled without a cause");
-      }
-      // NOTE: Calling onError will eventually cancel the entire stream. So we just set a flag now
-      // and trace later in the TracedResponseObserver.
-      cancellationCauseHolder.compareAndSet(null, throwable);
-      innerObserver.onError(throwable);
-    }
-
-    @Override
-    public void onCompleted() {
-      // TODO(igorbernstein2): consider tracing request stream completion.
-      innerObserver.onCompleted();
-    }
-  }
-
-  /**
-   * {@link ApiStreamObserver} wrapper to annotate the current trace with received messages and to
-   * close the current trace upon completion of the RPC.
-   */
-  private static class TracedResponseObserver<RequestT> implements ApiStreamObserver<RequestT> {
-    @Nonnull private final ApiTracer tracer;
-    @Nonnull private final ApiStreamObserver<RequestT> innerObserver;
-    @Nonnull private final AtomicReference<Throwable> cancellationCauseHolder;
-
-    TracedResponseObserver(
-        @Nonnull ApiTracer tracer,
-        @Nonnull ApiStreamObserver<RequestT> innerObserver,
-        @Nonnull AtomicReference<Throwable> cancellationCauseHolder) {
-      this.tracer = Preconditions.checkNotNull(tracer, "tracer can't be null");
-      this.innerObserver = Preconditions.checkNotNull(innerObserver, "innerObserver can't be null");
-      this.cancellationCauseHolder = cancellationCauseHolder;
-    }
-
-    @Override
-    public void onNext(RequestT value) {
-      tracer.responseReceived();
-      innerObserver.onNext(value);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      Throwable cancellationCause = cancellationCauseHolder.get();
-      if (cancellationCause != null) {
-        tracer.operationCancelled();
-      } else {
-        tracer.operationFailed(t);
-      }
-      innerObserver.onError(t);
-    }
-
-    @Override
-    public void onCompleted() {
-      tracer.operationSucceeded();
-      innerObserver.onCompleted();
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedOperationCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedOperationCallable.java
deleted file mode 100644
index 3b83d7fd7..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedOperationCallable.java
+++ /dev/null
@@ -1,132 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.util.concurrent.MoreExecutors;
-import javax.annotation.Nonnull;
-
-/**
- * This callable wraps a {@link OperationCallable} in a {@link ApiTracer}.
- *
- * <p>For internal use only.
- */
-@InternalApi("For internal use by google-cloud-java clients only")
-public class TracedOperationCallable<RequestT, ResponseT, MetadataT>
-    extends OperationCallable<RequestT, ResponseT, MetadataT> {
-
-  private @Nonnull OperationCallable<RequestT, ResponseT, MetadataT> innerCallable;
-  private @Nonnull ApiTracerFactory tracerFactory;
-  private @Nonnull SpanName spanName;
-
-  public TracedOperationCallable(
-      @Nonnull OperationCallable<RequestT, ResponseT, MetadataT> innerCallable,
-      @Nonnull ApiTracerFactory tracerFactory,
-      @Nonnull SpanName spanName) {
-    this.innerCallable = innerCallable;
-    this.tracerFactory = tracerFactory;
-    this.spanName = spanName;
-  }
-
-  /**
-   * Wrap the initial start polling logical operations in a single parent trace using a {@link
-   * OperationType#LongRunning} {@link ApiTracer}.
-   */
-  @Override
-  public OperationFuture<ResponseT, MetadataT> futureCall(
-      RequestT request, ApiCallContext context) {
-
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.LongRunning);
-    TraceFinisher<ResponseT> finisher = new TraceFinisher<>(tracer);
-
-    try {
-      context = context.withTracer(tracer);
-      OperationFuture<ResponseT, MetadataT> future = innerCallable.futureCall(request, context);
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-
-  /**
-   * Wrap the polling logical operations in a single parent trace using a {@link
-   * OperationType#LongRunning} {@link ApiTracer}.
-   */
-  @Override
-  public OperationFuture<ResponseT, MetadataT> resumeFutureCall(
-      String operationName, ApiCallContext context) {
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.LongRunning);
-    TraceFinisher<ResponseT> finisher = new TraceFinisher<>(tracer);
-
-    try {
-      context = context.withTracer(tracer);
-      OperationFuture<ResponseT, MetadataT> future =
-          innerCallable.resumeFutureCall(operationName, context);
-
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-
-  /** Wrap operation cancellation in a {@link OperationType#Unary} trace. */
-  @Override
-  public ApiFuture<Void> cancel(String operationName, ApiCallContext context) {
-    SpanName cancelSpanName =
-        SpanName.of(spanName.getClientName(), spanName.getMethodName() + ".Cancel");
-
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), cancelSpanName, OperationType.Unary);
-    TraceFinisher<Void> finisher = new TraceFinisher<>(tracer);
-
-    try {
-      context = context.withTracer(tracer);
-      ApiFuture<Void> future = innerCallable.cancel(operationName, context);
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedOperationInitialCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedOperationInitialCallable.java
deleted file mode 100644
index 224b8e0f1..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedOperationInitialCallable.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.util.concurrent.MoreExecutors;
-
-/**
- * Traces the initial RPC of a long running operation.
- *
- * <p>It will trace it like a child unary RPC and will also contribute to the parent tracer (created
- * by {@link TracedOperationCallable}) the result of the call.
- */
-public class TracedOperationInitialCallable<RequestT>
-    extends TracedUnaryCallable<RequestT, OperationSnapshot> {
-
-  public TracedOperationInitialCallable(
-      UnaryCallable<RequestT, OperationSnapshot> innerCallable,
-      ApiTracerFactory tracedFactory,
-      SpanName spanName) {
-    super(innerCallable, tracedFactory, spanName);
-  }
-
-  @Override
-  public ApiFuture<OperationSnapshot> futureCall(RequestT request, ApiCallContext context) {
-    InitialCallableFinisher finisher = new InitialCallableFinisher(context.getTracer());
-
-    try {
-      ApiFuture<OperationSnapshot> future = super.futureCall(request, context);
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-
-  private static class InitialCallableFinisher implements ApiFutureCallback<OperationSnapshot> {
-    private final ApiTracer operationTracer;
-
-    private InitialCallableFinisher(ApiTracer operationTracer) {
-      this.operationTracer = operationTracer;
-    }
-
-    @Override
-    public void onSuccess(OperationSnapshot result) {
-      operationTracer.lroStartSucceeded();
-    }
-
-    @Override
-    public void onFailure(Throwable t) {
-      operationTracer.lroStartFailed(t);
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedResponseObserver.java b/gax/src/main/java/com/google/api/gax/tracing/TracedResponseObserver.java
deleted file mode 100644
index ba72d2f5b..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedResponseObserver.java
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.atomic.AtomicBoolean;
-import javax.annotation.Nonnull;
-
-/**
- * A {@link ResponseObserver} to mark a started operation trace as finished.
- *
- * <p>The operation will be marked as complete before notifying the wrapped observer. Which means
- * that the span of the instrumentation will not include processing of the innerObserver's
- * onComplete.
- */
-@InternalApi
-class TracedResponseObserver<ResponseT> implements ResponseObserver<ResponseT> {
-  private final ApiTracer tracer;
-  private final ResponseObserver<ResponseT> innerObserver;
-  private AtomicBoolean wasCancelled;
-
-  TracedResponseObserver(
-      @Nonnull ApiTracer tracer, @Nonnull ResponseObserver<ResponseT> innerObserver) {
-    this(tracer, innerObserver, new AtomicBoolean());
-  }
-
-  TracedResponseObserver(
-      @Nonnull ApiTracer tracer,
-      @Nonnull ResponseObserver<ResponseT> innerObserver,
-      @Nonnull AtomicBoolean wasCancelled) {
-    this.tracer = Preconditions.checkNotNull(tracer, "tracer");
-    this.innerObserver = Preconditions.checkNotNull(innerObserver, "innerObserver");
-    this.wasCancelled = Preconditions.checkNotNull(wasCancelled, "wasCancelled");
-  }
-
-  @Override
-  public void onStart(final StreamController controller) {
-    innerObserver.onStart(
-        new StreamController() {
-          @Override
-          public void cancel() {
-            wasCancelled.set(true);
-            controller.cancel();
-          }
-
-          @Override
-          public void disableAutoInboundFlowControl() {
-            controller.disableAutoInboundFlowControl();
-          }
-
-          @Override
-          public void request(int count) {
-            controller.request(count);
-          }
-        });
-  }
-
-  @Override
-  public void onResponse(ResponseT response) {
-    tracer.responseReceived();
-    innerObserver.onResponse(response);
-  }
-
-  @Override
-  public void onError(Throwable t) {
-    // Only mark explicit user cancellations. Since the retry logic can also throw
-    // CancellationException, we can't simply check that t is an instance of a
-    // CancellationException.
-    if (wasCancelled.get()) {
-      tracer.operationCancelled();
-    } else {
-      tracer.operationFailed(t);
-    }
-    innerObserver.onError(t);
-  }
-
-  @Override
-  public void onComplete() {
-    tracer.operationSucceeded();
-    innerObserver.onComplete();
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedServerStreamingCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedServerStreamingCallable.java
deleted file mode 100644
index e46520e61..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedServerStreamingCallable.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.base.Preconditions;
-import javax.annotation.Nonnull;
-
-/**
- * A wrapper callable that will wrap a callable chain in a trace.
- *
- * <p>For internal use only.
- */
-@BetaApi("The surface for tracing is not stable and might change in the future")
-@InternalApi("For internal use by google-cloud-java clients only")
-public final class TracedServerStreamingCallable<RequestT, ResponseT>
-    extends ServerStreamingCallable<RequestT, ResponseT> {
-
-  @Nonnull private final ApiTracerFactory tracerFactory;
-  @Nonnull private final SpanName spanName;
-  @Nonnull private final ServerStreamingCallable<RequestT, ResponseT> innerCallable;
-
-  public TracedServerStreamingCallable(
-      @Nonnull ServerStreamingCallable<RequestT, ResponseT> innerCallable,
-      @Nonnull ApiTracerFactory tracerFactory,
-      @Nonnull SpanName spanName) {
-    this.tracerFactory = Preconditions.checkNotNull(tracerFactory, "tracerFactory can't be null");
-    this.spanName = Preconditions.checkNotNull(spanName, "spanName can't be null");
-    this.innerCallable = Preconditions.checkNotNull(innerCallable, "innerCallable can't be null");
-  }
-
-  @Override
-  public void call(
-      RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-
-    ApiTracer tracer =
-        tracerFactory.newTracer(context.getTracer(), spanName, OperationType.ServerStreaming);
-    TracedResponseObserver<ResponseT> tracedObserver =
-        new TracedResponseObserver<>(tracer, responseObserver);
-
-    context = context.withTracer(tracer);
-
-    try {
-      innerCallable.call(request, tracedObserver, context);
-    } catch (RuntimeException e) {
-      tracedObserver.onError(e);
-      throw e;
-    }
-  }
-}
diff --git a/gax/src/main/java/com/google/api/gax/tracing/TracedUnaryCallable.java b/gax/src/main/java/com/google/api/gax/tracing/TracedUnaryCallable.java
deleted file mode 100644
index b7d628dcf..000000000
--- a/gax/src/main/java/com/google/api/gax/tracing/TracedUnaryCallable.java
+++ /dev/null
@@ -1,84 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.util.concurrent.MoreExecutors;
-
-/**
- * This callable wraps a callable chain in a {@link ApiTracer}.
- *
- * <p>For internal use only.
- */
-@BetaApi("The surface for tracing is not stable and might change in the future")
-@InternalApi("For internal use by google-cloud-java clients only")
-public class TracedUnaryCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> innerCallable;
-  private final ApiTracerFactory tracerFactory;
-  private final SpanName spanName;
-
-  public TracedUnaryCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      ApiTracerFactory tracerFactory,
-      SpanName spanName) {
-    this.innerCallable = innerCallable;
-    this.tracerFactory = tracerFactory;
-    this.spanName = spanName;
-  }
-
-  /**
-   * Calls the wrapped {@link UnaryCallable} within the context of a new trace.
-   *
-   * @param request the request to send.
-   * @param context {@link ApiCallContext} to make the call with.
-   */
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-    ApiTracer tracer = tracerFactory.newTracer(context.getTracer(), spanName, OperationType.Unary);
-    TraceFinisher<ResponseT> finisher = new TraceFinisher<>(tracer);
-
-    try {
-      context = context.withTracer(tracer);
-      ApiFuture<ResponseT> future = innerCallable.futureCall(request, context);
-      ApiFutures.addCallback(future, finisher, MoreExecutors.directExecutor());
-
-      return future;
-    } catch (RuntimeException e) {
-      finisher.onFailure(e);
-      throw e;
-    }
-  }
-}
diff --git a/gax/src/main/resources/META-INF/native-image/com.google.api/gax/native-image.properties b/gax/src/main/resources/META-INF/native-image/com.google.api/gax/native-image.properties
deleted file mode 100644
index d411aa2e5..000000000
--- a/gax/src/main/resources/META-INF/native-image/com.google.api/gax/native-image.properties
+++ /dev/null
@@ -1,8 +0,0 @@
-Args = --enable-url-protocols=https,http \
---initialize-at-build-time=org.conscrypt,\
-  org.slf4j.LoggerFactory,\
-  org.junit.platform.engine.TestTag \
---initialize-at-run-time=com.google.api.client.googleapis.services.AbstractGoogleClientRequest$ApiClientVersion \
-  --features=com.google.api.gax.nativeimage.OpenCensusFeature,\
-  com.google.api.gax.nativeimage.GoogleJsonClientFeature \
-  --add-modules=jdk.httpserver
diff --git a/gax/src/main/resources/META-INF/native-image/com.google.api/gax/resource-config.json b/gax/src/main/resources/META-INF/native-image/com.google.api/gax/resource-config.json
deleted file mode 100644
index bc40a95d5..000000000
--- a/gax/src/main/resources/META-INF/native-image/com.google.api/gax/resource-config.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "resources":[
-    {"pattern":"\\QMETA-INF/services/jdk.vm.ci.services.JVMCIServiceLocator\\E"},
-    {"pattern":"\\Qdependencies.properties\\E"},
-    {"pattern":"\\Qcom/google/api/client/googleapis/google-api-client.properties\\E"},
-    {"pattern":"\\Qcom/google/api/client/googleapis/google.p12\\E"},
-    {"pattern":"\\Qcom/google/api/client/http/google-http-client.properties\\E"}],
-  "bundles":[]
-}
diff --git a/gax/src/main/resources/dependencies.properties b/gax/src/main/resources/dependencies.properties
deleted file mode 100644
index 60e15975f..000000000
--- a/gax/src/main/resources/dependencies.properties
+++ /dev/null
@@ -1,2 +0,0 @@
-# Used in GaxProperties to determine the version of the project
-version.gax=${project.version}
\ No newline at end of file
diff --git a/gax/src/test/java/com/google/api/gax/batching/BatcherImplTest.java b/gax/src/test/java/com/google/api/gax/batching/BatcherImplTest.java
deleted file mode 100644
index b503e28da..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/BatcherImplTest.java
+++ /dev/null
@@ -1,956 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.SQUARER_BATCHING_DESC_V2;
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.callLabeledIntSquarer;
-import static com.google.common.truth.Truth.assertThat;
-import static com.google.common.truth.Truth.assertWithMessage;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.batching.BatcherImpl.BatcherReference;
-import com.google.api.gax.batching.FlowController.FlowControlRuntimeException;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntSquarerCallable;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.SquarerBatchingDescriptorV2;
-import com.google.common.base.Stopwatch;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Queues;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.logging.Filter;
-import java.util.logging.Level;
-import java.util.logging.LogRecord;
-import java.util.logging.Logger;
-import org.junit.After;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.function.ThrowingRunnable;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatcherImplTest {
-
-  private static final ScheduledExecutorService EXECUTOR =
-      Executors.newSingleThreadScheduledExecutor();
-
-  private Batcher<Integer, Integer> underTest;
-  private final LabeledIntList labeledIntList = new LabeledIntList("Default");
-  private final BatchingSettings batchingSettings =
-      BatchingSettings.newBuilder()
-          .setElementCountThreshold(1000L)
-          .setRequestByteThreshold(1000L)
-          .setDelayThreshold(Duration.ofSeconds(1))
-          .build();
-
-  @After
-  public void tearDown() throws InterruptedException {
-    if (underTest != null) {
-      try {
-        // Close the batcher to avoid warnings of orphaned batchers
-        underTest.close();
-      } catch (BatchingException ignored) {
-        // Some tests intentionally inject failures into mutations
-      }
-    }
-  }
-
-  @AfterClass
-  public static void tearDownExecutor() throws InterruptedException {
-    EXECUTOR.shutdown();
-    EXECUTOR.awaitTermination(100, TimeUnit.MILLISECONDS);
-  }
-  /** The accumulated results in the test are resolved when {@link Batcher#flush()} is called. */
-  @Test
-  public void testResultsAreResolvedAfterFlush() throws Exception {
-    underTest = createDefaultBatcherImpl(batchingSettings, null);
-    Future<Integer> result = underTest.add(4);
-    assertThat(result.isDone()).isFalse();
-    underTest.flush();
-    assertThat(result.isDone()).isTrue();
-    assertThat(result.get()).isEqualTo(16);
-
-    Future<Integer> anotherResult = underTest.add(5);
-    assertThat(anotherResult.isDone()).isFalse();
-  }
-
-  @Test
-  public void testSendOutstanding() {
-    final AtomicInteger callableCounter = new AtomicInteger();
-
-    underTest =
-        new BatcherImpl<>(
-            SQUARER_BATCHING_DESC_V2,
-            new LabeledIntSquarerCallable() {
-              @Override
-              public ApiFuture<List<Integer>> futureCall(
-                  LabeledIntList request, ApiCallContext context) {
-                callableCounter.incrementAndGet();
-                return super.futureCall(request, context);
-              }
-            },
-            labeledIntList,
-            batchingSettings,
-            EXECUTOR);
-
-    // Empty Batcher
-    underTest.sendOutstanding();
-    assertThat(callableCounter.get()).isEqualTo(0);
-
-    underTest.add(2);
-    underTest.add(3);
-    underTest.add(4);
-    underTest.sendOutstanding();
-    assertThat(callableCounter.get()).isEqualTo(1);
-  }
-
-  /** Element results are resolved after batch is closed. */
-  @Test
-  public void testWhenBatcherIsClose() throws Exception {
-    Future<Integer> result;
-    try (Batcher<Integer, Integer> batcher = createDefaultBatcherImpl(batchingSettings, null)) {
-      result = batcher.add(5);
-    }
-    assertThat(result.isDone()).isTrue();
-    assertThat(result.get()).isEqualTo(25);
-  }
-
-  /** Validates exception when batch is called after {@link Batcher#close()}. */
-  @Test
-  public void testNoElementAdditionAfterClose() throws Exception {
-    underTest = createDefaultBatcherImpl(batchingSettings, null);
-    underTest.close();
-    Throwable addOnClosedError = null;
-    try {
-      underTest.add(1);
-    } catch (Exception ex) {
-      addOnClosedError = ex;
-    }
-    assertThat(addOnClosedError).isInstanceOf(IllegalStateException.class);
-    assertThat(addOnClosedError)
-        .hasMessageThat()
-        .matches("Cannot add elements on a closed batcher");
-  }
-
-  /** Validates exception when batch is called after {@link Batcher#close()}. */
-  @Test
-  public void testNoElementAdditionAfterCloseAsync() throws Exception {
-    underTest = createDefaultBatcherImpl(batchingSettings, null);
-    underTest.add(1);
-    underTest.closeAsync();
-
-    IllegalStateException e =
-        Assert.assertThrows(
-            IllegalStateException.class,
-            new ThrowingRunnable() {
-              @Override
-              public void run() throws Throwable {
-                underTest.add(1);
-              }
-            });
-
-    assertThat(e).hasMessageThat().matches("Cannot add elements on a closed batcher");
-  }
-
-  @Test
-  public void testCloseAsyncNonblocking() throws ExecutionException, InterruptedException {
-    final SettableApiFuture<List<Integer>> innerFuture = SettableApiFuture.create();
-
-    UnaryCallable<LabeledIntList, List<Integer>> unaryCallable =
-        new UnaryCallable<LabeledIntList, List<Integer>>() {
-          @Override
-          public ApiFuture<List<Integer>> futureCall(
-              LabeledIntList request, ApiCallContext context) {
-            return innerFuture;
-          }
-        };
-    underTest =
-        new BatcherImpl<>(
-            SQUARER_BATCHING_DESC_V2, unaryCallable, labeledIntList, batchingSettings, EXECUTOR);
-
-    ApiFuture<Integer> elementFuture = underTest.add(1);
-
-    Stopwatch stopwatch = Stopwatch.createStarted();
-    ApiFuture<Void> closeFuture = underTest.closeAsync();
-    assertThat(stopwatch.elapsed(TimeUnit.MILLISECONDS)).isAtMost(100);
-
-    assertThat(closeFuture.isDone()).isFalse();
-    assertThat(elementFuture.isDone()).isFalse();
-
-    innerFuture.set(ImmutableList.of(1));
-    closeFuture.get();
-  }
-
-  /** Verifies exception occurred at RPC is propagated to element results */
-  @Test
-  public void testResultFailureAfterRPCFailure() throws Exception {
-    final Exception fakeError = new RuntimeException();
-    UnaryCallable<LabeledIntList, List<Integer>> unaryCallable =
-        new UnaryCallable<LabeledIntList, List<Integer>>() {
-          @Override
-          public ApiFuture<List<Integer>> futureCall(
-              LabeledIntList request, ApiCallContext context) {
-            return ApiFutures.immediateFailedFuture(fakeError);
-          }
-        };
-    underTest =
-        new BatcherImpl<>(
-            SQUARER_BATCHING_DESC_V2, unaryCallable, labeledIntList, batchingSettings, EXECUTOR);
-    Future<Integer> failedResult = underTest.add(5);
-    underTest.add(6);
-    underTest.add(7);
-    underTest.flush();
-    assertThat(failedResult.isDone()).isTrue();
-    Throwable actualError = null;
-    try {
-      failedResult.get();
-    } catch (InterruptedException | ExecutionException ex) {
-      actualError = ex;
-    }
-    assertThat(actualError).hasCauseThat().isSameInstanceAs(fakeError);
-
-    try {
-      underTest.close();
-    } catch (RuntimeException e) {
-      actualError = e;
-    }
-
-    assertThat(actualError).isNotNull();
-    assertThat(actualError).isInstanceOf(BatchingException.class);
-    assertThat(actualError)
-        .hasMessageThat()
-        .contains("1 batches failed to apply due to: 1 RuntimeException");
-  }
-
-  /** Resolves future results when {@link BatchingDescriptor#splitResponse} throws exception. */
-  @Test
-  public void testExceptionInDescriptor() throws InterruptedException {
-    final RuntimeException fakeError = new RuntimeException("internal exception");
-    BatchingDescriptor<Integer, Integer, LabeledIntList, List<Integer>> descriptor =
-        new SquarerBatchingDescriptorV2() {
-          @Override
-          public void splitResponse(
-              List<Integer> batchResponse, List<BatchEntry<Integer, Integer>> batch) {
-            throw fakeError;
-          }
-        };
-    underTest =
-        new BatcherImpl<>(
-            descriptor, callLabeledIntSquarer, labeledIntList, batchingSettings, EXECUTOR);
-
-    Future<Integer> result = underTest.add(2);
-    underTest.flush();
-    Throwable actualError = null;
-    try {
-      result.get();
-    } catch (ExecutionException ex) {
-      actualError = ex;
-    }
-
-    assertThat(actualError).hasCauseThat().isSameInstanceAs(fakeError);
-    try {
-      underTest.close();
-    } catch (Exception batchingEx) {
-      actualError = batchingEx;
-    }
-    assertThat(actualError).isInstanceOf(BatchingException.class);
-    assertThat(actualError)
-        .hasMessageThat()
-        .contains(
-            "Batching finished with 1 batches failed to apply due to: 1 RuntimeException and 0 "
-                + "partial failures.");
-  }
-
-  /** Resolves future results when {@link BatchingDescriptor#splitException} throws exception */
-  @Test
-  public void testExceptionInDescriptorErrorHandling() throws InterruptedException {
-    final RuntimeException fakeError = new RuntimeException("internal exception");
-    BatchingDescriptor<Integer, Integer, LabeledIntList, List<Integer>> descriptor =
-        new SquarerBatchingDescriptorV2() {
-          @Override
-          public void splitResponse(
-              List<Integer> batchResponse, List<BatchEntry<Integer, Integer>> batch) {
-            throw fakeError;
-          }
-
-          @Override
-          public void splitException(
-              Throwable throwable, List<BatchEntry<Integer, Integer>> batch) {
-            throw fakeError;
-          }
-        };
-    underTest =
-        new BatcherImpl<>(
-            descriptor, callLabeledIntSquarer, labeledIntList, batchingSettings, EXECUTOR);
-
-    Future<Integer> result = underTest.add(2);
-    underTest.flush();
-    Throwable actualError = null;
-    try {
-      result.get();
-    } catch (ExecutionException ex) {
-      actualError = ex;
-    }
-
-    assertThat(actualError).hasCauseThat().isSameInstanceAs(fakeError);
-    try {
-      underTest.close();
-    } catch (Exception ex) {
-      actualError = ex;
-    }
-    assertThat(actualError).isInstanceOf(BatchingException.class);
-  }
-
-  @Test
-  public void testWhenElementCountExceeds() throws Exception {
-    BatchingSettings settings = batchingSettings.toBuilder().setElementCountThreshold(2L).build();
-    testElementTriggers(settings);
-  }
-
-  @Test
-  public void testWhenElementBytesExceeds() throws Exception {
-    BatchingSettings settings = batchingSettings.toBuilder().setRequestByteThreshold(2L).build();
-    testElementTriggers(settings);
-  }
-
-  @Test
-  public void testWhenThresholdIsDisabled() throws Exception {
-    BatchingSettings settings =
-        BatchingSettings.newBuilder()
-            .setElementCountThreshold(null)
-            .setRequestByteThreshold(null)
-            .setDelayThreshold(null)
-            .build();
-    underTest = createDefaultBatcherImpl(settings, null);
-    Future<Integer> result = underTest.add(2);
-    assertThat(result.isDone()).isTrue();
-    assertThat(result.get()).isEqualTo(4);
-  }
-
-  @Test
-  public void testWhenDelayThresholdExceeds() throws Exception {
-    BatchingSettings settings =
-        batchingSettings.toBuilder().setDelayThreshold(Duration.ofMillis(100)).build();
-    underTest = createDefaultBatcherImpl(settings, null);
-    Future<Integer> result = underTest.add(6);
-    assertThat(result.isDone()).isFalse();
-    assertThat(result.get()).isEqualTo(36);
-  }
-
-  /** Validates that the elements are not leaking to multiple batches */
-  @Test(timeout = 500)
-  public void testElementsNotLeaking() throws Exception {
-    ExecutorService singleThreadExecutor = Executors.newSingleThreadExecutor();
-    ScheduledExecutorService multiThreadExecutor = Executors.newScheduledThreadPool(20);
-
-    final AtomicBoolean isDuplicateElement = new AtomicBoolean(false);
-    final ConcurrentMap<Integer, Boolean> map = new ConcurrentHashMap<>();
-    final UnaryCallable<LabeledIntList, List<Integer>> callable =
-        new UnaryCallable<LabeledIntList, List<Integer>>() {
-          @Override
-          public ApiFuture<List<Integer>> futureCall(
-              LabeledIntList request, ApiCallContext context) {
-            for (int val : request.ints) {
-              Boolean isPresent = map.putIfAbsent(val, Boolean.TRUE);
-              if (isPresent != null && isPresent) {
-                isDuplicateElement.set(true);
-                throw new AssertionError("Duplicate Element found");
-              }
-            }
-            return ApiFutures.immediateFuture(request.ints);
-          }
-        };
-    BatchingSettings settings =
-        batchingSettings.toBuilder().setDelayThreshold(Duration.ofMillis(50)).build();
-
-    try (final BatcherImpl<Integer, Integer, LabeledIntList, List<Integer>> batcherTest =
-        new BatcherImpl<>(SQUARER_BATCHING_DESC_V2, callable, labeledIntList, settings, EXECUTOR)) {
-
-      final Callable<Void> addElement =
-          new Callable<Void>() {
-            @Override
-            public Void call() throws Exception {
-              int counter = 0;
-              while (!isDuplicateElement.get() && counter < 10_000) {
-                batcherTest.add(counter++);
-              }
-              return null;
-            }
-          };
-      final Callable<Void> sendBatch =
-          new Callable<Void>() {
-            @Override
-            public Void call() throws InterruptedException {
-              batcherTest.flush();
-              return null;
-            }
-          };
-
-      // Started sequential element addition
-      Future<Void> future = singleThreadExecutor.submit(addElement);
-      for (int i = 0; !isDuplicateElement.get() && i < 3_000; i++) {
-        multiThreadExecutor.submit(sendBatch);
-      }
-
-      // Closing the resources
-      future.get();
-      assertThat(isDuplicateElement.get()).isFalse();
-      singleThreadExecutor.shutdown();
-      multiThreadExecutor.shutdown();
-    }
-  }
-
-  /** Validates ongoing runnable is cancelled once Batcher is GCed. */
-  @Test
-  public void testPushCurrentBatchRunnable() throws Exception {
-    long DELAY_TIME = 50L;
-    BatchingSettings settings =
-        batchingSettings.toBuilder().setDelayThreshold(Duration.ofMillis(DELAY_TIME)).build();
-    BatcherImpl<Integer, Integer, LabeledIntList, List<Integer>> batcher =
-        createDefaultBatcherImpl(settings, null);
-
-    BatcherImpl.PushCurrentBatchRunnable<Integer, Integer, LabeledIntList, List<Integer>>
-        pushBatchRunnable = new BatcherImpl.PushCurrentBatchRunnable<>(batcher);
-    ScheduledFuture<?> onGoingRunnable =
-        EXECUTOR.scheduleWithFixedDelay(
-            pushBatchRunnable, DELAY_TIME, DELAY_TIME, TimeUnit.MILLISECONDS);
-    pushBatchRunnable.setScheduledFuture(onGoingRunnable);
-
-    boolean isExecutorCancelled = pushBatchRunnable.isCancelled();
-
-    // ScheduledFuture should be not isCancelled yet.
-    assertThat(isExecutorCancelled).isFalse();
-
-    // Batcher present inside runnable should be GCed after following loop.
-    batcher.close();
-    batcher = null;
-    for (int retry = 0; retry < 3; retry++) {
-      System.gc();
-      System.runFinalization();
-      isExecutorCancelled = pushBatchRunnable.isCancelled();
-      if (isExecutorCancelled) {
-        break;
-      }
-      Thread.sleep(DELAY_TIME * (1L << retry));
-    }
-    // ScheduledFuture should be isCancelled now.
-    assertThat(pushBatchRunnable.isCancelled()).isTrue();
-  }
-
-  @Test
-  public void testEmptyBatchesAreNeverSent() throws Exception {
-    UnaryCallable<LabeledIntList, List<Integer>> callable =
-        new UnaryCallable<LabeledIntList, List<Integer>>() {
-          @Override
-          public ApiFuture<List<Integer>> futureCall(
-              LabeledIntList request, ApiCallContext context) {
-            throw new AssertionError("Should not call");
-          }
-        };
-    underTest =
-        new BatcherImpl<>(
-            SQUARER_BATCHING_DESC_V2, callable, labeledIntList, batchingSettings, EXECUTOR);
-    underTest.flush();
-  }
-
-  /** To confirm the partial failures in Batching does not mark whole batch failed */
-  @Test
-  public void testPartialFailureWithSplitResponse() throws Exception {
-    SquarerBatchingDescriptorV2 descriptor =
-        new SquarerBatchingDescriptorV2() {
-          @Override
-          public void splitResponse(
-              List<Integer> batchResponse, List<BatchEntry<Integer, Integer>> batch) {
-            for (int i = 0; i < batchResponse.size(); i++) {
-              if (batchResponse.get(i) > 10_000) {
-                batch.get(i).getResultFuture().setException(new ArithmeticException());
-              } else {
-                batch.get(i).getResultFuture().set(batchResponse.get(i));
-              }
-            }
-          }
-        };
-
-    underTest =
-        new BatcherImpl<>(
-            descriptor, callLabeledIntSquarer, labeledIntList, batchingSettings, EXECUTOR);
-    underTest.add(10);
-    // This will cause partial failure
-    underTest.add(200);
-    underTest.flush();
-
-    underTest.add(40);
-    underTest.add(50);
-    underTest.flush();
-
-    // These will cause partial failure
-    underTest.add(500);
-    underTest.add(600);
-    Exception actualError = null;
-    try {
-      underTest.close();
-    } catch (Exception e) {
-      actualError = e;
-    }
-    assertThat(actualError).isInstanceOf(BatchingException.class);
-    assertThat(actualError)
-        .hasMessageThat()
-        .contains(
-            "Batching finished with 2 partial failures. The 2 partial failures contained "
-                + "3 entries that failed with: 3 ArithmeticException.");
-  }
-
-  @Test
-  public void testPartialFailureInResultProcessing() throws Exception {
-    final Queue<RuntimeException> queue = Queues.newArrayBlockingQueue(3);
-    queue.add(new NullPointerException());
-    queue.add(new RuntimeException());
-    queue.add(new ArithmeticException());
-
-    SquarerBatchingDescriptorV2 descriptor =
-        new SquarerBatchingDescriptorV2() {
-
-          @Override
-          public void splitResponse(
-              List<Integer> batchResponse, List<BatchEntry<Integer, Integer>> batch) {
-            throw queue.poll();
-          }
-        };
-
-    underTest =
-        new BatcherImpl<>(
-            descriptor, callLabeledIntSquarer, labeledIntList, batchingSettings, EXECUTOR);
-    // This batch should fail with NullPointerException
-    underTest.add(10);
-    underTest.flush();
-
-    // This batch should fail with RuntimeException
-    underTest.add(20);
-    underTest.add(30);
-    underTest.flush();
-
-    // This batch should fail with ArithmeticException
-    underTest.add(40);
-    underTest.add(50);
-    underTest.add(60);
-
-    Exception actualError = null;
-    try {
-      underTest.close();
-    } catch (Exception e) {
-      actualError = e;
-    }
-    assertThat(actualError).isInstanceOf(BatchingException.class);
-    assertThat(actualError)
-        .hasMessageThat()
-        .contains("Batching finished with 3 batches failed to apply due to:");
-    assertThat(actualError).hasMessageThat().contains("1 NullPointerException");
-    assertThat(actualError).hasMessageThat().contains("1 RuntimeException");
-    assertThat(actualError).hasMessageThat().contains("1 ArithmeticException");
-    assertThat(actualError).hasMessageThat().contains(" and 0 partial failures.");
-  }
-
-  /**
-   * Validates the presence of warning in case {@link BatcherImpl} is garbage collected without
-   * being closed first.
-   *
-   * <p>Note:This test cannot run concurrently with other tests that use Batchers.
-   */
-  @Test
-  public void testUnclosedBatchersAreLogged() throws Exception {
-    final long DELAY_TIME = 30L;
-    int actualRemaining = 0;
-    for (int retry = 0; retry < 3; retry++) {
-      System.gc();
-      System.runFinalization();
-      actualRemaining = BatcherReference.cleanQueue();
-      if (actualRemaining == 0) {
-        break;
-      }
-      Thread.sleep(DELAY_TIME * (1L << retry));
-    }
-    assertThat(actualRemaining).isAtMost(0);
-    underTest = createDefaultBatcherImpl(batchingSettings, null);
-    Batcher<Integer, Integer> extraBatcher = createDefaultBatcherImpl(batchingSettings, null);
-
-    // Try to capture the log output but without causing terminal noise.  Adding the filter must
-    // be done before clearing the ref or else it might be missed.
-    final List<LogRecord> records = new ArrayList<>(1);
-    Logger batcherLogger = Logger.getLogger(BatcherImpl.class.getName());
-    Filter oldFilter = batcherLogger.getFilter();
-    batcherLogger.setFilter(
-        new Filter() {
-          @Override
-          public boolean isLoggable(LogRecord record) {
-            synchronized (records) {
-              records.add(record);
-            }
-            return false;
-          }
-        });
-
-    try {
-      // extraBatcher should not create any noise in the console as we called close() on it.
-      extraBatcher.close();
-      extraBatcher = null;
-
-      underTest = null;
-      // That *should* have been the last reference.  Try to reclaim it.
-      boolean success = false;
-      for (int retry = 0; retry < 3; retry++) {
-        System.gc();
-        System.runFinalization();
-        int orphans = BatcherReference.cleanQueue();
-        if (orphans == 1) {
-          success = true;
-          break;
-        }
-        // Validates that there are no other batcher instance present while GC cleanup.
-        assertWithMessage("unexpected extra orphans").that(orphans).isEqualTo(0);
-        Thread.sleep(DELAY_TIME * (1L << retry));
-      }
-      assertWithMessage("Batcher was not garbage collected").that(success).isTrue();
-
-      LogRecord lr;
-      synchronized (records) {
-        assertThat(records.size()).isEqualTo(1);
-        lr = records.get(0);
-      }
-      assertThat(lr.getMessage()).contains("not closed properly");
-      assertThat(lr.getLevel()).isEqualTo(Level.SEVERE);
-    } finally {
-      batcherLogger.setFilter(oldFilter);
-    }
-  }
-
-  /**
-   * Validates the absence of warning in case {@link BatcherImpl} is garbage collected after being
-   * closed.
-   *
-   * <p>Note:This test cannot run concurrently with other tests that use Batchers.
-   */
-  @Test
-  public void testClosedBatchersAreNotLogged() throws Exception {
-    // Clean out the existing instances
-    final long DELAY_TIME = 30L;
-    int actualRemaining = 0;
-    for (int retry = 0; retry < 3; retry++) {
-      System.gc();
-      System.runFinalization();
-      actualRemaining = BatcherReference.cleanQueue();
-      if (actualRemaining == 0) {
-        break;
-      }
-      Thread.sleep(DELAY_TIME * (1L << retry));
-    }
-    assertThat(actualRemaining).isAtMost(0);
-
-    // Capture logs
-    final List<LogRecord> records = new ArrayList<>(1);
-    Logger batcherLogger = Logger.getLogger(BatcherImpl.class.getName());
-    Filter oldFilter = batcherLogger.getFilter();
-    batcherLogger.setFilter(
-        new Filter() {
-          @Override
-          public boolean isLoggable(LogRecord record) {
-            synchronized (records) {
-              records.add(record);
-            }
-            return false;
-          }
-        });
-
-    try {
-      // Create a bunch of batchers that will garbage collected after being closed
-      for (int i = 0; i < 1_000; i++) {
-        BatcherImpl<Integer, Integer, LabeledIntList, List<Integer>> batcher =
-            createDefaultBatcherImpl(batchingSettings, null);
-        batcher.add(1);
-
-        if (i % 2 == 0) {
-          batcher.close();
-        } else {
-          batcher.closeAsync();
-        }
-      }
-      // Run GC a few times to give the batchers a chance to be collected
-      for (int retry = 0; retry < 100; retry++) {
-        System.gc();
-        System.runFinalization();
-        BatcherReference.cleanQueue();
-        Thread.sleep(10);
-      }
-
-      synchronized (records) {
-        assertThat(records).isEmpty();
-      }
-    } finally {
-      // reset logging
-      batcherLogger.setFilter(oldFilter);
-    }
-  }
-
-  @Test
-  public void testCloseRace() throws ExecutionException, InterruptedException, TimeoutException {
-    int iterations = 1_000_000;
-    ExecutorService executor = Executors.newFixedThreadPool(100);
-
-    try {
-      List<Future<?>> closeFutures = new ArrayList<>();
-
-      for (int i = 0; i < iterations; i++) {
-        final SettableApiFuture<List<Integer>> result = SettableApiFuture.create();
-
-        UnaryCallable<LabeledIntList, List<Integer>> callable =
-            new UnaryCallable<LabeledIntList, List<Integer>>() {
-              @Override
-              public ApiFuture<List<Integer>> futureCall(
-                  LabeledIntList request, ApiCallContext context) {
-                return result;
-              }
-            };
-        final Batcher<Integer, Integer> batcher =
-            new BatcherImpl<>(
-                SQUARER_BATCHING_DESC_V2, callable, labeledIntList, batchingSettings, EXECUTOR);
-
-        batcher.add(1);
-
-        executor.execute(
-            new Runnable() {
-              @Override
-              public void run() {
-                result.set(ImmutableList.of(1));
-              }
-            });
-        Future<?> f =
-            executor.submit(
-                new Runnable() {
-                  @Override
-                  public void run() {
-                    try {
-                      batcher.close();
-                    } catch (InterruptedException e) {
-                      Thread.currentThread().interrupt();
-                      throw new RuntimeException(e);
-                    }
-                  }
-                });
-
-        closeFutures.add(f);
-      }
-
-      // Make sure that none hang
-      for (Future<?> f : closeFutures) {
-        try {
-          // Should never take this long, but padded just in case this runs on a limited machine
-          f.get(1, TimeUnit.MINUTES);
-        } catch (TimeoutException e) {
-          assertWithMessage("BatcherImpl.close() is deadlocked").fail();
-        }
-      }
-    } finally {
-      executor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testConstructors() throws InterruptedException {
-    try (BatcherImpl batcher1 = createDefaultBatcherImpl(batchingSettings, null)) {
-      assertThat(batcher1.getFlowController()).isNotNull();
-      assertThat(batcher1.getFlowController().getLimitExceededBehavior())
-          .isEqualTo(batchingSettings.getFlowControlSettings().getLimitExceededBehavior());
-      assertThat(batcher1.getFlowController().getMaxElementCountLimit())
-          .isEqualTo(batchingSettings.getFlowControlSettings().getMaxOutstandingElementCount());
-      assertThat(batcher1.getFlowController().getMaxRequestBytesLimit())
-          .isEqualTo(batchingSettings.getFlowControlSettings().getMaxOutstandingRequestBytes());
-    }
-
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .setMaxOutstandingRequestBytes(6000L)
-                .build());
-    try (BatcherImpl batcher2 = createDefaultBatcherImpl(batchingSettings, flowController)) {
-      assertThat(batcher2.getFlowController()).isSameInstanceAs(flowController);
-    }
-  }
-
-  @Test
-  public void testThrottlingBlocking() throws Exception {
-    BatchingSettings settings =
-        BatchingSettings.newBuilder()
-            .setElementCountThreshold(1L)
-            .setRequestByteThreshold(1L)
-            .build();
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .setMaxOutstandingElementCount(1L)
-                .build());
-    ExecutorService executor = Executors.newFixedThreadPool(2);
-
-    ApiCallContext callContext = Mockito.mock(ApiCallContext.class);
-    ArgumentCaptor<ApiCallContext.Key<Long>> key =
-        ArgumentCaptor.forClass(ApiCallContext.Key.class);
-    ArgumentCaptor<Long> value = ArgumentCaptor.forClass(Long.class);
-    when(callContext.withOption(key.capture(), value.capture())).thenReturn(callContext);
-    long throttledTime = 50;
-
-    try (final Batcher<Integer, Integer> batcher =
-        new BatcherImpl<>(
-            SQUARER_BATCHING_DESC_V2,
-            callLabeledIntSquarer,
-            labeledIntList,
-            settings,
-            EXECUTOR,
-            flowController,
-            callContext)) {
-      flowController.reserve(1, 1);
-      Future future =
-          executor.submit(
-              new Runnable() {
-                @Override
-                public void run() {
-                  batcher.add(1);
-                }
-              });
-      // Add a little delay ensuring that the next step starts after batcher.add(1)
-      Thread.sleep(10);
-      executor.submit(
-          () -> {
-            try {
-              Thread.sleep(throttledTime);
-              flowController.release(1, 1);
-            } catch (InterruptedException e) {
-            }
-          });
-
-      try {
-        future.get(10, TimeUnit.MILLISECONDS);
-        assertWithMessage("adding elements to batcher should be blocked by FlowControlled").fail();
-      } catch (TimeoutException e) {
-        // expected
-      }
-
-      try {
-        future.get(3, TimeUnit.SECONDS);
-      } catch (TimeoutException e) {
-        assertWithMessage("adding elements to batcher should not be blocked").fail();
-      }
-
-      // Mockito recommends using verify() as the ONLY way to interact with Argument
-      // captors - otherwise it may incur in unexpected behaviour
-      Mockito.verify(callContext).withOption(key.capture(), value.capture());
-
-      // Verify that throttled time is recorded in ApiCallContext
-      assertThat(key.getValue()).isSameInstanceAs(Batcher.THROTTLED_TIME_KEY);
-      assertThat(value.getValue()).isAtLeast(throttledTime);
-    } finally {
-      executor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testThrottlingNonBlocking() throws Exception {
-    BatchingSettings settings =
-        BatchingSettings.newBuilder()
-            .setElementCountThreshold(1L)
-            .setRequestByteThreshold(1L)
-            .build();
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .setMaxOutstandingElementCount(1L)
-                .build());
-    try (final Batcher<Integer, Integer> batcher =
-        createDefaultBatcherImpl(settings, flowController)) {
-      flowController.reserve(1, 1);
-      try {
-        batcher.add(1);
-        assertWithMessage("Should throw exception because it exceeded FlowController limit").fail();
-      } catch (FlowControlRuntimeException e) {
-        assertThat(e.getMessage()).contains("The maximum number of batch elements");
-      }
-      flowController.release(1, 1);
-      batcher.add(1);
-    }
-  }
-
-  private void testElementTriggers(BatchingSettings settings) throws Exception {
-    underTest = createDefaultBatcherImpl(settings, null);
-    Future<Integer> result = underTest.add(4);
-    assertThat(result.isDone()).isFalse();
-    // After this element is added, the batch triggers sendOutstanding().
-    Future<Integer> anotherResult = underTest.add(5);
-    // Both the elements should be resolved now.
-    assertThat(result.isDone()).isTrue();
-    assertThat(result.get()).isEqualTo(16);
-    assertThat(anotherResult.isDone()).isTrue();
-  }
-
-  private BatcherImpl<Integer, Integer, LabeledIntList, List<Integer>> createDefaultBatcherImpl(
-      BatchingSettings settings, FlowController flowController) {
-    return new BatcherImpl<>(
-        SQUARER_BATCHING_DESC_V2,
-        callLabeledIntSquarer,
-        labeledIntList,
-        settings,
-        EXECUTOR,
-        flowController);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/BatcherStatsTest.java b/gax/src/test/java/com/google/api/gax/batching/BatcherStatsTest.java
deleted file mode 100644
index 1a95e4d3c..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/BatcherStatsTest.java
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.collect.ImmutableList;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class BatcherStatsTest {
-
-  @Test
-  public void testWhenNoException() {
-    BatcherStats batcherStats = new BatcherStats();
-    assertThat(batcherStats.asException()).isNull();
-  }
-
-  @Test
-  public void testRequestFailuresOnly() {
-    BatcherStats batcherStats = new BatcherStats();
-
-    batcherStats.recordBatchFailure(
-        ApiExceptionFactory.createException(
-            new RuntimeException(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false));
-
-    batcherStats.recordBatchFailure(new RuntimeException("Request failed"));
-
-    BatchingException exception = batcherStats.asException();
-    assertThat(exception).isNotNull();
-    assertThat(exception).hasMessageThat().contains("2 batches failed to apply");
-    assertThat(exception).hasMessageThat().contains("1 RuntimeException");
-    assertThat(exception).hasMessageThat().contains("1 ApiException(1 INVALID_ARGUMENT)");
-    assertThat(exception).hasMessageThat().contains("and 0 partial failures.");
-  }
-
-  @Test
-  public void testEntryFailureOnly() {
-    BatcherStats batcherStats = new BatcherStats();
-
-    SettableApiFuture<Integer> batchOneResult = SettableApiFuture.create();
-    batchOneResult.setException(new IllegalStateException("local element failure"));
-    batcherStats.recordBatchElementsCompletion(
-        ImmutableList.of(BatchEntry.create(1, batchOneResult)));
-
-    SettableApiFuture<Integer> batchTwoResult = SettableApiFuture.create();
-    batchTwoResult.setException(
-        ApiExceptionFactory.createException(
-            new RuntimeException(), FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), false));
-    batcherStats.recordBatchElementsCompletion(
-        ImmutableList.of(BatchEntry.create(2, batchTwoResult)));
-
-    BatchingException ex = batcherStats.asException();
-    assertThat(ex)
-        .hasMessageThat()
-        .contains("The 2 partial failures contained 2 entries that failed with:");
-    assertThat(ex).hasMessageThat().contains("1 ApiException(1 UNAVAILABLE)");
-    assertThat(ex).hasMessageThat().contains("1 IllegalStateException");
-  }
-
-  @Test
-  public void testRequestAndEntryFailures() {
-    BatcherStats batcherStats = new BatcherStats();
-
-    batcherStats.recordBatchFailure(new RuntimeException("Batch failure"));
-
-    SettableApiFuture<Integer> future = SettableApiFuture.create();
-    future.setException(
-        ApiExceptionFactory.createException(
-            new RuntimeException(), FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS), false));
-
-    batcherStats.recordBatchElementsCompletion(ImmutableList.of(BatchEntry.create(1, future)));
-
-    BatchingException ex = batcherStats.asException();
-    assertThat(ex)
-        .hasMessageThat()
-        .contains(
-            "Batching finished with 1 batches failed to apply due to: 1 RuntimeException and 1 "
-                + "partial failures. The 1 partial failures contained 1 entries that failed with:"
-                + " 1 ApiException(1 ALREADY_EXISTS).");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/BatchingCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/batching/BatchingCallSettingsTest.java
deleted file mode 100644
index 51339dfa1..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/BatchingCallSettingsTest.java
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.SQUARER_BATCHING_DESC_V2;
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.common.collect.ImmutableSet;
-import java.util.List;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatchingCallSettingsTest {
-
-  private static final BatchingSettings BATCHING_SETTINGS =
-      BatchingSettings.newBuilder()
-          .setElementCountThreshold(10L)
-          .setRequestByteThreshold(20L)
-          .setDelayThreshold(Duration.ofMillis(5))
-          .setFlowControlSettings(
-              FlowControlSettings.newBuilder()
-                  .setMaxOutstandingElementCount(100L)
-                  .setMaxOutstandingRequestBytes(100L)
-                  .setLimitExceededBehavior(FlowController.LimitExceededBehavior.Block)
-                  .build())
-          .build();
-
-  @Test
-  public void testEmptyBuilder() {
-    BatchingCallSettings.Builder<Integer, Integer, LabeledIntList, List<Integer>> builder =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC_V2);
-    assertThat(builder.getBatchingSettings()).isNull();
-    assertThat(builder.getRetryableCodes()).isEmpty();
-    assertThat(builder.getRetrySettings()).isNotNull();
-  }
-
-  @Test
-  public void testBuilder() {
-    BatchingCallSettings.Builder<Integer, Integer, LabeledIntList, List<Integer>> builder =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC_V2);
-
-    Set<StatusCode.Code> retryCodes = ImmutableSet.of(StatusCode.Code.UNAVAILABLE);
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-    builder
-        .setBatchingSettings(BATCHING_SETTINGS)
-        .setRetryableCodes(retryCodes)
-        .setRetrySettings(retrySettings);
-
-    BatchingCallSettings settings = builder.build();
-    assertThat(settings.getBatchingSettings()).isEqualTo(BATCHING_SETTINGS);
-    assertThat(settings.getRetryableCodes()).isEqualTo(retryCodes);
-    assertThat(settings.getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void testBuilderFromSettings() {
-    BatchingCallSettings.Builder<Integer, Integer, LabeledIntList, List<Integer>> builder =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC_V2);
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder().setTotalTimeout(Duration.ofMinutes(1)).build();
-    builder
-        .setBatchingSettings(BATCHING_SETTINGS)
-        .setRetryableCodes(StatusCode.Code.UNAVAILABLE, StatusCode.Code.UNAUTHENTICATED)
-        .setRetrySettings(retrySettings);
-
-    BatchingCallSettings settings = builder.build();
-    BatchingCallSettings.Builder newBuilder = settings.toBuilder();
-
-    assertThat(newBuilder.getBatchingSettings()).isEqualTo(BATCHING_SETTINGS);
-    assertThat(newBuilder.getRetryableCodes())
-        .containsExactly(StatusCode.Code.UNAVAILABLE, StatusCode.Code.UNAUTHENTICATED);
-    assertThat(newBuilder.getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void testMandatorySettings() {
-    Exception actualEx = null;
-    try {
-      BatchingCallSettings.newBuilder(null);
-    } catch (Exception ex) {
-      actualEx = ex;
-    }
-    assertThat(actualEx).isInstanceOf(NullPointerException.class);
-    actualEx = null;
-    try {
-      BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC_V2).build();
-    } catch (Exception ex) {
-      actualEx = ex;
-    }
-    assertThat(actualEx).isInstanceOf(IllegalStateException.class);
-  }
-
-  @Test
-  public void testToString() {
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-    Set<StatusCode.Code> retryCodes = ImmutableSet.of(StatusCode.Code.UNAUTHENTICATED);
-    BatchingCallSettings<Integer, Integer, LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC_V2)
-            .setRetryableCodes(retryCodes)
-            .setRetrySettings(retrySettings)
-            .setBatchingSettings(BATCHING_SETTINGS)
-            .build();
-
-    assertThat(batchingCallSettings.toString()).contains("retryableCodes=" + retryCodes);
-    assertThat(batchingCallSettings.toString()).contains("retrySettings=" + retrySettings);
-    assertThat(batchingCallSettings.toString()).contains("batchingSettings=" + BATCHING_SETTINGS);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/DynamicFlowControlSettingsTest.java b/gax/src/test/java/com/google/api/gax/batching/DynamicFlowControlSettingsTest.java
deleted file mode 100644
index afbf8ce1e..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/DynamicFlowControlSettingsTest.java
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
-
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class DynamicFlowControlSettingsTest {
-
-  @Test
-  public void testEmptyBuilder() {
-    DynamicFlowControlSettings.Builder builder = DynamicFlowControlSettings.newBuilder();
-    DynamicFlowControlSettings settings = builder.build();
-    assertNull(settings.getInitialOutstandingElementCount());
-    assertNull(settings.getInitialOutstandingRequestBytes());
-    assertNull(settings.getMaxOutstandingElementCount());
-    assertNull(settings.getMaxOutstandingRequestBytes());
-    assertNull(settings.getMinOutstandingElementCount());
-    assertNull(settings.getMinOutstandingRequestBytes());
-    assertEquals(LimitExceededBehavior.Block, settings.getLimitExceededBehavior());
-  }
-
-  @Test
-  public void testPartialSettingsIgnored() {
-    // If behavior is ignore, build shouldn't throw exceptions even when only one of the bytes or
-    // element limits is set
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .setMaxOutstandingElementCount(1L);
-    builder.build();
-    builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .setMinOutstandingRequestBytes(1L);
-    builder.build();
-  }
-
-  @Test
-  public void testBuilder() {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setInitialOutstandingElementCount(5L)
-            .setMaxOutstandingElementCount(10L)
-            .setMinOutstandingElementCount(1L)
-            .setInitialOutstandingRequestBytes(500L)
-            .setMaxOutstandingRequestBytes(1000L)
-            .setMinOutstandingRequestBytes(100L);
-    DynamicFlowControlSettings settings = builder.build();
-    assertThat(settings.getInitialOutstandingElementCount()).isEqualTo(5L);
-    assertThat(settings.getMaxOutstandingElementCount()).isEqualTo(10L);
-    assertThat(settings.getMinOutstandingElementCount()).isEqualTo(1L);
-    assertThat(settings.getInitialOutstandingRequestBytes()).isEqualTo(500L);
-    assertThat(settings.getMaxOutstandingRequestBytes()).isEqualTo(1000L);
-    assertThat(settings.getMinOutstandingRequestBytes()).isEqualTo(100L);
-  }
-
-  @Test
-  public void testValidElementCountSettings() {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setInitialOutstandingElementCount(5L)
-            .setMaxOutstandingElementCount(10L)
-            .setMinOutstandingElementCount(1L);
-    DynamicFlowControlSettings settings = builder.build();
-    assertThat(settings.getInitialOutstandingElementCount()).isEqualTo(5L);
-    assertThat(settings.getMaxOutstandingElementCount()).isEqualTo(10L);
-    assertThat(settings.getMinOutstandingElementCount()).isEqualTo(1L);
-  }
-
-  @Test
-  public void testValidRequestByteSettings() {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setInitialOutstandingRequestBytes(500L)
-            .setMaxOutstandingRequestBytes(1000L)
-            .setMinOutstandingRequestBytes(100L);
-    DynamicFlowControlSettings settings = builder.build();
-    assertThat(settings.getInitialOutstandingRequestBytes()).isEqualTo(500L);
-    assertThat(settings.getMaxOutstandingRequestBytes()).isEqualTo(1000L);
-    assertThat(settings.getMinOutstandingRequestBytes()).isEqualTo(100L);
-  }
-
-  @Test
-  public void testInvalidPartialSettings() {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder().setInitialOutstandingElementCount(1L);
-    try {
-      builder.build();
-      fail("Did not throw an illegal state exception");
-    } catch (IllegalStateException e) {
-      // Expected, ignore
-    }
-    builder = DynamicFlowControlSettings.newBuilder().setMinOutstandingRequestBytes(1L);
-    try {
-      builder.build();
-      fail("Did not throw an illegal state exception");
-    } catch (IllegalStateException e) {
-      // Expected, ignore
-    }
-  }
-
-  @Test
-  public void testInvalidArguments() {
-    testInvalidElementCount(-1, -5, 10);
-    testInvalidElementCount(5, -1, 10);
-    testInvalidElementCount(5, 0, 10);
-    testInvalidElementCount(5, 6, 10);
-    testInvalidElementCount(5, 2, 2);
-
-    testInvalidNumberOfBytes(-1, -5, 10);
-    testInvalidNumberOfBytes(5, -1, 10);
-    testInvalidNumberOfBytes(5, 0, 10);
-    testInvalidNumberOfBytes(5, 6, 10);
-    testInvalidNumberOfBytes(5, 2, 2);
-  }
-
-  private void testInvalidElementCount(long initial, long min, long max) {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setInitialOutstandingElementCount(initial)
-            .setMinOutstandingElementCount(min)
-            .setMaxOutstandingElementCount(max);
-    try {
-      builder.build();
-      fail("Did not throw an illegal state exception");
-    } catch (IllegalStateException e) {
-      // Expected, ignore
-    }
-  }
-
-  private void testInvalidNumberOfBytes(long initial, long min, long max) {
-    DynamicFlowControlSettings.Builder builder =
-        DynamicFlowControlSettings.newBuilder()
-            .setInitialOutstandingRequestBytes(initial)
-            .setMinOutstandingRequestBytes(min)
-            .setMaxOutstandingRequestBytes(max);
-    try {
-      builder.build();
-      fail("Did not throw an illegal state exception");
-    } catch (IllegalStateException e) {
-      // Expected, ignore
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/FlowControlEventStatsTest.java b/gax/src/test/java/com/google/api/gax/batching/FlowControlEventStatsTest.java
deleted file mode 100644
index 4dcb0c4ff..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/FlowControlEventStatsTest.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
-
-import com.google.api.gax.batching.FlowControlEventStats.FlowControlEvent;
-import com.google.api.gax.batching.FlowController.MaxOutstandingRequestBytesReachedException;
-import java.util.concurrent.TimeUnit;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class FlowControlEventStatsTest {
-
-  @Test
-  public void testCreateEvent() {
-    long timestamp = 12345, throttledTimeMs = 5000;
-    FlowControlEvent event = FlowControlEvent.createReserveDelayed(timestamp, throttledTimeMs);
-    assertEquals(event.getTimestampMs(), event.getTimestampMs());
-    assertEquals(throttledTimeMs / 1000, event.getThrottledTime(TimeUnit.SECONDS).longValue());
-    assertNull(event.getException());
-
-    MaxOutstandingRequestBytesReachedException exception =
-        new MaxOutstandingRequestBytesReachedException(100);
-    event = FlowControlEvent.createReserveDenied(timestamp, exception);
-    assertEquals(timestamp, event.getTimestampMs());
-    assertNotNull(event.getException());
-    assertEquals(exception, event.getException());
-    assertNull(event.getThrottledTime(TimeUnit.MILLISECONDS));
-
-    try {
-      event = FlowControlEvent.createReserveDenied(null);
-      fail("FlowControlEvent did not throw exception");
-    } catch (NullPointerException e) {
-      // expected, ignore
-    }
-  }
-
-  @Test
-  public void testGetLastEvent() {
-    FlowControlEventStats stats = new FlowControlEventStats();
-    long currentTime = System.currentTimeMillis();
-
-    for (int i = 1; i <= 10; i++) {
-      int timeElapsed = i;
-      stats.recordFlowControlEvent(
-          FlowControlEvent.createReserveDelayed(currentTime + timeElapsed, timeElapsed));
-    }
-
-    assertEquals(currentTime + 10, stats.getLastFlowControlEvent().getTimestampMs());
-    assertEquals(
-        10, stats.getLastFlowControlEvent().getThrottledTime(TimeUnit.MILLISECONDS).longValue());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/FlowControllerTest.java b/gax/src/test/java/com/google/api/gax/batching/FlowControllerTest.java
deleted file mode 100644
index cb82d28db..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/FlowControllerTest.java
+++ /dev/null
@@ -1,792 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.common.util.concurrent.SettableFuture;
-import java.lang.Thread.State;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import java.util.concurrent.atomic.AtomicInteger;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-/** Tests for {@link FlowController}. */
-@RunWith(JUnit4.class)
-public class FlowControllerTest {
-
-  @Test
-  public void testReserveRelease_ok() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    flowController.reserve(1, 1);
-    flowController.release(1, 1);
-  }
-
-  @Test
-  public void testInvalidArguments() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    flowController.reserve(0, 0);
-    try {
-      flowController.reserve(-1, 1);
-      fail("Must have thrown an illegal argument error");
-    } catch (IllegalArgumentException expected) {
-      // Expected
-    }
-    try {
-      flowController.reserve(1, -1);
-      fail("Must have thrown an illegal argument error");
-    } catch (IllegalArgumentException expected) {
-      // Expected
-    }
-    flowController.increaseThresholds(0, 0);
-    flowController.decreaseThresholds(0, 0);
-    try {
-      flowController.increaseThresholds(-1, 1);
-      fail("Must have thrown an illegal argument error");
-    } catch (IllegalArgumentException expected) {
-      // Expected
-    }
-    try {
-      flowController.decreaseThresholds(1, -1);
-      fail("Must have thrown an illegal argument error");
-    } catch (IllegalArgumentException expected) {
-      // Expected
-    }
-  }
-
-  @Test
-  public void testReserveRelease_noLimits_ok() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    flowController.reserve(1, 1);
-    flowController.release(1, 1);
-  }
-
-  @Test
-  public void testReserveRelease_ignore_ok() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(1L)
-                .setMaxOutstandingRequestBytes(1L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-                .build());
-
-    flowController.reserve(1, 1);
-    flowController.release(1, 1);
-  }
-
-  @Test
-  public void testReserveRelease_blockedByElementCount() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setMaxOutstandingRequestBytes(100L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    testBlockingReserveRelease(flowController, 10, 10);
-  }
-
-  @Test
-  public void testReserveRelease_blockedByElementCount_noBytesLimit() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    testBlockingReserveRelease(flowController, 10, 10);
-  }
-
-  @Test
-  public void testReserveRelease_blockedByNumberOfBytes() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(100L)
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    testBlockingReserveRelease(flowController, 10, 10);
-  }
-
-  @Test
-  public void testReserveRelease_blockedByNumberOfBytes_noElementCountLimit() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    testBlockingReserveRelease(flowController, 10, 10);
-  }
-
-  private static void testBlockingReserveRelease(
-      final FlowController flowController, final int maxElementCount, final int maxNumBytes)
-      throws Exception {
-
-    flowController.reserve(1, 1);
-
-    final SettableFuture<?> permitsReserved = SettableFuture.create();
-    Future<?> finished =
-        Executors.newCachedThreadPool()
-            .submit(
-                new Runnable() {
-                  @Override
-                  public void run() {
-                    try {
-                      permitsReserved.set(null);
-                      flowController.reserve(maxElementCount, maxNumBytes);
-                    } catch (FlowController.FlowControlException e) {
-                      throw new AssertionError(e);
-                    }
-                  }
-                });
-
-    permitsReserved.get();
-    assertFalse(finished.isDone());
-    flowController.release(1, 1);
-
-    finished.get(50, TimeUnit.MILLISECONDS);
-    flowController.release(maxElementCount, maxNumBytes);
-  }
-
-  @Test
-  public void testReserveRelease_rejectedByElementCount() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setMaxOutstandingRequestBytes(100L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    testRejectedReserveRelease(
-        flowController, 10, 10, FlowController.MaxOutstandingElementCountReachedException.class);
-    assertNotNull(flowController.getFlowControlEventStats().getLastFlowControlEvent());
-    assertThat(flowController.getFlowControlEventStats().getLastFlowControlEvent().getException())
-        .isInstanceOf(FlowController.MaxOutstandingElementCountReachedException.class);
-  }
-
-  @Test
-  public void testReserveRelease_rejectedByElementCount_noBytesLimit() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    testRejectedReserveRelease(
-        flowController, 10, 10, FlowController.MaxOutstandingElementCountReachedException.class);
-  }
-
-  @Test
-  public void testReserveRelease_rejectedByNumberOfBytes() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(100L)
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    testRejectedReserveRelease(
-        flowController, 10, 10, FlowController.MaxOutstandingRequestBytesReachedException.class);
-    assertNotNull(flowController.getFlowControlEventStats().getLastFlowControlEvent());
-    assertThat(flowController.getFlowControlEventStats().getLastFlowControlEvent().getException())
-        .isInstanceOf(FlowController.MaxOutstandingRequestBytesReachedException.class);
-  }
-
-  @Test
-  public void testReserveRelease_rejectedByNumberOfBytes_noElementCountLimit() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    testRejectedReserveRelease(
-        flowController, 10, 10, FlowController.MaxOutstandingRequestBytesReachedException.class);
-  }
-
-  @Test
-  public void testRestoreAfterFail() throws FlowController.FlowControlException {
-    FlowController flowController =
-        new FlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(2L)
-                .setMaxOutstandingRequestBytes(1L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    flowController.reserve(1, 1);
-
-    try {
-      flowController.reserve(1, 1);
-      throw new IllegalStateException("flowController should not have any bytes left");
-    } catch (FlowController.MaxOutstandingRequestBytesReachedException e) {
-      // Ignore.
-    }
-    flowController.reserve(1, 0);
-  }
-
-  @Test
-  public void testConstructedByDynamicFlowControlSetting() {
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setMinOutstandingElementCount(1L)
-                .setInitialOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(3L)
-                .setMinOutstandingRequestBytes(10L)
-                .setInitialOutstandingRequestBytes(20L)
-                .setMaxOutstandingRequestBytes(30L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-    assertEquals(1, flowController.getMinElementCountLimit().longValue());
-    assertEquals(2, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(3, flowController.getMaxElementCountLimit().longValue());
-    assertEquals(10, flowController.getMinRequestBytesLimit().longValue());
-    assertEquals(20, flowController.getCurrentRequestBytesLimit().longValue());
-    assertEquals(30, flowController.getMaxRequestBytesLimit().longValue());
-
-    flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setMinOutstandingElementCount(1L)
-                .setInitialOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(3L)
-                .setMinOutstandingRequestBytes(10L)
-                .setInitialOutstandingRequestBytes(20L)
-                .setMaxOutstandingRequestBytes(30L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-                .build());
-    assertNull(flowController.getMinElementCountLimit());
-    assertNull(flowController.getCurrentElementCountLimit());
-    assertNull(flowController.getMaxElementCountLimit());
-    assertNull(flowController.getMinRequestBytesLimit());
-    assertNull(flowController.getCurrentRequestBytesLimit());
-    assertNull(flowController.getMaxRequestBytesLimit());
-    assertNotNull(flowController.getFlowControlEventStats());
-  }
-
-  @Test
-  public void testIncreaseThresholds_blocking() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount(10L)
-                .setMinOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(20L)
-                .setInitialOutstandingRequestBytes(10L)
-                .setMinOutstandingRequestBytes(2L)
-                .setMaxOutstandingRequestBytes(20L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    assertEquals(10L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(10L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 10, 0);
-    testBlockingReserveRelease(flowController, 0, 10);
-
-    flowController.increaseThresholds(5, 5);
-    assertEquals(15L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(15L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 15, 0);
-    testBlockingReserveRelease(flowController, 0, 15);
-
-    // Thresholds can't go over max values. FlowController will set the values to max.
-    flowController.increaseThresholds(10, 10);
-    assertEquals(20L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(20L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 20, 0);
-    testBlockingReserveRelease(flowController, 0, 20);
-  }
-
-  @Test
-  public void testDecreaseThresholds_blocking() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount(10L)
-                .setMinOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(20L)
-                .setInitialOutstandingRequestBytes(10L)
-                .setMinOutstandingRequestBytes(2L)
-                .setMaxOutstandingRequestBytes(20L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-
-    assertEquals(10L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(10L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 10, 0);
-    testBlockingReserveRelease(flowController, 0, 10);
-
-    flowController.decreaseThresholds(5, 5);
-    assertEquals(5L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(5L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 5, 0);
-    testBlockingReserveRelease(flowController, 0, 5);
-
-    // Thresholds can't go below min values. FlowController will set them to min svalues.
-    flowController.decreaseThresholds(5, 5);
-    assertEquals(2L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(2L, flowController.getCurrentRequestBytesLimit().longValue());
-    testBlockingReserveRelease(flowController, 2, 0);
-    testBlockingReserveRelease(flowController, 0, 2);
-  }
-
-  @Test
-  public void testIncreaseThresholds_nonBlocking() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount(10L)
-                .setMinOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(20L)
-                .setInitialOutstandingRequestBytes(10L)
-                .setMinOutstandingRequestBytes(2L)
-                .setMaxOutstandingRequestBytes(20L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    assertEquals(10L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(10L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 10, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 10, FlowController.MaxOutstandingRequestBytesReachedException.class);
-
-    flowController.increaseThresholds(5, 5);
-    assertEquals(15L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(15L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 15, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 15, FlowController.MaxOutstandingRequestBytesReachedException.class);
-
-    // Thresholds can't go over max values. FlowController will set the values to max.
-    flowController.increaseThresholds(10, 10);
-    assertEquals(20L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(20L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 20, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 20, FlowController.MaxOutstandingRequestBytesReachedException.class);
-  }
-
-  @Test
-  public void testDecreaseThresholds_nonBlocking() throws Exception {
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount(10L)
-                .setMinOutstandingElementCount(2L)
-                .setMaxOutstandingElementCount(20L)
-                .setInitialOutstandingRequestBytes(10L)
-                .setMinOutstandingRequestBytes(2L)
-                .setMaxOutstandingRequestBytes(20L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-
-    assertEquals(10L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(10L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 10, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 10, FlowController.MaxOutstandingRequestBytesReachedException.class);
-
-    flowController.decreaseThresholds(5, 5);
-    assertEquals(5L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(5L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 5, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 5, FlowController.MaxOutstandingRequestBytesReachedException.class);
-
-    // Thresholds can't go below min values. FlowController will set them to min svalues.
-    flowController.decreaseThresholds(5, 5);
-    assertEquals(2L, flowController.getCurrentElementCountLimit().longValue());
-    assertEquals(2L, flowController.getCurrentRequestBytesLimit().longValue());
-    testRejectedReserveRelease(
-        flowController, 2, 0, FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController, 0, 2, FlowController.MaxOutstandingRequestBytesReachedException.class);
-  }
-
-  private void testRejectedReserveRelease(
-      FlowController flowController,
-      int maxElementCount,
-      int maxNumBytes,
-      Class<? extends FlowController.FlowControlException> expectedException)
-      throws FlowController.FlowControlException {
-
-    flowController.reserve(1, 1);
-
-    try {
-      flowController.reserve(maxElementCount, maxNumBytes);
-      fail("Should thrown a FlowController.FlowControlException");
-    } catch (FlowController.FlowControlException e) {
-      assertTrue(expectedException.isInstance(e));
-    }
-
-    flowController.release(1, 1);
-    flowController.reserve(maxElementCount, maxNumBytes);
-    flowController.release(maxElementCount, maxNumBytes);
-  }
-
-  @Test
-  public void testConcurrentUpdateThresholds_blocking() throws Exception {
-    int initialValue = 5000;
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount((long) initialValue)
-                .setMinOutstandingElementCount(1L)
-                .setMaxOutstandingElementCount(10000L)
-                .setInitialOutstandingRequestBytes((long) initialValue)
-                .setMinOutstandingRequestBytes(1L)
-                .setMaxOutstandingRequestBytes(50000L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-    final AtomicInteger totalIncreased = new AtomicInteger(0);
-    final AtomicInteger totalDecreased = new AtomicInteger(0);
-    final AtomicInteger releasedCounter = new AtomicInteger(0);
-
-    List<Future> reserveThreads =
-        testConcurrentUpdates(
-            flowController, 100, 100, 10, totalIncreased, totalDecreased, releasedCounter);
-    for (Future t : reserveThreads) {
-      t.get(200, TimeUnit.MILLISECONDS);
-    }
-    assertEquals(reserveThreads.size(), releasedCounter.get());
-    assertTrue(totalIncreased.get() > 0);
-    assertTrue(totalDecreased.get() > 0);
-    int expectedValue = initialValue + totalIncreased.get() - totalDecreased.get();
-    assertEquals(expectedValue, flowController.getCurrentRequestBytesLimit().longValue());
-    assertEquals(expectedValue, flowController.getCurrentElementCountLimit().longValue());
-    testBlockingReserveRelease(flowController, expectedValue, 0);
-    testBlockingReserveRelease(flowController, 0, expectedValue);
-  }
-
-  @Test
-  public void testConcurrentUpdateThresholds_nonBlocking() throws Exception {
-    int initialValue = 5000;
-    FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount((long) initialValue)
-                .setMinOutstandingElementCount(1L)
-                .setMaxOutstandingElementCount(10000L)
-                .setInitialOutstandingRequestBytes((long) initialValue)
-                .setMinOutstandingRequestBytes(1L)
-                .setMaxOutstandingRequestBytes(50000L)
-                .setLimitExceededBehavior(LimitExceededBehavior.ThrowException)
-                .build());
-    AtomicInteger totalIncreased = new AtomicInteger(0);
-    AtomicInteger totalDecreased = new AtomicInteger(0);
-    AtomicInteger releasedCounter = new AtomicInteger(0);
-    List<Future> reserveThreads =
-        testConcurrentUpdates(
-            flowController, 100, 100, 100, totalIncreased, totalDecreased, releasedCounter);
-    for (Future t : reserveThreads) {
-      t.get(200, TimeUnit.MILLISECONDS);
-    }
-    assertEquals(reserveThreads.size(), releasedCounter.get());
-    assertTrue(totalIncreased.get() > 0);
-    assertTrue(totalDecreased.get() > 0);
-    int expectedValue = initialValue + totalIncreased.get() - totalDecreased.get();
-    assertEquals(expectedValue, flowController.getCurrentRequestBytesLimit().longValue());
-    assertEquals(expectedValue, flowController.getCurrentElementCountLimit().longValue());
-    testRejectedReserveRelease(
-        flowController,
-        expectedValue,
-        0,
-        FlowController.MaxOutstandingElementCountReachedException.class);
-    testRejectedReserveRelease(
-        flowController,
-        0,
-        expectedValue,
-        FlowController.MaxOutstandingRequestBytesReachedException.class);
-  }
-
-  @Test
-  public void testNumberOfBytesOutOfBoundaryWontDeadlock() throws Exception {
-    // Test the special case where in FlowController#reserve, to avoid deadlocks, it allows
-    // reserving byte size greater than current request bytes limit.
-    int initial = 50;
-    final FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingRequestBytes((long) initial)
-                .setMinOutstandingRequestBytes(1L)
-                .setMaxOutstandingRequestBytes(100L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-    flowController.reserve(0, 10);
-    // will be blocked by reserve 10
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                try {
-                  flowController.reserve(0, 100);
-                } catch (FlowControlException e) {
-                }
-              }
-            });
-    t.start();
-    // wait for thread to start, and check it should be blocked
-    Thread.sleep(50);
-    assertEquals(State.WAITING, t.getState());
-    // increase and decrease should not be blocked
-    int increase = 5, decrease = 20;
-    flowController.decreaseThresholds(0, decrease);
-    flowController.increaseThresholds(0, increase);
-    // releasing 10 permits should unblock t
-    flowController.release(0, 10);
-    t.join();
-    int expectedNewThreshold = initial - decrease + increase;
-    assertEquals(expectedNewThreshold, flowController.getCurrentRequestBytesLimit().longValue());
-    flowController.release(0, 100);
-    // Verify no extra permits are released to the semaphore
-    testBlockingReserveRelease(flowController, 0, expectedNewThreshold);
-  }
-
-  @Test(timeout = 500)
-  public void testElementCountsOutOfBoundaryWontDeadlock() throws Exception {
-    // Test the special case where in FlowController#reserve, to avoid deadlocks, it allows
-    // reserving byte size greater than current request bytes limit.
-    final int initial = 50;
-    final FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount((long) initial)
-                .setMinOutstandingElementCount(1L)
-                .setMaxOutstandingElementCount(100L)
-                .setInitialOutstandingRequestBytes((long) initial)
-                .setMinOutstandingRequestBytes(1L)
-                .setMaxOutstandingRequestBytes(100L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                try {
-                  flowController.reserve(initial + 10, 10);
-                } catch (FlowControlException e) {
-                }
-              }
-            });
-    t.start();
-    // wait for thread to start, and check it should be blocked
-    Thread.sleep(50);
-    assertEquals(State.WAITING, t.getState());
-    // increase and decrease should not be blocked
-    int increase = 5, decrease = 20;
-    flowController.decreaseThresholds(decrease, 0);
-    flowController.increaseThresholds(increase, 0);
-    // reserve 1 permit should also not be blocked
-    flowController.reserve(1, 1);
-    flowController.release(1, 1);
-    // increasing permits to unblock
-    flowController.increaseThresholds(50, 0);
-    t.join();
-  }
-
-  @Test
-  public void testFlowControlBlockEventIsRecorded() throws Exception {
-    // Test when reserve is blocked for at least FlowController#RESERVE_FLOW_CONTROL_THRESHOLD_MS,
-    // FlowController will record the FlowControlEvent in FlowControlEventStats
-    final FlowController flowController =
-        new FlowController(
-            DynamicFlowControlSettings.newBuilder()
-                .setInitialOutstandingElementCount(5L)
-                .setMinOutstandingElementCount(1L)
-                .setMaxOutstandingElementCount(10L)
-                .setInitialOutstandingRequestBytes(5L)
-                .setMinOutstandingRequestBytes(1L)
-                .setMaxOutstandingRequestBytes(10L)
-                .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                .build());
-    Runnable runnable =
-        new Runnable() {
-          @Override
-          public void run() {
-            try {
-              flowController.reserve(1, 1);
-            } catch (FlowController.FlowControlException e) {
-              throw new AssertionError(e);
-            }
-          }
-        };
-    // blocked by element. Reserve all 5 elements first, reserve in the runnable will be blocked
-    flowController.reserve(5, 1);
-    Future<?> finished1 = Executors.newSingleThreadExecutor().submit(runnable);
-    try {
-      finished1.get(50, TimeUnit.MILLISECONDS);
-      fail("reserve should block");
-    } catch (TimeoutException e) {
-      // expected
-    }
-    assertFalse(finished1.isDone());
-    flowController.release(5, 1);
-    // After other elements are released, reserve in the runnable should go through. Since reserve
-    // was blocked for longer than 1 millisecond, FlowController should record this event in
-    // FlowControlEventStats.
-    finished1.get(50, TimeUnit.MILLISECONDS);
-    assertNotNull(flowController.getFlowControlEventStats().getLastFlowControlEvent());
-    assertNotNull(
-        flowController
-            .getFlowControlEventStats()
-            .getLastFlowControlEvent()
-            .getThrottledTime(TimeUnit.MILLISECONDS));
-    flowController.release(1, 1);
-
-    // Similar to blocked by element, test blocking by bytes.
-    flowController.reserve(1, 5);
-    Future<?> finished2 = Executors.newSingleThreadExecutor().submit(runnable);
-    try {
-      finished2.get(50, TimeUnit.MILLISECONDS);
-      fail("reserve should block");
-    } catch (TimeoutException e) {
-      // expected
-    }
-    assertFalse(finished2.isDone());
-    long currentTime = System.currentTimeMillis();
-    flowController.release(1, 5);
-    finished2.get(50, TimeUnit.MILLISECONDS);
-    assertNotNull(flowController.getFlowControlEventStats().getLastFlowControlEvent());
-    // Make sure this newer event is recorded
-    assertThat(flowController.getFlowControlEventStats().getLastFlowControlEvent().getTimestampMs())
-        .isAtLeast(currentTime);
-  }
-
-  private List<Future> testConcurrentUpdates(
-      final FlowController flowController,
-      final int increaseStepRange,
-      final int decreaseStepRange,
-      final int reserve,
-      final AtomicInteger totalIncreased,
-      final AtomicInteger totalDecreased,
-      final AtomicInteger releasedCounter)
-      throws InterruptedException, TimeoutException, ExecutionException {
-    final Random random = new Random();
-    Runnable increaseRunnable =
-        new Runnable() {
-          @Override
-          public void run() {
-            int increase = random.nextInt(increaseStepRange) + 1;
-            flowController.increaseThresholds(increase, increase);
-            totalIncreased.addAndGet(increase);
-          }
-        };
-    Runnable decreaseRunnable =
-        new Runnable() {
-          @Override
-          public void run() {
-            int decrease = random.nextInt(decreaseStepRange) + 1;
-            flowController.decreaseThresholds(decrease, decrease);
-            totalDecreased.addAndGet(decrease);
-          }
-        };
-    Runnable reserveReleaseRunnable =
-        new Runnable() {
-          @Override
-          public void run() {
-            try {
-              flowController.reserve(reserve, reserve);
-              flowController.release(reserve, reserve);
-              releasedCounter.incrementAndGet();
-            } catch (Exception e) {
-            }
-          }
-        };
-    List<Future> updateFuture = new ArrayList<>();
-    List<Future> reserveReleaseFuture = new ArrayList<>();
-    ExecutorService executors = Executors.newFixedThreadPool(10);
-    ExecutorService reserveExecutor = Executors.newFixedThreadPool(10);
-    for (int i = 0; i < 5; i++) {
-      updateFuture.add(executors.submit(increaseRunnable));
-      updateFuture.add(executors.submit(decreaseRunnable));
-      reserveReleaseFuture.add(reserveExecutor.submit(reserveReleaseRunnable));
-    }
-    for (Future t : updateFuture) {
-      t.get(50, TimeUnit.MILLISECONDS);
-    }
-    executors.shutdown();
-    return reserveReleaseFuture;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/Semaphore64Test.java b/gax/src/test/java/com/google/api/gax/batching/Semaphore64Test.java
deleted file mode 100644
index a0a8a89aa..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/Semaphore64Test.java
+++ /dev/null
@@ -1,288 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-import java.util.LinkedList;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class Semaphore64Test {
-  @Test(expected = IllegalArgumentException.class)
-  public void testNegative() {
-    Semaphore64 semaphore = new BlockingSemaphore(1);
-    semaphore.acquire(-1);
-  }
-
-  @Test
-  public void testReturning() {
-    Semaphore64 semaphore = new NonBlockingSemaphore(1);
-    assertTrue(semaphore.acquire(1));
-    assertFalse(semaphore.acquire(1));
-    semaphore.release(1);
-    assertTrue(semaphore.acquire(1));
-  }
-
-  @Test(timeout = 500)
-  public void testBlocking() throws InterruptedException {
-    final Semaphore64 semaphore = new BlockingSemaphore(1);
-    semaphore.acquire(1);
-
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(1);
-              }
-            });
-    t.start();
-
-    Thread.sleep(50);
-    assertTrue(t.isAlive());
-
-    semaphore.release(1);
-    t.join();
-  }
-
-  @Test
-  public void testReducePermitLimitNonBlocking() {
-    final Semaphore64 semaphore = new NonBlockingSemaphore(5);
-    semaphore.reducePermitLimit(3);
-    assertFalse(semaphore.acquire(3));
-    assertTrue(semaphore.acquire(2));
-    assertEquals(2, semaphore.getPermitLimit());
-  }
-
-  @Test(timeout = 500)
-  public void testReducePermitLimitBlocking() throws InterruptedException {
-    final Semaphore64 semaphore = new BlockingSemaphore(2);
-
-    semaphore.reducePermitLimit(1);
-    semaphore.acquire(1);
-
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(1);
-              }
-            });
-    t.start();
-
-    Thread.sleep(50);
-    assertTrue(t.isAlive());
-
-    semaphore.release(1);
-    t.join();
-
-    assertEquals(1, semaphore.getPermitLimit());
-  }
-
-  @Test
-  public void testAcquirePartialNonBlocking() {
-    Semaphore64 semaphore = new NonBlockingSemaphore(5);
-    assertTrue(semaphore.acquirePartial(6));
-    assertFalse(semaphore.acquire(1));
-    semaphore.release(6);
-    assertTrue(semaphore.acquire(1));
-    assertFalse(semaphore.acquirePartial(6));
-    // limit should still be 5
-    assertEquals(5, semaphore.getPermitLimit());
-  }
-
-  @Test(timeout = 500)
-  public void testAcquirePartialBlocking() throws Exception {
-    final Semaphore64 semaphore = new BlockingSemaphore(5);
-    semaphore.acquirePartial(6);
-    Thread t1 =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(1);
-              }
-            });
-    t1.start();
-    // wait for thread to start
-    Thread.sleep(100);
-    assertTrue(t1.isAlive());
-    semaphore.release(6);
-    t1.join();
-
-    // now there should be 4 permits available, acquiring 6 should block
-    Thread t2 =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquirePartial(6);
-              }
-            });
-    t2.start();
-    // wait fo thread to start
-    Thread.sleep(100);
-    assertTrue(t2.isAlive());
-    // limit should still be 5 and get limit should not block
-    assertEquals(5, semaphore.getPermitLimit());
-  }
-
-  @Test
-  public void testIncreasePermitLimitNonBlocking() {
-    Semaphore64 semaphore = new NonBlockingSemaphore(1);
-    assertFalse(semaphore.acquire(2));
-    semaphore.increasePermitLimit(1);
-    assertTrue(semaphore.acquire(2));
-    semaphore.release(2);
-    assertFalse(semaphore.acquire(3));
-    assertEquals(2, semaphore.getPermitLimit());
-  }
-
-  @Test(timeout = 500)
-  public void testIncreasePermitLimitBlocking() throws Exception {
-    final Semaphore64 semaphore = new BlockingSemaphore(1);
-    semaphore.acquire(1);
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(1);
-              }
-            });
-    t.start();
-
-    Thread.sleep(50);
-    assertTrue(t.isAlive());
-
-    semaphore.increasePermitLimit(1);
-    t.join();
-    semaphore.release(2);
-
-    semaphore.acquire(2);
-    assertEquals(2, semaphore.getPermitLimit());
-  }
-
-  @Test(timeout = 500)
-  public void testReleaseWontOverflowNonBlocking() throws Exception {
-    final Semaphore64 semaphore = new NonBlockingSemaphore(10);
-    List<Thread> threads = new LinkedList<>();
-    for (int i = 0; i < 20; i++) {
-      final int id = i;
-      Thread t =
-          new Thread(
-              new Runnable() {
-                @Override
-                public void run() {
-                  semaphore.acquire(5);
-                  semaphore.release(6);
-                }
-              });
-      threads.add(t);
-    }
-    for (Thread t : threads) {
-      t.start();
-    }
-    for (Thread t : threads) {
-      t.join();
-    }
-    // Limit should still be 10 and only 10 permits should be available
-    assertEquals(10, semaphore.getPermitLimit());
-    assertFalse(semaphore.acquire(11));
-    assertTrue(semaphore.acquire(10));
-  }
-
-  @Test(timeout = 500)
-  public void testReleaseWontOverflowBlocking() throws Exception {
-    final Semaphore64 semaphore = new BlockingSemaphore(10);
-    semaphore.acquire(5);
-    semaphore.release(6);
-    // Limit should still be 10 and only 10 permits should be available
-    assertEquals(10, semaphore.getPermitLimit());
-    semaphore.acquire(10);
-    semaphore.release(10);
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(11);
-              }
-            });
-    t.start();
-    Thread.sleep(100);
-    assertTrue(t.isAlive());
-  }
-
-  @Test
-  public void testPermitLimitUnderflowNonBlocking() {
-    Semaphore64 semaphore = new NonBlockingSemaphore(10);
-    try {
-      semaphore.reducePermitLimit(10);
-      fail("Did not throw illegal state exception");
-    } catch (IllegalStateException e) {
-    }
-    assertEquals(10, semaphore.getPermitLimit());
-    assertFalse(semaphore.acquire(11));
-    assertTrue(semaphore.acquire(10));
-  }
-
-  @Test(timeout = 500)
-  public void testPermitLimitUnderflowBlocking() throws Exception {
-    final Semaphore64 semaphore = new BlockingSemaphore(10);
-    try {
-      semaphore.reducePermitLimit(10);
-      fail("Did not throw illegal state exception");
-    } catch (IllegalStateException e) {
-    }
-    assertEquals(10, semaphore.getPermitLimit());
-    semaphore.acquire(10);
-    semaphore.release(10);
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                semaphore.acquire(11);
-              }
-            });
-    t.start();
-    Thread.sleep(100);
-    assertTrue(t.isAlive());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/ThresholdBatcherTest.java b/gax/src/test/java/com/google/api/gax/batching/ThresholdBatcherTest.java
deleted file mode 100644
index 45eaa84b7..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/ThresholdBatcherTest.java
+++ /dev/null
@@ -1,360 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.batching.FlowController.FlowControlException;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.Assert;
-import org.junit.Test;
-import org.threeten.bp.Duration;
-
-public class ThresholdBatcherTest {
-
-  private static final ScheduledExecutorService EXECUTOR = new ScheduledThreadPoolExecutor(1);
-
-  private static FlowController getDisabledFlowController() {
-    return new FlowController(
-        FlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .build());
-  }
-
-  private static <T> BatchingFlowController<T> getDisabledBatchingFlowController() {
-    return new BatchingFlowController<>(
-        getDisabledFlowController(),
-        new ElementCounter<T>() {
-          @Override
-          public long count(T t) {
-            return 1;
-          }
-        },
-        new ElementCounter<T>() {
-          @Override
-          public long count(T t) {
-            return 1;
-          }
-        });
-  }
-
-  private static TrackedFlowController trackedFlowController;
-
-  private static BatchingFlowController<SimpleBatch> getTrackedIntegerBatchingFlowController(
-      Long elementCount, Long byteCount, LimitExceededBehavior limitExceededBehaviour) {
-    trackedFlowController =
-        new TrackedFlowController(
-            FlowControlSettings.newBuilder()
-                .setMaxOutstandingElementCount(elementCount)
-                .setMaxOutstandingRequestBytes(byteCount)
-                .setLimitExceededBehavior(limitExceededBehaviour)
-                .build());
-    return new BatchingFlowController<>(
-        trackedFlowController,
-        new ElementCounter<SimpleBatch>() {
-          @Override
-          public long count(SimpleBatch t) {
-            return t.getIntegers().size();
-          }
-        },
-        new ElementCounter<SimpleBatch>() {
-          @Override
-          public long count(SimpleBatch t) {
-            long counter = 0;
-            for (Integer i : t.integers) {
-              counter += i;
-            }
-            return counter;
-          }
-        });
-  }
-
-  private static class SimpleBatch {
-
-    private final List<Integer> integers = new ArrayList<>();
-
-    private static SimpleBatch fromInteger(Integer integer) {
-      SimpleBatch batch = new SimpleBatch();
-      batch.integers.add(integer);
-      return batch;
-    }
-
-    public void merge(SimpleBatch t) {
-      integers.addAll(t.integers);
-    }
-
-    private List<Integer> getIntegers() {
-      return integers;
-    }
-  }
-
-  private static class SimpleBatchMerger implements BatchMerger<SimpleBatch> {
-    @Override
-    public void merge(SimpleBatch batch, SimpleBatch newBatch) {
-      batch.merge(newBatch);
-    }
-  }
-
-  private static ThresholdBatcher.Builder<SimpleBatch> createSimpleBatcherBuidler(
-      AccumulatingBatchReceiver<SimpleBatch> receiver) {
-    return ThresholdBatcher.<SimpleBatch>newBuilder()
-        .setThresholds(BatchingThresholds.<SimpleBatch>create(100))
-        .setExecutor(EXECUTOR)
-        .setMaxDelay(Duration.ofMillis(10000))
-        .setReceiver(receiver)
-        .setFlowController(ThresholdBatcherTest.<SimpleBatch>getDisabledBatchingFlowController())
-        .setBatchMerger(new SimpleBatchMerger());
-  }
-
-  @Test
-  public void testAdd() throws Exception {
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFuture(null));
-    ThresholdBatcher<SimpleBatch> batcher = createSimpleBatcherBuidler(receiver).build();
-    batcher.add(SimpleBatch.fromInteger(14));
-    assertThat(batcher.isEmpty()).isFalse();
-    assertThat(receiver.getBatches()).hasSize(0);
-
-    batcher.pushCurrentBatch().get();
-    assertThat(batcher.isEmpty()).isTrue();
-    assertThat(receiver.getBatches()).hasSize(1);
-    assertThat(receiver.getBatches().get(0).getIntegers()).isEqualTo(Arrays.asList(14));
-  }
-
-  @Test
-  public void testBatching() throws Exception {
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFuture(null));
-    ThresholdBatcher<SimpleBatch> batcher =
-        createSimpleBatcherBuidler(receiver)
-            .setThresholds(BatchingThresholds.<SimpleBatch>create(2))
-            .build();
-
-    batcher.add(SimpleBatch.fromInteger(3));
-    batcher.add(SimpleBatch.fromInteger(5));
-    // Give time for the executor to push the batch
-    Thread.sleep(100);
-    assertThat(receiver.getBatches()).hasSize(1);
-
-    batcher.add(SimpleBatch.fromInteger(7));
-    batcher.add(SimpleBatch.fromInteger(9));
-    // Give time for the executor to push the batch
-    Thread.sleep(100);
-    assertThat(receiver.getBatches()).hasSize(2);
-
-    batcher.add(SimpleBatch.fromInteger(11));
-
-    batcher.pushCurrentBatch().get();
-
-    List<List<Integer>> expected =
-        Arrays.asList(Arrays.asList(3, 5), Arrays.asList(7, 9), Arrays.asList(11));
-    List<List<Integer>> actual = new ArrayList<>();
-    for (SimpleBatch batch : receiver.getBatches()) {
-      actual.add(batch.getIntegers());
-    }
-    assertThat(actual).isEqualTo(expected);
-  }
-
-  @Test
-  public void testBatchingWithDelay() throws Exception {
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFuture(null));
-    ThresholdBatcher<SimpleBatch> batcher =
-        createSimpleBatcherBuidler(receiver).setMaxDelay(Duration.ofMillis(100)).build();
-
-    batcher.add(SimpleBatch.fromInteger(3));
-    batcher.add(SimpleBatch.fromInteger(5));
-    // Give time for the delay to trigger and push the batch
-    Thread.sleep(500);
-    assertThat(receiver.getBatches()).hasSize(1);
-
-    batcher.add(SimpleBatch.fromInteger(11));
-
-    batcher.pushCurrentBatch().get();
-
-    List<List<Integer>> expected = Arrays.asList(Arrays.asList(3, 5), Arrays.asList(11));
-    List<List<Integer>> actual = new ArrayList<>();
-    for (SimpleBatch batch : receiver.getBatches()) {
-      actual.add(batch.getIntegers());
-    }
-    assertThat(actual).isEqualTo(expected);
-  }
-
-  @Test
-  public void testExceptionWithNullFlowController() {
-    try {
-      ThresholdBatcher.<SimpleBatch>newBuilder()
-          .setThresholds(BatchingThresholds.<SimpleBatch>create(100))
-          .setExecutor(EXECUTOR)
-          .setMaxDelay(Duration.ofMillis(10000))
-          .setReceiver(
-              new AccumulatingBatchReceiver<SimpleBatch>(ApiFutures.<Void>immediateFuture(null)))
-          .setBatchMerger(new SimpleBatchMerger())
-          .build();
-      Assert.fail("ThresholdBatcher should have thrown an exception");
-    } catch (NullPointerException expected) {
-      assertThat(expected).isInstanceOf(NullPointerException.class);
-    }
-  }
-
-  @Test
-  public void testBatchingWithFlowControl() throws Exception {
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFuture(null));
-    ThresholdBatcher<SimpleBatch> batcher =
-        createSimpleBatcherBuidler(receiver)
-            .setThresholds(BatchingThresholds.<SimpleBatch>create(2))
-            .setFlowController(
-                getTrackedIntegerBatchingFlowController(2L, null, LimitExceededBehavior.Block))
-            .build();
-
-    assertThat(trackedFlowController.getElementsReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getElementsReleased()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReleased()).isEqualTo(0);
-
-    batcher.add(SimpleBatch.fromInteger(3));
-    batcher.add(SimpleBatch.fromInteger(5));
-    batcher.add(
-        SimpleBatch.fromInteger(7)); // We expect to block here until the first batch is handled
-    assertThat(receiver.getBatches()).hasSize(1);
-    batcher.add(SimpleBatch.fromInteger(9));
-    batcher.add(
-        SimpleBatch.fromInteger(11)); // We expect to block here until the second batch is handled
-    assertThat(receiver.getBatches()).hasSize(2);
-
-    batcher.pushCurrentBatch().get();
-
-    List<List<Integer>> expected =
-        Arrays.asList(Arrays.asList(3, 5), Arrays.asList(7, 9), Arrays.asList(11));
-    List<List<Integer>> actual = new ArrayList<>();
-    for (SimpleBatch batch : receiver.getBatches()) {
-      actual.add(batch.getIntegers());
-    }
-    assertThat(actual).isEqualTo(expected);
-
-    assertThat(trackedFlowController.getElementsReserved())
-        .isEqualTo(trackedFlowController.getElementsReleased());
-    assertThat(trackedFlowController.getBytesReserved())
-        .isEqualTo(trackedFlowController.getBytesReleased());
-  }
-
-  @Test
-  public void testBatchingFlowControlExceptionRecovery() throws Exception {
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFuture(null));
-    ThresholdBatcher<SimpleBatch> batcher =
-        createSimpleBatcherBuidler(receiver)
-            .setThresholds(BatchingThresholds.<SimpleBatch>create(4))
-            .setFlowController(
-                getTrackedIntegerBatchingFlowController(
-                    3L, null, LimitExceededBehavior.ThrowException))
-            .build();
-
-    assertThat(trackedFlowController.getElementsReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getElementsReleased()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReleased()).isEqualTo(0);
-
-    batcher.add(SimpleBatch.fromInteger(3));
-    batcher.add(SimpleBatch.fromInteger(5));
-    batcher.add(SimpleBatch.fromInteger(7));
-    try {
-      batcher.add(SimpleBatch.fromInteger(9));
-      Assert.fail("expected exception");
-    } catch (FlowControlException e) {
-    }
-    batcher.pushCurrentBatch().get();
-    assertThat(receiver.getBatches()).hasSize(1);
-    batcher.add(SimpleBatch.fromInteger(11));
-    batcher.add(SimpleBatch.fromInteger(13));
-    batcher.pushCurrentBatch().get();
-
-    List<List<Integer>> expected = Arrays.asList(Arrays.asList(3, 5, 7), Arrays.asList(11, 13));
-    List<List<Integer>> actual = new ArrayList<>();
-    for (SimpleBatch batch : receiver.getBatches()) {
-      actual.add(batch.getIntegers());
-    }
-    assertThat(actual).isEqualTo(expected);
-
-    assertThat(trackedFlowController.getElementsReserved())
-        .isEqualTo(trackedFlowController.getElementsReleased());
-    assertThat(trackedFlowController.getBytesReserved())
-        .isEqualTo(trackedFlowController.getBytesReleased());
-  }
-
-  @Test
-  public void testBatchingFailedRPC() throws Exception {
-    Exception ex = new IllegalStateException("does nothing, unsuccessfully");
-    AccumulatingBatchReceiver<SimpleBatch> receiver =
-        new AccumulatingBatchReceiver<>(ApiFutures.<Void>immediateFailedFuture(ex));
-    ThresholdBatcher<SimpleBatch> batcher =
-        createSimpleBatcherBuidler(receiver)
-            .setThresholds(BatchingThresholds.<SimpleBatch>create(4))
-            .setFlowController(
-                getTrackedIntegerBatchingFlowController(
-                    3L, null, LimitExceededBehavior.ThrowException))
-            .build();
-
-    assertThat(trackedFlowController.getElementsReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getElementsReleased()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReserved()).isEqualTo(0);
-    assertThat(trackedFlowController.getBytesReleased()).isEqualTo(0);
-
-    batcher.add(SimpleBatch.fromInteger(3));
-    try {
-      batcher.pushCurrentBatch().get();
-      Assert.fail("expected exception");
-    } catch (Exception e) {
-      assertThat(e).isInstanceOf(ExecutionException.class);
-      assertThat(e).hasCauseThat().isSameInstanceAs(ex);
-    }
-    assertThat(receiver.getBatches()).hasSize(1);
-
-    List<List<Integer>> expected = Arrays.asList(Arrays.asList(3));
-    List<List<Integer>> actual = new ArrayList<>();
-    for (SimpleBatch batch : receiver.getBatches()) {
-      actual.add(batch.getIntegers());
-    }
-    assertThat(actual).isEqualTo(expected);
-
-    assertThat(trackedFlowController.getElementsReserved())
-        .isEqualTo(trackedFlowController.getElementsReleased());
-    assertThat(trackedFlowController.getBytesReserved())
-        .isEqualTo(trackedFlowController.getBytesReleased());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/batching/TrackedFlowController.java b/gax/src/test/java/com/google/api/gax/batching/TrackedFlowController.java
deleted file mode 100644
index 567e6f29c..000000000
--- a/gax/src/test/java/com/google/api/gax/batching/TrackedFlowController.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.batching;
-
-/**
- * An extension of FlowController that tracks the number of permits and calls to reserve and release
- */
-public class TrackedFlowController extends FlowController {
-  private long elementsReserved = 0;
-  private long elementsReleased = 0;
-  private long bytesReserved = 0;
-  private long bytesReleased = 0;
-  private int callsToReserve = 0;
-  private int callsToRelease = 0;
-
-  public TrackedFlowController(FlowControlSettings settings) {
-    super(settings);
-  }
-
-  @Override
-  public void reserve(long elements, long bytes) throws FlowControlException {
-    super.reserve(elements, bytes);
-    this.elementsReserved += elements;
-    this.bytesReserved += bytes;
-    this.callsToReserve += 1;
-  }
-
-  @Override
-  public void release(long elements, long bytes) {
-    super.release(elements, bytes);
-    this.elementsReleased += elements;
-    this.bytesReleased += bytes;
-    this.callsToRelease += 1;
-  }
-
-  public long getElementsReserved() {
-    return elementsReserved;
-  }
-
-  public long getElementsReleased() {
-    return elementsReleased;
-  }
-
-  public long getBytesReserved() {
-    return bytesReserved;
-  }
-
-  public long getBytesReleased() {
-    return bytesReleased;
-  }
-
-  public int getCallsToReserve() {
-    return callsToReserve;
-  }
-
-  public int getCallsToRelease() {
-    return callsToRelease;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/core/DistributionTest.java b/gax/src/test/java/com/google/api/gax/core/DistributionTest.java
deleted file mode 100644
index 7e6cb8a6a..000000000
--- a/gax/src/test/java/com/google/api/gax/core/DistributionTest.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import java.util.Arrays;
-import java.util.Collections;
-import org.junit.Test;
-
-public class DistributionTest {
-  @Test
-  public void testPercentile() {
-    // These tests come from examples in
-    // https://en.wikipedia.org/wiki/Percentile#The_nearest-rank_method
-    Distribution dist;
-
-    dist = of(15, 20, 35, 40, 50);
-    assertThat(dist.getPercentile(5)).isEqualTo(15);
-    assertThat(dist.getPercentile(30)).isEqualTo(20);
-    assertThat(dist.getPercentile(40)).isEqualTo(20);
-    assertThat(dist.getPercentile(50)).isEqualTo(35);
-    assertThat(dist.getPercentile(100)).isEqualTo(50);
-
-    dist = of(3, 6, 7, 8, 8, 10, 13, 15, 16, 20);
-    assertThat(dist.getPercentile(25)).isEqualTo(7);
-    assertThat(dist.getPercentile(50)).isEqualTo(8);
-    assertThat(dist.getPercentile(75)).isEqualTo(15);
-    assertThat(dist.getPercentile(100)).isEqualTo(20);
-
-    dist = of(3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20);
-    assertThat(dist.getPercentile(25)).isEqualTo(7);
-    assertThat(dist.getPercentile(50)).isEqualTo(9);
-    assertThat(dist.getPercentile(75)).isEqualTo(15);
-    assertThat(dist.getPercentile(100)).isEqualTo(20);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testZeroMaxValue() {
-    new Distribution(0);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testNegativeMaxValue() {
-    new Distribution(-1);
-  }
-
-  @Test
-  public void testOverflowMaxValue() {
-    // Record value greater than maxValue-1 is OK. We record maxValue-1 instead.
-    Distribution dist = new Distribution(10);
-    dist.record(10);
-    assertThat(dist.getPercentile(100)).isEqualTo(9);
-  }
-
-  private Distribution of(Integer... values) {
-    int max = Collections.max(Arrays.asList(values));
-    Distribution dist = new Distribution(max + 1);
-    for (int value : values) {
-      dist.record(value);
-    }
-    return dist;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/core/FakeApiClock.java b/gax/src/test/java/com/google/api/gax/core/FakeApiClock.java
deleted file mode 100644
index 087fbf1ec..000000000
--- a/gax/src/test/java/com/google/api/gax/core/FakeApiClock.java
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import com.google.api.core.ApiClock;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicLong;
-
-public class FakeApiClock implements ApiClock {
-  private final AtomicLong currentNanoTime;
-
-  public FakeApiClock(long initialNanoTime) {
-    currentNanoTime = new AtomicLong(initialNanoTime);
-  }
-
-  @Override
-  public long nanoTime() {
-    return currentNanoTime.get();
-  }
-
-  @Override
-  public long millisTime() {
-    return TimeUnit.MILLISECONDS.convert(nanoTime(), TimeUnit.NANOSECONDS);
-  }
-
-  public void incrementNanoTime(long delta) {
-    currentNanoTime.getAndAdd(delta);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/core/GaxPropertiesTest.java b/gax/src/test/java/com/google/api/gax/core/GaxPropertiesTest.java
deleted file mode 100644
index 27d942e69..000000000
--- a/gax/src/test/java/com/google/api/gax/core/GaxPropertiesTest.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import static org.graalvm.nativeimage.ImageInfo.PROPERTY_IMAGE_CODE_KEY;
-import static org.graalvm.nativeimage.ImageInfo.PROPERTY_IMAGE_CODE_VALUE_RUNTIME;
-import static org.junit.Assert.assertTrue;
-
-import java.util.regex.Pattern;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class GaxPropertiesTest {
-
-  @Test
-  public void testGaxVersion() {
-    String gaxVersion = GaxProperties.getGaxVersion();
-    assertTrue(Pattern.compile("^\\d+\\.\\d+\\.\\d+").matcher(gaxVersion).find());
-    String[] versionComponents = gaxVersion.split("\\.");
-    // This test was added in version 1.56.0, so check that the major and minor numbers are greater
-    // than that.
-    int major = Integer.parseInt(versionComponents[0]);
-    int minor = Integer.parseInt(versionComponents[1]);
-
-    assertTrue(major >= 1);
-    if (major == 1) {
-      assertTrue(minor >= 56);
-    }
-  }
-
-  @Test
-  public void testGetVersion_nativeImage() {
-    System.setProperty(PROPERTY_IMAGE_CODE_KEY, PROPERTY_IMAGE_CODE_VALUE_RUNTIME);
-    String javaVersion = GaxProperties.getJavaVersion();
-    assertTrue(javaVersion.endsWith("-graalvm"));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/core/GoogleCredentialsProviderTest.java b/gax/src/test/java/com/google/api/gax/core/GoogleCredentialsProviderTest.java
deleted file mode 100644
index 9cea58f6a..000000000
--- a/gax/src/test/java/com/google/api/gax/core/GoogleCredentialsProviderTest.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertTrue;
-
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.ServiceAccountCredentials;
-import com.google.auth.oauth2.ServiceAccountJwtAccessCredentials;
-import com.google.common.collect.ImmutableList;
-import java.security.PrivateKey;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class GoogleCredentialsProviderTest {
-  ServiceAccountCredentials CreateServiceAccountCredentials() {
-    return ServiceAccountCredentials.newBuilder()
-        .setClientId("fake-client-id")
-        .setClientEmail("fake@example.com")
-        .setPrivateKeyId("fake-private-key")
-        .setPrivateKey(Mockito.mock(PrivateKey.class))
-        .build();
-  }
-
-  @Test
-  public void serviceAccountReplacedWithJwtTokens() throws Exception {
-    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
-
-    GoogleCredentialsProvider provider =
-        GoogleCredentialsProvider.newBuilder()
-            .setScopesToApply(ImmutableList.of("scope1", "scope2"))
-            .setJwtEnabledScopes(ImmutableList.of("scope1"))
-            .setOAuth2Credentials(serviceAccountCredentials)
-            .build();
-
-    Credentials credentials = provider.getCredentials();
-    assertThat(credentials).isInstanceOf(ServiceAccountJwtAccessCredentials.class);
-    ServiceAccountJwtAccessCredentials jwtCreds = (ServiceAccountJwtAccessCredentials) credentials;
-    assertThat(jwtCreds.getClientId()).isEqualTo(serviceAccountCredentials.getClientId());
-    assertThat(jwtCreds.getClientEmail()).isEqualTo(serviceAccountCredentials.getClientEmail());
-    assertThat(jwtCreds.getPrivateKeyId()).isEqualTo(serviceAccountCredentials.getPrivateKeyId());
-    assertThat(jwtCreds.getPrivateKey()).isEqualTo(serviceAccountCredentials.getPrivateKey());
-  }
-
-  @Test
-  public void noJwtWithoutScopeMatch() throws Exception {
-    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
-
-    GoogleCredentialsProvider provider =
-        GoogleCredentialsProvider.newBuilder()
-            .setScopesToApply(ImmutableList.of("scope1", "scope2"))
-            .setJwtEnabledScopes(ImmutableList.of("other"))
-            .setOAuth2Credentials(serviceAccountCredentials)
-            .build();
-
-    Credentials credentials = provider.getCredentials();
-    assertThat(credentials).isInstanceOf(ServiceAccountCredentials.class);
-
-    ServiceAccountCredentials serviceAccountCredentials2 = (ServiceAccountCredentials) credentials;
-    assertThat(serviceAccountCredentials2.getClientId())
-        .isEqualTo(serviceAccountCredentials.getClientId());
-    assertThat(serviceAccountCredentials2.getClientEmail())
-        .isEqualTo(serviceAccountCredentials.getClientEmail());
-    assertThat(serviceAccountCredentials2.getPrivateKeyId())
-        .isEqualTo(serviceAccountCredentials.getPrivateKeyId());
-    assertThat(serviceAccountCredentials2.getPrivateKey())
-        .isEqualTo(serviceAccountCredentials.getPrivateKey());
-    assertThat(serviceAccountCredentials2.getScopes()).containsExactly("scope1", "scope2");
-  }
-
-  @Test
-  public void useJwtAccessWithScope() throws Exception {
-    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
-
-    GoogleCredentialsProvider provider =
-        GoogleCredentialsProvider.newBuilder()
-            .setScopesToApply(ImmutableList.of("scope1", "scope2"))
-            .setOAuth2Credentials(serviceAccountCredentials)
-            .setUseJwtAccessWithScope(true)
-            .build();
-
-    Credentials credentials = provider.getCredentials();
-    assertThat(credentials).isInstanceOf(ServiceAccountCredentials.class);
-
-    ServiceAccountCredentials serviceAccountCredentials2 = (ServiceAccountCredentials) credentials;
-    assertThat(serviceAccountCredentials2.getClientId())
-        .isEqualTo(serviceAccountCredentials.getClientId());
-    assertThat(serviceAccountCredentials2.getClientEmail())
-        .isEqualTo(serviceAccountCredentials.getClientEmail());
-    assertThat(serviceAccountCredentials2.getPrivateKeyId())
-        .isEqualTo(serviceAccountCredentials.getPrivateKeyId());
-    assertThat(serviceAccountCredentials2.getPrivateKey())
-        .isEqualTo(serviceAccountCredentials.getPrivateKey());
-    assertTrue(serviceAccountCredentials2.getUseJwtAccessWithScope());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/core/RecordingScheduler.java b/gax/src/test/java/com/google/api/gax/core/RecordingScheduler.java
deleted file mode 100644
index 6d8cf9119..000000000
--- a/gax/src/test/java/com/google/api/gax/core/RecordingScheduler.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.core;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyLong;
-import static org.mockito.Mockito.when;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-import org.mockito.Mockito;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
-import org.threeten.bp.Duration;
-
-public abstract class RecordingScheduler implements ScheduledExecutorService {
-
-  public abstract List<Duration> getSleepDurations();
-
-  public abstract int getIterationsCount();
-
-  public static RecordingScheduler create(final FakeApiClock clock) {
-    RecordingScheduler mock = Mockito.mock(RecordingScheduler.class);
-
-    // mock class fields:
-    final ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-    final List<Duration> sleepDurations = new ArrayList<>();
-    final AtomicInteger iterationsCount = new AtomicInteger(0);
-
-    // mock class methods:
-    // ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);
-    when(mock.schedule(any(Runnable.class), anyLong(), any(TimeUnit.class)))
-        .then(
-            new Answer<ScheduledFuture<?>>() {
-              @Override
-              public ScheduledFuture<?> answer(InvocationOnMock invocation) throws Throwable {
-                Object[] args = invocation.getArguments();
-                Runnable runnable = (Runnable) args[0];
-                Long delay = (Long) args[1];
-                TimeUnit unit = (TimeUnit) args[2];
-                iterationsCount.incrementAndGet();
-                sleepDurations.add(Duration.ofMillis(TimeUnit.MILLISECONDS.convert(delay, unit)));
-                clock.incrementNanoTime(TimeUnit.NANOSECONDS.convert(delay, unit));
-                return executor.schedule(runnable, 0, TimeUnit.NANOSECONDS);
-              }
-            });
-
-    // List<Runnable> shutdownNow()
-    when(mock.shutdownNow())
-        .then(
-            new Answer<List<Runnable>>() {
-              @Override
-              public List<Runnable> answer(InvocationOnMock invocation) throws Throwable {
-                return executor.shutdownNow();
-              }
-            });
-
-    // List<Duration> getSleepDurations()
-    when(mock.getSleepDurations()).thenReturn(sleepDurations);
-
-    // int getIterationsCount()
-    when(mock.getIterationsCount())
-        .then(
-            new Answer<Integer>() {
-              @Override
-              public Integer answer(InvocationOnMock invocation) throws Throwable {
-                return iterationsCount.get();
-              }
-            });
-
-    return mock;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/longrunning/OperationFuturesTest.java b/gax/src/test/java/com/google/api/gax/longrunning/OperationFuturesTest.java
deleted file mode 100644
index 9b9ea96a5..000000000
--- a/gax/src/test/java/com/google/api/gax/longrunning/OperationFuturesTest.java
+++ /dev/null
@@ -1,179 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.longrunning;
-
-import static com.google.common.truth.Truth.assertThat;
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-import static org.junit.Assert.fail;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeOperationSnapshot;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import org.junit.Test;
-
-public class OperationFuturesTest {
-  @Test(expected = IllegalArgumentException.class)
-  public void testNotDone() {
-    OperationFutures.immediateOperationFuture(
-        FakeOperationSnapshot.newBuilder()
-            .setName("required")
-            .setDone(false)
-            .setErrorCode(FakeStatusCode.of(StatusCode.Code.OK))
-            .build());
-  }
-
-  @Test
-  public void testCompleted() throws Exception {
-    OperationFuture<String, Integer> future =
-        OperationFutures.<String, Integer>immediateOperationFuture(
-            FakeOperationSnapshot.newBuilder()
-                .setName("myName")
-                .setDone(true)
-                .setResponse("theResponse")
-                .setMetadata(42)
-                .setErrorCode(FakeStatusCode.of(StatusCode.Code.OK))
-                .build());
-    assertThat(future.getName()).isEqualTo("myName");
-    assertThat(future.get()).isEqualTo("theResponse");
-    assertThat(future.getMetadata().get()).isEqualTo(42);
-  }
-
-  @Test
-  public void testFailed() throws Exception {
-    OperationFuture<String, Integer> future =
-        OperationFutures.<String, Integer>immediateOperationFuture(
-            FakeOperationSnapshot.newBuilder()
-                .setName("myName")
-                .setDone(true)
-                .setMetadata(42)
-                .setErrorCode(FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT))
-                .build());
-    assertThat(future.getName()).isEqualTo("myName");
-    assertThat(future.getMetadata().get()).isEqualTo(42);
-    try {
-      future.get();
-      fail();
-    } catch (ExecutionException e) {
-      assertThat(e.getCause()).isInstanceOf(ApiException.class);
-    }
-  }
-
-  @Test
-  public void testTransform() throws Exception {
-    // Test dependencies.
-    MockRetryingFuture<OperationSnapshot> pollingFuture = new MockRetryingFuture<>();
-    SettableApiFuture<OperationSnapshot> initialFuture = SettableApiFuture.create();
-    ApiFunction<OperationSnapshot, String> responseTransform =
-        new ApiFunction<OperationSnapshot, String>() {
-          @Override
-          public String apply(OperationSnapshot operationSnapshot) {
-            return (String) operationSnapshot.getResponse();
-          }
-        };
-    ApiFunction<OperationSnapshot, Integer> metadataTransform =
-        new ApiFunction<OperationSnapshot, Integer>() {
-          @Override
-          public Integer apply(OperationSnapshot operationSnapshot) {
-            return (int) operationSnapshot.getMetadata();
-          }
-        };
-
-    pollingFuture.set(
-        FakeOperationSnapshot.newBuilder()
-            .setName("my-name")
-            .setDone(true)
-            .setErrorCode(FakeStatusCode.of(Code.OK))
-            .setResponse("response")
-            .build());
-
-    // Subject of the test.
-    OperationFuture<String, Integer> future =
-        new OperationFutureImpl<>(
-            pollingFuture, initialFuture, responseTransform, metadataTransform);
-
-    // Actual test: make sure that ApiFutures can chain off the result.
-    ApiFuture<String> transformedFuture =
-        ApiFutures.transform(
-            future,
-            new ApiFunction<String, String>() {
-              @Override
-              public String apply(String s) {
-                return "transformed: " + s;
-              }
-            },
-            directExecutor());
-
-    assertThat(transformedFuture.get(1, TimeUnit.SECONDS)).isEqualTo("transformed: response");
-  }
-
-  private static class MockRetryingFuture<ResponseT> extends AbstractApiFuture<ResponseT>
-      implements RetryingFuture<ResponseT> {
-    public boolean set(ResponseT value) {
-      return super.set(value);
-    }
-
-    @Override
-    public void setAttemptFuture(ApiFuture<ResponseT> attemptFuture) {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public Callable<ResponseT> getCallable() {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public TimedAttemptSettings getAttemptSettings() {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ApiFuture<ResponseT> peekAttemptResult() {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ApiFuture<ResponseT> getAttemptResult() {
-      throw new UnsupportedOperationException();
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/paging/PagesTest.java b/gax/src/test/java/com/google/api/gax/paging/PagesTest.java
deleted file mode 100644
index 8bf7d5bfb..000000000
--- a/gax/src/test/java/com/google/api/gax/paging/PagesTest.java
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.paging;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import org.junit.Test;
-
-public class PagesTest {
-  @Test
-  public void testEmpty() {
-    assertThat(Pages.<Integer>empty().iterateAll()).isEmpty();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/AbstractRetryingExecutorTest.java b/gax/src/test/java/com/google/api/gax/retrying/AbstractRetryingExecutorTest.java
deleted file mode 100644
index e376a7c7a..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/AbstractRetryingExecutorTest.java
+++ /dev/null
@@ -1,478 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.api.gax.retrying.FailingCallable.FAILING_RETRY_SETTINGS;
-import static com.google.api.gax.retrying.FailingCallable.FAST_RETRY_SETTINGS;
-import static junit.framework.TestCase.assertFalse;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.anyInt;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.retrying.FailingCallable.CustomException;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.common.base.Stopwatch;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import java.util.concurrent.atomic.AtomicInteger;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.Parameterized;
-import org.junit.runners.Parameterized.Parameter;
-import org.junit.runners.Parameterized.Parameters;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.threeten.bp.Duration;
-
-@RunWith(Parameterized.class)
-public abstract class AbstractRetryingExecutorTest {
-
-  @Parameters(name = "Custom retry settings: {0}")
-  public static Collection<Object[]> data() {
-    return Arrays.asList(new Object[][] {{false}, {true}});
-  }
-
-  @Parameter public boolean withCustomRetrySettings;
-
-  @Rule public final MockitoRule mockitoRule = MockitoJUnit.rule();
-
-  @Mock protected ApiTracer tracer;
-  protected RetryingContext retryingContext;
-
-  protected abstract RetryingExecutorWithContext<String> getExecutor(
-      RetryAlgorithm<String> retryAlgorithm);
-
-  protected abstract RetryAlgorithm<String> getAlgorithm(
-      RetrySettings retrySettings, int apocalypseCountDown, RuntimeException apocalypseException);
-
-  protected <T> void busyWaitForInitialResult(RetryingFuture<T> future, Duration timeout)
-      throws TimeoutException {
-    Stopwatch watch = Stopwatch.createStarted();
-    while (future.peekAttemptResult() == null) {
-      if (watch.elapsed(TimeUnit.NANOSECONDS) > timeout.toNanos()) {
-        throw new TimeoutException();
-      }
-    }
-  }
-
-  @Before
-  public void setUp() {
-    if (withCustomRetrySettings) {
-      retryingContext =
-          FakeCallContext.createDefault().withTracer(tracer).withRetrySettings(FAST_RETRY_SETTINGS);
-    } else {
-      retryingContext = FakeCallContext.createDefault().withTracer(tracer);
-    }
-  }
-
-  private RetrySettings getDefaultRetrySettings() {
-    return withCustomRetrySettings ? FAILING_RETRY_SETTINGS : FAST_RETRY_SETTINGS;
-  }
-
-  @Test
-  public void testSuccess() throws Exception {
-    FailingCallable callable = new FailingCallable(0, "request", "SUCCESS", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 0, null));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureSuccess(future);
-    assertEquals(0, future.getAttemptSettings().getAttemptCount());
-
-    verify(tracer, times(1)).attemptStarted(eq("request"), eq(0));
-    verify(tracer, times(1)).attemptSucceeded();
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testSuccessWithFailures() throws Exception {
-    FailingCallable callable = new FailingCallable(5, "request", "SUCCESS", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 0, null));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureSuccess(future);
-    assertEquals(5, future.getAttemptSettings().getAttemptCount());
-
-    verify(tracer, times(6)).attemptStarted(eq("request"), anyInt());
-    verify(tracer, times(5)).attemptFailed(any(Throwable.class), any(Duration.class));
-    verify(tracer, times(1)).attemptSucceeded();
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testSuccessWithFailuresPeekGetAttempt() throws Exception {
-    FailingCallable callable = new FailingCallable(5, "request", "SUCCESS", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 0, null));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-
-    assertNull(future.peekAttemptResult());
-    assertSame(future.peekAttemptResult(), future.peekAttemptResult());
-    assertFalse(future.getAttemptResult().isDone());
-    assertFalse(future.getAttemptResult().isCancelled());
-
-    Exception exception = null;
-    try {
-      future.get(1L, TimeUnit.MILLISECONDS);
-    } catch (TimeoutException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureSuccess(future);
-    assertEquals(5, future.getAttemptSettings().getAttemptCount());
-  }
-
-  @Test
-  public void testMaxRetriesExceeded() throws Exception {
-    FailingCallable callable = new FailingCallable(6, "request", "FAILURE", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 0, null));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureFail(future, CustomException.class);
-    assertEquals(5, future.getAttemptSettings().getAttemptCount());
-
-    verify(tracer, times(6)).attemptStarted(eq("request"), anyInt());
-    verify(tracer, times(5)).attemptFailed(any(Throwable.class), any(Duration.class));
-    verify(tracer, times(1)).attemptFailedRetriesExhausted(any(Throwable.class));
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testTotalTimeoutExceeded() throws Exception {
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .setMaxRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .build();
-    boolean useContextRetrySettings = retryingContext.getRetrySettings() != null;
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(
-            getAlgorithm(
-                useContextRetrySettings ? getDefaultRetrySettings() : retrySettings, 0, null));
-    FailingCallable callable = new FailingCallable(6, "request", "FAILURE", tracer);
-    RetryingContext context;
-    if (useContextRetrySettings) {
-      context = FakeCallContext.createDefault().withTracer(tracer).withRetrySettings(retrySettings);
-    } else {
-      context = FakeCallContext.createDefault().withTracer(tracer);
-    }
-    RetryingFuture<String> future = executor.createFuture(callable, context);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureFail(future, CustomException.class);
-    assertTrue(future.getAttemptSettings().getAttemptCount() < 4);
-
-    verify(tracer, times(1)).attemptStarted(eq("request"), anyInt());
-    verify(tracer, times(1)).attemptFailedRetriesExhausted(any(Throwable.class));
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testCancelOuterFutureBeforeStart() throws Exception {
-    FailingCallable callable = new FailingCallable(4, "request", "SUCCESS", tracer);
-
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(1_000L))
-            .setMaxRetryDelay(Duration.ofMillis(1_000L))
-            .setTotalTimeout(Duration.ofMillis(10_0000L))
-            .build();
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(retrySettings, 0, null));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    boolean res = future.cancel(false);
-
-    assertTrue(res);
-
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureCancel(future);
-    assertEquals(0, future.getAttemptSettings().getAttemptCount());
-
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testCancelByRetryingAlgorithm() throws Exception {
-    FailingCallable callable = new FailingCallable(6, "request", "FAILURE", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 5, new CancellationException()));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureCancel(future);
-    assertEquals(4, future.getAttemptSettings().getAttemptCount());
-
-    verify(tracer, times(5)).attemptStarted(eq("request"), anyInt());
-    // Pre-apocalypse failures
-    verify(tracer, times(4)).attemptFailed(any(Throwable.class), any(Duration.class));
-    // Apocalypse failure
-    verify(tracer, times(1)).attemptFailedRetriesExhausted(any(CancellationException.class));
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testUnexpectedExceptionFromRetryAlgorithm() throws Exception {
-    FailingCallable callable = new FailingCallable(6, "request", "FAILURE", tracer);
-    RetryingExecutorWithContext<String> executor =
-        getExecutor(getAlgorithm(getDefaultRetrySettings(), 5, new RuntimeException()));
-    RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureFail(future, RuntimeException.class);
-    assertEquals(4, future.getAttemptSettings().getAttemptCount());
-
-    verify(tracer, times(5)).attemptStarted(eq("request"), anyInt());
-    // Pre-apocalypse failures
-    verify(tracer, times(4)).attemptFailed(any(Throwable.class), any(Duration.class));
-    // Apocalypse failure
-    verify(tracer, times(1)).attemptPermanentFailure(any(RuntimeException.class));
-    verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testPollExceptionByPollAlgorithm() throws Exception {
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .setMaxRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .build();
-    boolean useContextRetrySettings = retryingContext.getRetrySettings() != null;
-
-    RetryAlgorithm<String> retryAlgorithm =
-        new RetryAlgorithm<>(
-            new TestResultRetryAlgorithm<String>(0, null),
-            new ExponentialPollAlgorithm(
-                useContextRetrySettings ? getDefaultRetrySettings() : retrySettings,
-                NanoClock.getDefaultClock()));
-
-    RetryingExecutorWithContext<String> executor = getExecutor(retryAlgorithm);
-    FailingCallable callable = new FailingCallable(6, "request", "FAILURE", tracer);
-    RetryingContext context;
-    if (useContextRetrySettings) {
-      context = FakeCallContext.createDefault().withTracer(tracer).withRetrySettings(retrySettings);
-    } else {
-      context = FakeCallContext.createDefault().withTracer(tracer);
-    }
-    RetryingFuture<String> future = executor.createFuture(callable, context);
-    future.setAttemptFuture(executor.submit(future));
-
-    assertFutureFail(future, PollException.class);
-    assertTrue(future.getAttemptSettings().getAttemptCount() < 4);
-
-    verify(tracer, times(1)).attemptStarted(eq("request"), anyInt());
-    verify(tracer, times(1)).attemptPermanentFailure(any(PollException.class));
-    verifyNoMoreInteractions(tracer);
-  }
-
-  protected static class TestResultRetryAlgorithm<ResponseT>
-      extends BasicResultRetryAlgorithm<ResponseT> {
-    private AtomicInteger apocalypseCountDown;
-    private RuntimeException apocalypseException;
-
-    TestResultRetryAlgorithm(int apocalypseCountDown, RuntimeException apocalypseException) {
-      this.apocalypseCountDown =
-          apocalypseCountDown > 0
-              ? new AtomicInteger(apocalypseCountDown * 2)
-              : new AtomicInteger(Integer.MAX_VALUE);
-      this.apocalypseException = apocalypseException;
-    }
-
-    @Override
-    public boolean shouldRetry(Throwable prevThrowable, ResponseT prevResponse) {
-      if (apocalypseCountDown.decrementAndGet() == 0) {
-        throw apocalypseException;
-      }
-      return super.shouldRetry(prevThrowable, prevResponse);
-    }
-  }
-
-  void assertFutureSuccess(RetryingFuture<String> future)
-      throws ExecutionException, InterruptedException, TimeoutException {
-    assertEquals("SUCCESS", future.get(3, TimeUnit.SECONDS));
-    assertTrue(future.isDone());
-    assertFalse(future.isCancelled());
-
-    assertEquals("SUCCESS", future.peekAttemptResult().get(3, TimeUnit.SECONDS));
-    assertSame(future.peekAttemptResult(), future.peekAttemptResult());
-    assertTrue(future.peekAttemptResult().isDone());
-    assertFalse(future.peekAttemptResult().isCancelled());
-
-    assertEquals("SUCCESS", future.getAttemptResult().get(3, TimeUnit.SECONDS));
-    assertSame(future.getAttemptResult(), future.getAttemptResult());
-    assertTrue(future.getAttemptResult().isDone());
-    assertFalse(future.getAttemptResult().isCancelled());
-
-    String res = future.get();
-    ApiFuture<?> gottentAttempt = future.getAttemptResult();
-    ApiFuture<?> peekedAttempt = future.peekAttemptResult();
-
-    // testing completed immutability
-    assertFalse(future.cancel(true));
-    assertFalse(future.cancel(false));
-    assertSame(gottentAttempt, future.getAttemptResult());
-    assertSame(peekedAttempt, future.peekAttemptResult());
-    assertSame(res, future.get());
-    assertTrue(future.isDone());
-    assertFalse(future.isCancelled());
-  }
-
-  void assertFutureFail(RetryingFuture<?> future, Class<? extends Throwable> exceptionClass)
-      throws TimeoutException, InterruptedException {
-    Throwable exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e.getCause();
-    }
-    assertNotNull(exception);
-    assertEquals(exception.getClass(), exceptionClass);
-    assertTrue(future.isDone());
-    assertFalse(future.isCancelled());
-
-    try {
-      future.peekAttemptResult().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e.getCause();
-    }
-    assertNotNull(exception);
-    assertEquals(exception.getClass(), exceptionClass);
-    assertSame(future.peekAttemptResult(), future.peekAttemptResult());
-    assertTrue(future.peekAttemptResult().isDone());
-    assertFalse(future.peekAttemptResult().isCancelled());
-
-    try {
-      future.getAttemptResult().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e.getCause();
-    }
-    assertNotNull(exception);
-    assertEquals(exception.getClass(), exceptionClass);
-    assertSame(future.getAttemptResult(), future.getAttemptResult());
-    assertTrue(future.getAttemptResult().isDone());
-    assertFalse(future.getAttemptResult().isCancelled());
-
-    ApiFuture<?> gottentAttempt = future.getAttemptResult();
-    ApiFuture<?> peekedAttempt = future.peekAttemptResult();
-
-    // testing completed immutability
-    assertFalse(future.cancel(true));
-    assertFalse(future.cancel(false));
-    assertSame(gottentAttempt, future.getAttemptResult());
-    assertSame(peekedAttempt, future.peekAttemptResult());
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e.getCause();
-    }
-    assertNotNull(exception);
-    assertEquals(exception.getClass(), exceptionClass);
-    assertTrue(future.isDone());
-    assertFalse(future.isCancelled());
-  }
-
-  void assertFutureCancel(RetryingFuture<?> future)
-      throws ExecutionException, InterruptedException, TimeoutException {
-    Exception exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-    assertTrue(future.isDone());
-    assertTrue(future.isCancelled());
-
-    try {
-      future.getAttemptResult().get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-    assertSame(future.getAttemptResult(), future.getAttemptResult());
-    assertTrue(future.getAttemptResult().isDone());
-    assertTrue(future.getAttemptResult().isCancelled());
-    try {
-      future.peekAttemptResult().get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-    assertSame(future.peekAttemptResult(), future.peekAttemptResult());
-    assertTrue(future.peekAttemptResult().isDone());
-    assertTrue(future.peekAttemptResult().isCancelled());
-
-    ApiFuture<?> gottentAttempt = future.getAttemptResult();
-    ApiFuture<?> peekedAttempt = future.peekAttemptResult();
-
-    // testing completed immutability
-    assertFalse(future.cancel(true));
-    assertFalse(future.cancel(false));
-    assertSame(gottentAttempt, future.getAttemptResult());
-    assertSame(peekedAttempt, future.peekAttemptResult());
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-    assertTrue(future.isDone());
-    assertTrue(future.isCancelled());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/BasicRetryingFutureTest.java b/gax/src/test/java/com/google/api/gax/retrying/BasicRetryingFutureTest.java
deleted file mode 100644
index c95cda7eb..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/BasicRetryingFutureTest.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static org.mockito.Mockito.mock;
-
-import com.google.api.gax.tracing.ApiTracer;
-import java.lang.reflect.Field;
-import java.util.concurrent.Callable;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentMatchers;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BasicRetryingFutureTest {
-  private Level logLevel;
-
-  @Before
-  public void setUp() throws Exception {
-    logLevel = getLoggerInstance().getLevel();
-  }
-
-  @After
-  public void tearDown() throws Exception {
-    getLoggerInstance().setLevel(logLevel);
-  }
-
-  @Test
-  public void testHandleAttemptDoesNotThrowNPEWhenLogLevelLowerThanFiner() throws Exception {
-    @SuppressWarnings("unchecked")
-    Callable<Integer> callable = mock(Callable.class);
-    @SuppressWarnings("unchecked")
-    RetryAlgorithm<Integer> retryAlgorithm = mock(RetryAlgorithm.class);
-    RetryingContext retryingContext = mock(RetryingContext.class);
-    ApiTracer tracer = mock(ApiTracer.class);
-    TimedAttemptSettings timedAttemptSettings = mock(TimedAttemptSettings.class);
-
-    Mockito.when(retryingContext.getTracer()).thenReturn(tracer);
-
-    Mockito.when(retryAlgorithm.createFirstAttempt(ArgumentMatchers.<RetryingContext>any()))
-        .thenReturn(timedAttemptSettings);
-    Mockito.when(
-            retryAlgorithm.createNextAttempt(
-                ArgumentMatchers.<RetryingContext>any(),
-                ArgumentMatchers.<Throwable>any(),
-                ArgumentMatchers.<Integer>any(),
-                ArgumentMatchers.<TimedAttemptSettings>any()))
-        .thenReturn(timedAttemptSettings);
-    Mockito.when(
-            retryAlgorithm.shouldRetry(
-                ArgumentMatchers.<RetryingContext>any(),
-                ArgumentMatchers.<Throwable>any(),
-                ArgumentMatchers.<Integer>any(),
-                ArgumentMatchers.<TimedAttemptSettings>any()))
-        .thenReturn(true);
-
-    getLoggerInstance().setLevel(Level.FINEST);
-
-    BasicRetryingFuture<Integer> future =
-        new BasicRetryingFuture<>(callable, retryAlgorithm, retryingContext);
-
-    future.handleAttempt(null, null);
-
-    Mockito.verify(tracer)
-        .attemptFailed(ArgumentMatchers.<Throwable>any(), ArgumentMatchers.<Duration>any());
-    Mockito.verifyNoMoreInteractions(tracer);
-  }
-
-  @Test
-  public void testUsesRetryingContext() throws Exception {
-    @SuppressWarnings("unchecked")
-    Callable<Integer> callable = mock(Callable.class);
-    @SuppressWarnings("unchecked")
-    RetryAlgorithm<Integer> retryAlgorithm = mock(RetryAlgorithm.class);
-    RetryingContext retryingContext = mock(RetryingContext.class);
-    ApiTracer tracer = mock(ApiTracer.class);
-    TimedAttemptSettings timedAttemptSettings = mock(TimedAttemptSettings.class);
-    Mockito.when(retryingContext.getTracer()).thenReturn(tracer);
-
-    Mockito.when(retryAlgorithm.createFirstAttempt(retryingContext))
-        .thenReturn(timedAttemptSettings);
-    Mockito.when(
-            retryAlgorithm.createNextAttempt(
-                ArgumentMatchers.eq(retryingContext),
-                ArgumentMatchers.<Throwable>any(),
-                ArgumentMatchers.<Integer>any(),
-                ArgumentMatchers.<TimedAttemptSettings>any()))
-        .thenReturn(timedAttemptSettings);
-    Mockito.when(
-            retryAlgorithm.shouldRetry(
-                ArgumentMatchers.eq(retryingContext),
-                ArgumentMatchers.<Throwable>any(),
-                ArgumentMatchers.<Integer>any(),
-                ArgumentMatchers.<TimedAttemptSettings>any()))
-        .thenReturn(true);
-
-    BasicRetryingFuture<Integer> future =
-        new BasicRetryingFuture<>(callable, retryAlgorithm, retryingContext);
-
-    future.handleAttempt(null, null);
-
-    Mockito.verify(retryAlgorithm).createFirstAttempt(retryingContext);
-    Mockito.verify(retryAlgorithm)
-        .createNextAttempt(
-            ArgumentMatchers.eq(retryingContext),
-            ArgumentMatchers.<Throwable>any(),
-            ArgumentMatchers.<Integer>any(),
-            ArgumentMatchers.<TimedAttemptSettings>any());
-    Mockito.verify(retryAlgorithm)
-        .shouldRetry(
-            ArgumentMatchers.eq(retryingContext),
-            ArgumentMatchers.<Throwable>any(),
-            ArgumentMatchers.<Integer>any(),
-            ArgumentMatchers.<TimedAttemptSettings>any());
-    Mockito.verifyNoMoreInteractions(retryAlgorithm);
-  }
-
-  private Logger getLoggerInstance() throws NoSuchFieldException, IllegalAccessException {
-    Field logger = BasicRetryingFuture.class.getDeclaredField("LOG");
-    logger.setAccessible(true);
-
-    return (Logger) logger.get(BasicRetryingFuture.class);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/DirectRetryingExecutorTest.java b/gax/src/test/java/com/google/api/gax/retrying/DirectRetryingExecutorTest.java
deleted file mode 100644
index b8a990fbb..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/DirectRetryingExecutorTest.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.core.CurrentMillisClock;
-import org.junit.runner.RunWith;
-import org.mockito.junit.MockitoJUnitRunner;
-
-@RunWith(MockitoJUnitRunner.class)
-public class DirectRetryingExecutorTest extends AbstractRetryingExecutorTest {
-
-  @Override
-  protected RetryingExecutorWithContext<String> getExecutor(RetryAlgorithm<String> retryAlgorithm) {
-    return new DirectRetryingExecutor<>(retryAlgorithm);
-  }
-
-  @Override
-  protected RetryAlgorithm<String> getAlgorithm(
-      RetrySettings retrySettings, int apocalypseCountDown, RuntimeException apocalypseException) {
-    return new RetryAlgorithm<>(
-        new TestResultRetryAlgorithm<String>(apocalypseCountDown, apocalypseException),
-        new ExponentialRetryAlgorithm(retrySettings, CurrentMillisClock.getDefaultClock()));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/ExponentialRetryAlgorithmTest.java b/gax/src/test/java/com/google/api/gax/retrying/ExponentialRetryAlgorithmTest.java
deleted file mode 100644
index b81c8c95b..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/ExponentialRetryAlgorithmTest.java
+++ /dev/null
@@ -1,186 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class ExponentialRetryAlgorithmTest {
-  private final FakeApiClock clock = new FakeApiClock(0L);
-  private final RetrySettings retrySettings =
-      RetrySettings.newBuilder()
-          .setMaxAttempts(6)
-          .setInitialRetryDelay(Duration.ofMillis(1L))
-          .setRetryDelayMultiplier(2.0)
-          .setMaxRetryDelay(Duration.ofMillis(8L))
-          .setInitialRpcTimeout(Duration.ofMillis(1L))
-          .setRpcTimeoutMultiplier(2.0)
-          .setMaxRpcTimeout(Duration.ofMillis(8L))
-          .setTotalTimeout(Duration.ofMillis(200L))
-          .build();
-  private final ExponentialRetryAlgorithm algorithm =
-      new ExponentialRetryAlgorithm(retrySettings, clock);
-  private final RetrySettings retrySettingsOverride =
-      RetrySettings.newBuilder()
-          .setMaxAttempts(3)
-          .setInitialRetryDelay(Duration.ofMillis(2L))
-          .setRetryDelayMultiplier(3.0)
-          .setMaxRetryDelay(Duration.ofMillis(18L))
-          .setInitialRpcTimeout(Duration.ofMillis(2L))
-          .setRpcTimeoutMultiplier(3.0)
-          .setMaxRpcTimeout(Duration.ofMillis(18L))
-          .setTotalTimeout(Duration.ofMillis(300L))
-          .build();
-  private final RetryingContext retryingContext =
-      FakeCallContext.createDefault().withRetrySettings(retrySettingsOverride);
-
-  @Test
-  public void testCreateFirstAttempt() {
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt();
-
-    // Checking only the most core values, to not make this test too implementation specific.
-    assertEquals(0, attempt.getAttemptCount());
-    assertEquals(0, attempt.getOverallAttemptCount());
-    assertEquals(Duration.ZERO, attempt.getRetryDelay());
-    assertEquals(Duration.ZERO, attempt.getRandomizedRetryDelay());
-    assertEquals(Duration.ofMillis(1L), attempt.getRpcTimeout());
-    assertEquals(Duration.ZERO, attempt.getRetryDelay());
-  }
-
-  @Test
-  public void testCreateFirstAttemptOverride() {
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt(retryingContext);
-
-    // Checking only the most core values, to not make this test too implementation specific.
-    assertEquals(0, attempt.getAttemptCount());
-    assertEquals(0, attempt.getOverallAttemptCount());
-    assertEquals(Duration.ZERO, attempt.getRetryDelay());
-    assertEquals(Duration.ZERO, attempt.getRandomizedRetryDelay());
-    assertEquals(retrySettingsOverride.getInitialRpcTimeout(), attempt.getRpcTimeout());
-    assertEquals(Duration.ZERO, attempt.getRetryDelay());
-  }
-
-  @Test
-  public void testCreateNextAttempt() {
-    TimedAttemptSettings firstAttempt = algorithm.createFirstAttempt();
-    TimedAttemptSettings secondAttempt = algorithm.createNextAttempt(firstAttempt);
-
-    // Checking only the most core values, to not make this test too implementation specific.
-    assertEquals(1, secondAttempt.getAttemptCount());
-    assertEquals(1, secondAttempt.getOverallAttemptCount());
-    assertEquals(Duration.ofMillis(1L), secondAttempt.getRetryDelay());
-    assertEquals(Duration.ofMillis(2L), secondAttempt.getRpcTimeout());
-
-    TimedAttemptSettings thirdAttempt = algorithm.createNextAttempt(secondAttempt);
-    assertEquals(2, thirdAttempt.getAttemptCount());
-    assertEquals(Duration.ofMillis(2L), thirdAttempt.getRetryDelay());
-    assertEquals(Duration.ofMillis(4L), thirdAttempt.getRpcTimeout());
-  }
-
-  @Test
-  public void testCreateNextAttemptOverride() {
-    TimedAttemptSettings firstAttempt = algorithm.createFirstAttempt(retryingContext);
-    TimedAttemptSettings secondAttempt = algorithm.createNextAttempt(firstAttempt);
-
-    // Checking only the most core values, to not make this test too implementation specific.
-    assertEquals(1, secondAttempt.getAttemptCount());
-    assertEquals(1, secondAttempt.getOverallAttemptCount());
-    assertEquals(Duration.ofMillis(2L), secondAttempt.getRetryDelay());
-    assertEquals(Duration.ofMillis(6L), secondAttempt.getRpcTimeout());
-
-    TimedAttemptSettings thirdAttempt = algorithm.createNextAttempt(secondAttempt);
-    assertEquals(2, thirdAttempt.getAttemptCount());
-    assertEquals(Duration.ofMillis(6L), thirdAttempt.getRetryDelay());
-    assertEquals(Duration.ofMillis(18L), thirdAttempt.getRpcTimeout());
-  }
-
-  @Test
-  public void testTruncateToTotalTimeout() {
-    RetrySettings timeoutSettings =
-        retrySettings
-            .toBuilder()
-            .setInitialRpcTimeout(Duration.ofSeconds(4L))
-            .setMaxRpcTimeout(Duration.ofSeconds(4L))
-            .setTotalTimeout(Duration.ofSeconds(4L))
-            .build();
-    ExponentialRetryAlgorithm timeoutAlg = new ExponentialRetryAlgorithm(timeoutSettings, clock);
-
-    TimedAttemptSettings firstAttempt = timeoutAlg.createFirstAttempt();
-    TimedAttemptSettings secondAttempt = timeoutAlg.createNextAttempt(firstAttempt);
-    assertThat(secondAttempt.getRpcTimeout()).isAtLeast(firstAttempt.getRpcTimeout());
-    assertThat(secondAttempt.getRpcTimeout()).isAtMost(Duration.ofSeconds(4L));
-
-    TimedAttemptSettings thirdAttempt = timeoutAlg.createNextAttempt(secondAttempt);
-    assertThat(thirdAttempt.getRpcTimeout()).isAtMost(Duration.ofSeconds(4L));
-  }
-
-  @Test
-  public void testShouldRetryTrue() {
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt();
-    for (int i = 0; i < 2; i++) {
-      attempt = algorithm.createNextAttempt(attempt);
-    }
-
-    assertTrue(algorithm.shouldRetry(attempt));
-  }
-
-  @Test
-  public void testShouldRetryFalseOnMaxAttempts() {
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt();
-    for (int i = 0; i < 6; i++) {
-      assertTrue(algorithm.shouldRetry(attempt));
-      attempt = algorithm.createNextAttempt(attempt);
-    }
-
-    assertFalse(algorithm.shouldRetry(attempt));
-  }
-
-  @Test
-  public void testShouldRetryFalseOnMaxTimeout() {
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt();
-    for (int i = 0; i < 4; i++) {
-      assertTrue(algorithm.shouldRetry(attempt));
-      attempt = algorithm.createNextAttempt(attempt);
-      clock.incrementNanoTime(Duration.ofMillis(60L).toNanos());
-    }
-
-    assertFalse(algorithm.shouldRetry(attempt));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/FailingCallable.java b/gax/src/test/java/com/google/api/gax/retrying/FailingCallable.java
deleted file mode 100644
index 9b7524ec6..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/FailingCallable.java
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.api.gax.tracing.ApiTracer;
-import java.util.concurrent.Callable;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.atomic.AtomicInteger;
-import org.threeten.bp.Duration;
-
-class FailingCallable implements Callable<String> {
-  static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setMaxAttempts(6)
-          .setInitialRetryDelay(Duration.ofMillis(8L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(8L))
-          .setInitialRpcTimeout(Duration.ofMillis(8L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(8L))
-          .setTotalTimeout(Duration.ofMillis(400L))
-          .build();
-  static final RetrySettings FAILING_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setMaxAttempts(2)
-          .setInitialRetryDelay(Duration.ofNanos(1L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofNanos(1L))
-          .setInitialRpcTimeout(Duration.ofNanos(1L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofNanos(1L))
-          .setTotalTimeout(Duration.ofNanos(1L))
-          .build();
-
-  private AtomicInteger attemptsCount = new AtomicInteger(0);
-  private final ApiTracer tracer;
-  private final int expectedFailuresCount;
-  private final String request;
-  private final String result;
-  private final CountDownLatch firstAttemptFinished = new CountDownLatch(1);
-
-  FailingCallable(int expectedFailuresCount, String request, String result, ApiTracer tracer) {
-    this.request = request;
-    this.tracer = tracer;
-    this.expectedFailuresCount = expectedFailuresCount;
-    this.result = result;
-  }
-
-  CountDownLatch getFirstAttemptFinishedLatch() {
-    return firstAttemptFinished;
-  }
-
-  @Override
-  public String call() throws Exception {
-    try {
-      int attemptNumber = attemptsCount.getAndIncrement();
-
-      tracer.attemptStarted(request, attemptNumber);
-
-      if (attemptNumber < expectedFailuresCount) {
-        throw new CustomException();
-      }
-
-      return result;
-    } finally {
-      firstAttemptFinished.countDown();
-    }
-  }
-
-  static class CustomException extends RuntimeException {
-
-    private static final long serialVersionUID = -1543459008653697004L;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/NoopRetryingContextTest.java b/gax/src/test/java/com/google/api/gax/retrying/NoopRetryingContextTest.java
deleted file mode 100644
index 23a00470d..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/NoopRetryingContextTest.java
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertSame;
-
-import com.google.api.gax.tracing.BaseApiTracer;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class NoopRetryingContextTest {
-
-  @Test
-  public void testGetTracer() {
-    RetryingContext context = NoopRetryingContext.create();
-    assertSame(BaseApiTracer.getInstance(), context.getTracer());
-  }
-
-  @Test
-  public void testGetRetrySettings() {
-    RetryingContext context = NoopRetryingContext.create();
-    assertNull(context.getRetrySettings());
-  }
-
-  @Test
-  public void testGetRetryableCodes() {
-    RetryingContext context = NoopRetryingContext.create();
-    assertNull(context.getRetryableCodes());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/RetryAlgorithmTest.java b/gax/src/test/java/com/google/api/gax/retrying/RetryAlgorithmTest.java
deleted file mode 100644
index a08cdee7f..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/RetryAlgorithmTest.java
+++ /dev/null
@@ -1,205 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static org.junit.Assert.assertFalse;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@SuppressWarnings({"unchecked", "deprecation"})
-@RunWith(JUnit4.class)
-public class RetryAlgorithmTest {
-
-  @Test
-  public void testCreateFirstAttempt() {
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Void> algorithm =
-        new RetryAlgorithm<>(mock(ResultRetryAlgorithm.class), timedAlgorithm);
-
-    algorithm.createFirstAttempt();
-    verify(timedAlgorithm).createFirstAttempt();
-  }
-
-  @Test
-  public void testCreateFirstAttemptWithUnusedContext() {
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Void> algorithm =
-        new RetryAlgorithm<>(mock(ResultRetryAlgorithm.class), timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    algorithm.createFirstAttempt(context);
-    verify(timedAlgorithm).createFirstAttempt();
-  }
-
-  @Test
-  public void testCreateFirstAttemptWithContext() {
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Void> algorithm =
-        new RetryAlgorithm<>(mock(ResultRetryAlgorithmWithContext.class), timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    algorithm.createFirstAttempt(context);
-    verify(timedAlgorithm).createFirstAttempt(context);
-  }
-
-  @Test
-  public void testCreateFirstAttemptWithNullContext() {
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Void> algorithm =
-        new RetryAlgorithm<>(mock(ResultRetryAlgorithmWithContext.class), timedAlgorithm);
-
-    algorithm.createFirstAttempt(null);
-    verify(timedAlgorithm).createFirstAttempt();
-  }
-
-  @Test
-  public void testNextAttempt() {
-    ResultRetryAlgorithm<Object> resultAlgorithm = mock(ResultRetryAlgorithm.class);
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-
-    algorithm.createNextAttempt(previousThrowable, previousResult, previousSettings);
-    verify(resultAlgorithm).shouldRetry(previousThrowable, previousResult);
-  }
-
-  @Test
-  public void testNextAttemptWithContext() {
-    ResultRetryAlgorithmWithContext<Object> resultAlgorithm =
-        mock(ResultRetryAlgorithmWithContext.class);
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-
-    algorithm.createNextAttempt(context, previousThrowable, previousResult, previousSettings);
-    verify(resultAlgorithm).shouldRetry(context, previousThrowable, previousResult);
-  }
-
-  @Test
-  public void testShouldRetry() {
-    ResultRetryAlgorithm<Object> resultAlgorithm = mock(ResultRetryAlgorithm.class);
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-
-    algorithm.shouldRetry(previousThrowable, previousResult, previousSettings);
-    verify(resultAlgorithm).shouldRetry(previousThrowable, previousResult);
-  }
-
-  @Test
-  public void testShouldRetry_usesTimedAlgorithm() {
-    ResultRetryAlgorithm<Object> resultAlgorithm = mock(ResultRetryAlgorithm.class);
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-    when(resultAlgorithm.shouldRetry(previousThrowable, previousResult)).thenReturn(true);
-
-    algorithm.shouldRetry(previousThrowable, previousResult, previousSettings);
-    verify(timedAlgorithm).shouldRetry(previousSettings);
-  }
-
-  @Test
-  public void testShouldRetryWithContext() {
-    ResultRetryAlgorithmWithContext<Object> resultAlgorithm =
-        mock(ResultRetryAlgorithmWithContext.class);
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-
-    algorithm.shouldRetry(context, previousThrowable, previousResult, previousSettings);
-    verify(resultAlgorithm).shouldRetry(context, previousThrowable, previousResult);
-  }
-
-  @Test
-  public void testShouldRetryWithContext_usesTimedAlgorithm() {
-    ResultRetryAlgorithmWithContext<Object> resultAlgorithm =
-        mock(ResultRetryAlgorithmWithContext.class);
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    TimedAttemptSettings previousSettings = mock(TimedAttemptSettings.class);
-    when(resultAlgorithm.shouldRetry(context, previousThrowable, previousResult)).thenReturn(true);
-
-    algorithm.shouldRetry(context, previousThrowable, previousResult, previousSettings);
-    verify(timedAlgorithm).shouldRetry(context, previousSettings);
-  }
-
-  @Test
-  public void testShouldRetry_noPreviousSettings() {
-    ResultRetryAlgorithm<Object> resultAlgorithm = mock(ResultRetryAlgorithm.class);
-    TimedRetryAlgorithm timedAlgorithm = mock(TimedRetryAlgorithm.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-    when(resultAlgorithm.shouldRetry(previousThrowable, previousResult)).thenReturn(true);
-
-    assertFalse(algorithm.shouldRetry(previousThrowable, previousResult, null));
-  }
-
-  @Test
-  public void testShouldRetryWithContext_noPreviousSettings() {
-    ResultRetryAlgorithmWithContext<Object> resultAlgorithm =
-        mock(ResultRetryAlgorithmWithContext.class);
-    TimedRetryAlgorithmWithContext timedAlgorithm = mock(TimedRetryAlgorithmWithContext.class);
-    RetryAlgorithm<Object> algorithm = new RetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    RetryingContext context = mock(RetryingContext.class);
-    Throwable previousThrowable = new Throwable();
-    Object previousResult = new Object();
-
-    assertFalse(algorithm.shouldRetry(context, previousThrowable, previousResult, null));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/RetrySettingsTest.java b/gax/src/test/java/com/google/api/gax/retrying/RetrySettingsTest.java
deleted file mode 100644
index 8bcdea4cc..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/RetrySettingsTest.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import com.google.common.truth.Truth;
-import org.junit.Test;
-import org.threeten.bp.Duration;
-
-public class RetrySettingsTest {
-
-  @Test
-  public void retrySettingsSetLogicalTimeout() {
-    Duration timeout = Duration.ofMillis(60000);
-    RetrySettings retrySettings = RetrySettings.newBuilder().setLogicalTimeout(timeout).build();
-
-    Truth.assertThat(retrySettings.getRpcTimeoutMultiplier()).isEqualTo(1);
-    Truth.assertThat(retrySettings.getInitialRpcTimeout()).isEqualTo(timeout);
-    Truth.assertThat(retrySettings.getMaxRpcTimeout()).isEqualTo(timeout);
-    Truth.assertThat(retrySettings.getTotalTimeout()).isEqualTo(timeout);
-  }
-
-  @Test
-  public void retrySettingsMerge() {
-    RetrySettings.Builder builder =
-        RetrySettings.newBuilder()
-            .setTotalTimeout(Duration.ofMillis(45000))
-            .setInitialRpcTimeout(Duration.ofMillis(2000))
-            .setRpcTimeoutMultiplier(1.5)
-            .setMaxRpcTimeout(Duration.ofMillis(30000))
-            .setInitialRetryDelay(Duration.ofMillis(100))
-            .setRetryDelayMultiplier(1.2)
-            .setMaxRetryDelay(Duration.ofMillis(1000));
-    RetrySettings.Builder mergedBuilder = RetrySettings.newBuilder();
-    mergedBuilder.merge(builder);
-
-    RetrySettings settingsA = builder.build();
-    RetrySettings settingsB = mergedBuilder.build();
-
-    Truth.assertThat(settingsA.getTotalTimeout()).isEqualTo(settingsB.getTotalTimeout());
-    Truth.assertThat(settingsA.getInitialRetryDelay()).isEqualTo(settingsB.getInitialRetryDelay());
-    Truth.assertThat(settingsA.getRpcTimeoutMultiplier())
-        .isWithin(0)
-        .of(settingsB.getRpcTimeoutMultiplier());
-    Truth.assertThat(settingsA.getMaxRpcTimeout()).isEqualTo(settingsB.getMaxRpcTimeout());
-    Truth.assertThat(settingsA.getInitialRetryDelay()).isEqualTo(settingsB.getInitialRetryDelay());
-    Truth.assertThat(settingsA.getRetryDelayMultiplier())
-        .isWithin(0)
-        .of(settingsB.getRetryDelayMultiplier());
-    Truth.assertThat(settingsA.getMaxRetryDelay()).isEqualTo(settingsB.getMaxRetryDelay());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/retrying/ScheduledRetryingExecutorTest.java b/gax/src/test/java/com/google/api/gax/retrying/ScheduledRetryingExecutorTest.java
deleted file mode 100644
index 76793ec98..000000000
--- a/gax/src/test/java/com/google/api/gax/retrying/ScheduledRetryingExecutorTest.java
+++ /dev/null
@@ -1,337 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.retrying;
-
-import static com.google.api.gax.retrying.FailingCallable.FAST_RETRY_SETTINGS;
-import static junit.framework.TestCase.assertFalse;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.retrying.FailingCallable.CustomException;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.RejectedExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import org.junit.After;
-import org.junit.Test;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-// @RunWith(MockitoJUnitRunner.class)
-public class ScheduledRetryingExecutorTest extends AbstractRetryingExecutorTest {
-  private ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
-
-  // Number of test runs, essential for multithreaded tests.
-  private static final int EXECUTIONS_COUNT = 5;
-
-  @Override
-  protected RetryingExecutorWithContext<String> getExecutor(RetryAlgorithm<String> retryAlgorithm) {
-    return getRetryingExecutor(retryAlgorithm, scheduler);
-  }
-
-  @Override
-  protected RetryAlgorithm<String> getAlgorithm(
-      RetrySettings retrySettings, int apocalypseCountDown, RuntimeException apocalypseException) {
-    return new RetryAlgorithm<>(
-        new TestResultRetryAlgorithm<String>(apocalypseCountDown, apocalypseException),
-        new ExponentialRetryAlgorithm(retrySettings, NanoClock.getDefaultClock()));
-  }
-
-  private RetryingExecutorWithContext<String> getRetryingExecutor(
-      RetryAlgorithm<String> retryAlgorithm, ScheduledExecutorService scheduler) {
-    return new ScheduledRetryingExecutor<>(retryAlgorithm, scheduler);
-  }
-
-  @After
-  public void after() {
-    scheduler.shutdownNow();
-  }
-
-  @Test
-  public void testSuccessWithFailuresPeekAttempt() throws Exception {
-    for (int executionsCount = 0; executionsCount < EXECUTIONS_COUNT; executionsCount++) {
-      final int maxRetries = 100;
-
-      ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-      FailingCallable callable = new FailingCallable(15, "request", "SUCCESS", tracer);
-
-      RetrySettings retrySettings =
-          FAST_RETRY_SETTINGS
-              .toBuilder()
-              .setTotalTimeout(Duration.ofMillis(1000L))
-              .setMaxAttempts(maxRetries)
-              .build();
-
-      RetryingExecutorWithContext<String> executor =
-          getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-      RetryingFuture<String> future =
-          executor.createFuture(callable, FakeCallContext.createDefault().withTracer(tracer));
-
-      assertNull(future.peekAttemptResult());
-      assertSame(future.peekAttemptResult(), future.peekAttemptResult());
-      assertFalse(future.getAttemptResult().isDone());
-      assertFalse(future.getAttemptResult().isCancelled());
-
-      future.setAttemptFuture(executor.submit(future));
-
-      int failedAttempts = 0;
-      while (!future.isDone()) {
-        ApiFuture<String> attemptResult = future.peekAttemptResult();
-        if (attemptResult != null) {
-          assertTrue(attemptResult.isDone());
-          assertFalse(attemptResult.isCancelled());
-          try {
-            attemptResult.get();
-          } catch (ExecutionException e) {
-            if (e.getCause() instanceof CustomException) {
-              failedAttempts++;
-            }
-          }
-        }
-        Thread.sleep(0L, 100);
-      }
-
-      assertFutureSuccess(future);
-      assertEquals(15, future.getAttemptSettings().getAttemptCount());
-      assertTrue(failedAttempts > 0);
-      localExecutor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testSuccessWithFailuresGetAttempt() throws Exception {
-    for (int executionsCount = 0; executionsCount < EXECUTIONS_COUNT; executionsCount++) {
-      final int maxRetries = 100;
-
-      ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-      FailingCallable callable = new FailingCallable(15, "request", "SUCCESS", tracer);
-      RetrySettings retrySettings =
-          FAST_RETRY_SETTINGS
-              .toBuilder()
-              .setTotalTimeout(Duration.ofMillis(1000L))
-              .setMaxAttempts(maxRetries)
-              .build();
-
-      RetryingExecutorWithContext<String> executor =
-          getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-      RetryingFuture<String> future =
-          executor.createFuture(callable, FakeCallContext.createDefault().withTracer(tracer));
-
-      assertNull(future.peekAttemptResult());
-      assertSame(future.getAttemptResult(), future.getAttemptResult());
-      assertFalse(future.getAttemptResult().isDone());
-      assertFalse(future.getAttemptResult().isCancelled());
-
-      future.setAttemptFuture(executor.submit(future));
-
-      CustomException exception;
-      int checks = 0;
-      do {
-        exception = null;
-        checks++;
-        Future<String> attemptResult = future.getAttemptResult();
-        try {
-          // testing that the gotten attempt result is non-cancelable
-          assertFalse(attemptResult.cancel(false));
-          assertFalse(attemptResult.cancel(true));
-          attemptResult.get();
-          assertNotNull(future.peekAttemptResult());
-        } catch (ExecutionException e) {
-          exception = (CustomException) e.getCause();
-        }
-        assertTrue(attemptResult.isDone());
-        assertFalse(attemptResult.isCancelled());
-      } while (exception != null && checks < maxRetries + 1);
-
-      assertTrue(future.isDone());
-      assertFutureSuccess(future);
-      assertEquals(15, future.getAttemptSettings().getAttemptCount());
-      assertTrue("checks is equal to " + checks, checks > 1 && checks <= maxRetries);
-      localExecutor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testCancelGetAttempt() throws Exception {
-    for (int executionsCount = 0; executionsCount < EXECUTIONS_COUNT; executionsCount++) {
-      ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-      final int maxRetries = 100;
-
-      FailingCallable callable = new FailingCallable(maxRetries - 1, "request", "SUCCESS", tracer);
-      RetrySettings retrySettings =
-          FAST_RETRY_SETTINGS
-              .toBuilder()
-              .setTotalTimeout(Duration.ofMillis(1000L))
-              .setMaxAttempts(maxRetries)
-              .build();
-
-      RetryingExecutorWithContext<String> executor =
-          getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-      RetryingFuture<String> future = executor.createFuture(callable, retryingContext);
-
-      assertNull(future.peekAttemptResult());
-      assertSame(future.getAttemptResult(), future.getAttemptResult());
-      assertFalse(future.getAttemptResult().isDone());
-      assertFalse(future.getAttemptResult().isCancelled());
-
-      future.setAttemptFuture(executor.submit(future));
-
-      CustomException exception;
-      CancellationException cancellationException = null;
-      int checks = 0;
-      int failedCancelations = 0;
-      do {
-        exception = null;
-        checks++;
-        Future<String> attemptResult = future.getAttemptResult();
-        try {
-          attemptResult.get();
-          assertNotNull(future.peekAttemptResult());
-        } catch (CancellationException e) {
-          cancellationException = e;
-        } catch (ExecutionException e) {
-          exception = (CustomException) e.getCause();
-        }
-        assertTrue(attemptResult.isDone());
-        if (!future.cancel(true)) {
-          failedCancelations++;
-        }
-      } while (exception != null && checks < maxRetries);
-
-      assertTrue(future.isDone());
-      assertNotNull(cancellationException);
-      // future.cancel(true) may return false sometimes, which is ok. Also, the every cancellation
-      // of
-      // an already cancelled future should return false (this is what -1 means here)
-      assertEquals(2, checks - (failedCancelations - 1));
-      assertTrue(future.getAttemptSettings().getAttemptCount() > 0);
-      assertFutureCancel(future);
-      localExecutor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testCancelOuterFutureAfterStart() throws Exception {
-    for (int executionsCount = 0; executionsCount < EXECUTIONS_COUNT; executionsCount++) {
-      ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-      FailingCallable callable = new FailingCallable(4, "requset", "SUCCESS", tracer);
-      RetrySettings retrySettings =
-          FAST_RETRY_SETTINGS
-              .toBuilder()
-              .setInitialRetryDelay(Duration.ofMillis(1_000L))
-              .setMaxRetryDelay(Duration.ofMillis(1_000L))
-              .setTotalTimeout(Duration.ofMillis(10_0000L))
-              .build();
-      RetryingExecutorWithContext<String> executor =
-          getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-      RetryingFuture<String> future =
-          executor.createFuture(callable, FakeCallContext.createDefault().withTracer(tracer));
-      future.setAttemptFuture(executor.submit(future));
-
-      Thread.sleep(30L);
-
-      boolean res = future.cancel(false);
-      assertTrue(res);
-      assertFutureCancel(future);
-      assertTrue(future.getAttemptSettings().getAttemptCount() < 4);
-      localExecutor.shutdownNow();
-    }
-  }
-
-  @Test
-  public void testCancelIsTraced() throws Exception {
-    ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-    FailingCallable callable = new FailingCallable(4, "request", "SUCCESS", tracer);
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(1_000L))
-            .setMaxRetryDelay(Duration.ofMillis(1_000L))
-            .setTotalTimeout(Duration.ofMillis(10_0000L))
-            .build();
-    RetryingExecutorWithContext<String> executor =
-        getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-    RetryingFuture<String> future =
-        executor.createFuture(callable, FakeCallContext.createDefault().withTracer(tracer));
-    future.setAttemptFuture(executor.submit(future));
-
-    Thread.sleep(30L);
-
-    boolean res = future.cancel(false);
-    assertTrue(res);
-    assertFutureCancel(future);
-
-    Mockito.verify(tracer).attemptCancelled();
-    localExecutor.shutdownNow();
-  }
-
-  @Test
-  public void testCancelProxiedFutureAfterStart() throws Exception {
-    // this is a heavy test, which takes a lot of time, so only few executions.
-    for (int executionsCount = 0; executionsCount < 2; executionsCount++) {
-      ScheduledExecutorService localExecutor = Executors.newSingleThreadScheduledExecutor();
-      FailingCallable callable = new FailingCallable(5, "request", "SUCCESS", tracer);
-      RetrySettings retrySettings =
-          FAST_RETRY_SETTINGS
-              .toBuilder()
-              .setInitialRetryDelay(Duration.ofMillis(1_000L))
-              .setMaxRetryDelay(Duration.ofMillis(1_000L))
-              .setTotalTimeout(Duration.ofMillis(10_0000L))
-              .build();
-      RetryingExecutorWithContext<String> executor =
-          getRetryingExecutor(getAlgorithm(retrySettings, 0, null), localExecutor);
-      RetryingFuture<String> future =
-          executor.createFuture(callable, FakeCallContext.createDefault().withTracer(tracer));
-      future.setAttemptFuture(executor.submit(future));
-
-      Thread.sleep(50L);
-
-      // Note that shutdownNow() will not cancel internal FutureTasks automatically, which
-      // may potentially cause another thread handing on RetryingFuture#get() call forever.
-      // Canceling the tasks returned by shutdownNow() also does not help, because of missing
-      // feature
-      // in guava's ListenableScheduledFuture, which does not cancel itself, when its delegate is
-      // canceled.
-      // So only the graceful shutdown() is supported properly.
-      localExecutor.shutdown();
-
-      assertFutureFail(future, RejectedExecutionException.class);
-      localExecutor.shutdownNow();
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/AccumulatingStreamObserver.java b/gax/src/test/java/com/google/api/gax/rpc/AccumulatingStreamObserver.java
deleted file mode 100644
index 65c31f92b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/AccumulatingStreamObserver.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import java.util.ArrayList;
-import java.util.List;
-
-/** Package-private for internal use. */
-class AccumulatingStreamObserver extends StateCheckingResponseObserver<Integer> {
-  private List<Integer> values = new ArrayList<>();
-  private StreamController controller;
-  private Throwable error;
-  private boolean completed = false;
-
-  @Override
-  protected void onStartImpl(StreamController controller) {
-    this.controller = controller;
-  }
-
-  @Override
-  protected void onResponseImpl(Integer value) {
-    values.add(value);
-  }
-
-  @Override
-  protected void onErrorImpl(Throwable t) {
-    error = t;
-  }
-
-  @Override
-  protected void onCompleteImpl() {
-    completed = true;
-  }
-
-  public List<Integer> getValues() {
-    if (!completed) {
-      throw new IllegalStateException("Stream not completed.");
-    }
-    if (error != null) {
-      throw ApiExceptionFactory.createException(error, FakeStatusCode.of(Code.UNKNOWN), false);
-    }
-    return values;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ApiClientHeaderProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/ApiClientHeaderProviderTest.java
deleted file mode 100644
index f60c3c076..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ApiClientHeaderProviderTest.java
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiClientHeaderProviderTest {
-
-  private static final String X_GOOG_API_CLIENT = "x-goog-api-client";
-  private static final String CLOUD_RESOURCE_PREFIX = "google-cloud-resource-prefix";
-
-  @Test
-  public void testServiceHeaderDefault() {
-    ApiClientHeaderProvider provider = ApiClientHeaderProvider.newBuilder().build();
-    assertThat(provider.getHeaders().size()).isEqualTo(1);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT)).matches("^gl-java/.* gax/.*$");
-  }
-
-  @Test
-  public void testServiceHeaderManual() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder().setClientLibToken("gccl", "1.2.3").build();
-    assertThat(provider.getHeaders().size()).isEqualTo(1);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gccl/1\\.2\\.3 gax/.*$");
-  }
-
-  @Test
-  public void testServiceHeaderManualGapic() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setTransportToken("grpc", "1.2.3")
-            .setClientLibToken("gccl", "4.5.6")
-            .setGeneratedLibToken("gapic", "7.8.9")
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(1);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gccl/4\\.5\\.6 gapic/7\\.8\\.9 gax/.* grpc/1\\.2\\.3$");
-  }
-
-  @Test
-  public void testServiceHeaderManualGrpc() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setTransportToken("grpc", "1.2.3")
-            .setClientLibToken("gccl", "4.5.6")
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(1);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gccl/4\\.5\\.6 gax/.* grpc/1\\.2\\.3$");
-  }
-
-  @Test
-  public void testServiceHeaderGapic() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setTransportToken("grpc", "1.2.3")
-            .setGeneratedLibToken("gapic", "4.5.6")
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(1);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gapic/4\\.5\\.6 gax/.* grpc/1\\.2\\.3$");
-  }
-
-  @Test
-  public void testCloudResourcePrefixHeader() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setTransportToken("grpc", "1.2.3")
-            .setGeneratedLibToken("gapic", "4.5.6")
-            .setResourceToken("test-prefix")
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(2);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gapic/4\\.5\\.6 gax/.* grpc/1\\.2\\.3$");
-    assertThat(provider.getHeaders().get(CLOUD_RESOURCE_PREFIX)).isEqualTo("test-prefix");
-  }
-
-  @Test
-  public void testCustomHeaderKeys() {
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setTransportToken("grpc", "1.2.3")
-            .setGeneratedLibToken("gapic", "4.5.6")
-            .setResourceToken("test-prefix")
-            .setApiClientHeaderKey("custom-header1")
-            .setResourceHeaderKey("custom-header2")
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(2);
-    assertThat(provider.getHeaders().get("custom-header1"))
-        .matches("^gl-java/.* gapic/4\\.5\\.6 gax/.* grpc/1\\.2\\.3$");
-    assertThat(provider.getHeaders().get("custom-header2")).isEqualTo("test-prefix");
-  }
-
-  @Test
-  public void testQuotaProjectHeader() {
-    String quotaProjectHeaderValue = "quota-project-id-value";
-    ApiClientHeaderProvider provider =
-        ApiClientHeaderProvider.newBuilder()
-            .setClientLibToken("gccl", "1.2.3")
-            .setQuotaProjectIdToken(quotaProjectHeaderValue)
-            .build();
-    assertThat(provider.getHeaders().size()).isEqualTo(2);
-    assertThat(provider.getHeaders().get(X_GOOG_API_CLIENT))
-        .matches("^gl-java/.* gccl/1\\.2\\.3 gax/.*$");
-    assertThat(provider.getHeaders().get(ApiClientHeaderProvider.QUOTA_PROJECT_ID_HEADER_KEY))
-        .matches(quotaProjectHeaderValue);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionFactoryTest.java b/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionFactoryTest.java
deleted file mode 100644
index 52e224421..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionFactoryTest.java
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.truth.Truth;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiExceptionFactoryTest {
-
-  @Test
-  public void cancelled() {
-    Truth.assertThat(createException(Code.CANCELLED)).isInstanceOf(CancelledException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.CANCELLED))
-        .isInstanceOf(CancelledException.class);
-  }
-
-  @Test
-  public void notFound() {
-    Truth.assertThat(createException(Code.NOT_FOUND)).isInstanceOf(NotFoundException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.NOT_FOUND))
-        .isInstanceOf(NotFoundException.class);
-  }
-
-  @Test
-  public void unknown() {
-    Truth.assertThat(createException(Code.UNKNOWN)).isInstanceOf(UnknownException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.UNKNOWN)).isInstanceOf(UnknownException.class);
-  }
-
-  @Test
-  public void invalidArgument() {
-    Truth.assertThat(createException(Code.INVALID_ARGUMENT))
-        .isInstanceOf(InvalidArgumentException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.INVALID_ARGUMENT))
-        .isInstanceOf(InvalidArgumentException.class);
-  }
-
-  @Test
-  public void deadlineExceeded() {
-    Truth.assertThat(createException(Code.DEADLINE_EXCEEDED))
-        .isInstanceOf(DeadlineExceededException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.DEADLINE_EXCEEDED))
-        .isInstanceOf(DeadlineExceededException.class);
-  }
-
-  @Test
-  public void alreadyExists() {
-    Truth.assertThat(createException(Code.ALREADY_EXISTS))
-        .isInstanceOf(AlreadyExistsException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.ALREADY_EXISTS))
-        .isInstanceOf(AlreadyExistsException.class);
-  }
-
-  @Test
-  public void permissionDenied() {
-    Truth.assertThat(createException(Code.PERMISSION_DENIED))
-        .isInstanceOf(PermissionDeniedException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.PERMISSION_DENIED))
-        .isInstanceOf(PermissionDeniedException.class);
-  }
-
-  @Test
-  public void resourceExhausted() {
-    Truth.assertThat(createException(Code.RESOURCE_EXHAUSTED))
-        .isInstanceOf(ResourceExhaustedException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.RESOURCE_EXHAUSTED))
-        .isInstanceOf(ResourceExhaustedException.class);
-  }
-
-  @Test
-  public void failedPrecondition() {
-    Truth.assertThat(createException(Code.FAILED_PRECONDITION))
-        .isInstanceOf(FailedPreconditionException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.FAILED_PRECONDITION))
-        .isInstanceOf(FailedPreconditionException.class);
-  }
-
-  @Test
-  public void aborted() {
-    Truth.assertThat(createException(Code.ABORTED)).isInstanceOf(AbortedException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.ABORTED)).isInstanceOf(AbortedException.class);
-  }
-
-  @Test
-  public void outOfRange() {
-    Truth.assertThat(createException(Code.OUT_OF_RANGE)).isInstanceOf(OutOfRangeException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.OUT_OF_RANGE))
-        .isInstanceOf(OutOfRangeException.class);
-  }
-
-  @Test
-  public void internal() {
-    Truth.assertThat(createException(Code.INTERNAL)).isInstanceOf(InternalException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.INTERNAL))
-        .isInstanceOf(InternalException.class);
-  }
-
-  @Test
-  public void unavailable() {
-    Truth.assertThat(createException(Code.UNAVAILABLE)).isInstanceOf(UnavailableException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.UNAVAILABLE))
-        .isInstanceOf(UnavailableException.class);
-  }
-
-  @Test
-  public void dataLoss() {
-    Truth.assertThat(createException(Code.DATA_LOSS)).isInstanceOf(DataLossException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.DATA_LOSS))
-        .isInstanceOf(DataLossException.class);
-  }
-
-  @Test
-  public void unauthenticated() {
-    Truth.assertThat(createException(Code.UNAUTHENTICATED))
-        .isInstanceOf(UnauthenticatedException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.UNAUTHENTICATED))
-        .isInstanceOf(UnauthenticatedException.class);
-  }
-
-  @Test
-  public void unimplemented() {
-    Truth.assertThat(createException(Code.UNIMPLEMENTED))
-        .isInstanceOf(UnimplementedException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.UNIMPLEMENTED))
-        .isInstanceOf(UnimplementedException.class);
-  }
-
-  @Test
-  public void unknown_default() {
-    Truth.assertThat(createException(Code.OK)).isInstanceOf(UnknownException.class);
-    Truth.assertThat(createExceptionWithMessage(Code.OK)).isInstanceOf(UnknownException.class);
-  }
-
-  private ApiException createException(StatusCode.Code statusCode) {
-    return ApiExceptionFactory.createException(
-        new RuntimeException(), FakeStatusCode.of(statusCode), false);
-  }
-
-  private ApiException createExceptionWithMessage(StatusCode.Code statusCode) {
-    return ApiExceptionFactory.createException(
-        "message", new RuntimeException(), FakeStatusCode.of(statusCode), false);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionTest.java b/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionTest.java
deleted file mode 100644
index 85bf2d9ec..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionTest.java
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Any;
-import com.google.rpc.ErrorInfo;
-import java.util.Collections;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiExceptionTest {
-
-  private static final ErrorDetails ERROR_DETAILS_WITH_NO_ERROR_INFO =
-      ErrorDetails.builder().setRawErrorMessages(Collections.emptyList()).build();
-  private static final String DOMAIN = "googleapis.com";
-  private static final String REASON = "SERVICE_DISABLED";
-  private static final String METADATA_KEY = "service";
-  private static final String METADATA_VALUE = "language.googleapis.com";
-  private static final ErrorDetails ERROR_DETAILS_WITH_ERROR_INFO =
-      ErrorDetails.builder()
-          .setRawErrorMessages(
-              ImmutableList.of(
-                  Any.pack(
-                      ErrorInfo.newBuilder()
-                          .setDomain(DOMAIN)
-                          .setReason(REASON)
-                          .putMetadata(METADATA_KEY, METADATA_VALUE)
-                          .build())))
-          .build();
-  private static final FakeStatusCode STATUS_CODE = FakeStatusCode.of(Code.UNAVAILABLE);
-
-  private ApiException apiException;
-
-  @Test
-  public void getReason_shouldReturnNullIfErrorDetailsIsNull() {
-    apiException = new ApiException(null, STATUS_CODE, false, null);
-
-    Truth.assertThat(apiException.getReason()).isNull();
-  }
-
-  @Test
-  public void getReason_shouldReturnNullIfErrorInfoIsNull() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_NO_ERROR_INFO);
-
-    Truth.assertThat(apiException.getReason()).isNull();
-  }
-
-  @Test
-  public void getReason_shouldReturnReasonIfAvailable() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_ERROR_INFO);
-
-    Truth.assertThat(apiException.getReason()).isEqualTo(REASON);
-  }
-
-  @Test
-  public void getDomain_shouldReturnNullIfErrorInfoIsNull() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_NO_ERROR_INFO);
-
-    Truth.assertThat(apiException.getDomain()).isNull();
-  }
-
-  @Test
-  public void getDomain_shouldReturnDomainIfAvailable() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_ERROR_INFO);
-
-    Truth.assertThat(apiException.getDomain()).isEqualTo(DOMAIN);
-  }
-
-  @Test
-  public void getMetadata_shouldReturnNullIfErrorInfoIsNull() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_NO_ERROR_INFO);
-
-    Truth.assertThat(apiException.getMetadata()).isNull();
-  }
-
-  @Test
-  public void getMetadata_shouldReturnMetadataIfAvailable() {
-    apiException = new ApiException(null, STATUS_CODE, false, ERROR_DETAILS_WITH_ERROR_INFO);
-
-    Truth.assertThat(apiException.getMetadata()).containsExactly(METADATA_KEY, METADATA_VALUE);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionsTest.java b/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionsTest.java
deleted file mode 100644
index 411f21b2b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ApiExceptionsTest.java
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.ApiFutures;
-import com.google.api.core.ListenableFutureToApiFuture;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.ListeningExecutorService;
-import com.google.common.util.concurrent.MoreExecutors;
-import com.google.common.util.concurrent.UncheckedExecutionException;
-import java.io.IOException;
-import java.util.concurrent.Executors;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiExceptionsTest {
-
-  @Test
-  public void noException() {
-    Integer result = ApiExceptions.callAndTranslateApiException(ApiFutures.immediateFuture(2));
-    assertThat(result).isEqualTo(2);
-  }
-
-  @Test
-  public void throwsApiException() {
-    Exception throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), false);
-    try {
-      ApiExceptions.callAndTranslateApiException(ApiFutures.immediateFailedFuture(throwable));
-      Assert.fail("ApiExceptions should have thrown an exception");
-    } catch (ApiException expected) {
-      assertThat(expected).isSameInstanceAs(throwable);
-    }
-  }
-
-  @Test
-  public void throwsIOException() {
-    try {
-      ApiExceptions.callAndTranslateApiException(
-          ApiFutures.immediateFailedFuture(new IOException()));
-      Assert.fail("ApiExceptions should have thrown an exception");
-    } catch (UncheckedExecutionException expected) {
-      assertThat(expected).hasCauseThat().isInstanceOf(IOException.class);
-    }
-  }
-
-  @Test
-  public void throwsRuntimeException() {
-    try {
-      ApiExceptions.callAndTranslateApiException(
-          ApiFutures.immediateFailedFuture(new IllegalArgumentException()));
-      Assert.fail("ApiExceptions should have thrown an exception");
-    } catch (IllegalArgumentException expected) {
-      assertThat(expected).isInstanceOf(IllegalArgumentException.class);
-    }
-  }
-
-  /**
-   * Make sure that the caller's stacktrace is preserved when the future is unwrapped. The
-   * stacktrace will be preserved as a suppressed RuntimeException.
-   */
-  @Test
-  public void containsCurrentStacktrace() {
-    final String currentMethod = "containsCurrentStacktrace";
-
-    // Throw an error in an executor, which will cause it to lose the current stack frame
-    ListeningExecutorService executor =
-        MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor());
-
-    ListenableFuture<?> futureError =
-        executor.submit(
-            new Runnable() {
-              @Override
-              public void run() {
-                throw new IllegalArgumentException();
-              }
-            });
-    ListenableFutureToApiFuture<?> futureErrorWrapper =
-        new ListenableFutureToApiFuture<>(futureError);
-    executor.shutdown();
-
-    // Unwrap the future
-    Exception actualError = null;
-    try {
-      ApiExceptions.callAndTranslateApiException(futureErrorWrapper);
-    } catch (Exception e) {
-      actualError = e;
-    }
-
-    // Sanity check that the current stack trace is not in the exception
-    assertThat(actualError).isNotNull();
-    assertThat(isMethodInStacktrace(currentMethod, actualError)).isFalse();
-
-    // Verify that it is preserved as a suppressed exception.
-    assertThat(actualError.getSuppressed()[0]).isInstanceOf(AsyncTaskException.class);
-    assertThat(isMethodInStacktrace(currentMethod, actualError.getSuppressed()[0])).isTrue();
-  }
-
-  private static boolean isMethodInStacktrace(String method, Throwable t) {
-    for (StackTraceElement e : t.getStackTrace()) {
-      if (method.equals(e.getMethodName())) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ApiResultRetryAlgorithmTest.java b/gax/src/test/java/com/google/api/gax/rpc/ApiResultRetryAlgorithmTest.java
deleted file mode 100644
index 4e04c1a0b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ApiResultRetryAlgorithmTest.java
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.common.collect.Sets;
-import java.util.Collections;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiResultRetryAlgorithmTest {
-
-  @Test
-  public void testShouldRetryNoContext() {
-    ApiException nonRetryable =
-        new ApiException(null, new FakeStatusCode(Code.INTERNAL), /* retryable = */ false);
-    ApiException retryable =
-        new ApiException(null, new FakeStatusCode(Code.UNAVAILABLE), /* retryable = */ true);
-
-    ApiResultRetryAlgorithm<String> algorithm = new ApiResultRetryAlgorithm<>();
-    assertFalse(algorithm.shouldRetry(nonRetryable, null));
-    assertTrue(algorithm.shouldRetry(retryable, null));
-  }
-
-  @Test
-  public void testShouldRetryWithContextWithoutRetryableCodes() {
-    ApiCallContext context = mock(ApiCallContext.class);
-    // No retryable codes in the call context, means that the retry algorithm should fall back to
-    // its default implementation.
-    when(context.getRetryableCodes()).thenReturn(null);
-
-    ApiException nonRetryable =
-        new ApiException(null, new FakeStatusCode(Code.UNAVAILABLE), /* retryable = */ false);
-    ApiException retryable =
-        new ApiException(null, new FakeStatusCode(Code.UNAVAILABLE), /* retryable = */ true);
-
-    ApiResultRetryAlgorithm<String> algorithm = new ApiResultRetryAlgorithm<>();
-    assertFalse(algorithm.shouldRetry(context, nonRetryable, null));
-    assertTrue(algorithm.shouldRetry(context, retryable, null));
-  }
-
-  @Test
-  public void testShouldRetryWithContextWithRetryableCodes() {
-    ApiCallContext context = mock(ApiCallContext.class);
-    when(context.getRetryableCodes())
-        .thenReturn(
-            Sets.newHashSet(StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE));
-
-    StatusCode unavailable = mock(StatusCode.class);
-    when(unavailable.getCode()).thenReturn(Code.UNAVAILABLE);
-    StatusCode dataLoss = mock(StatusCode.class);
-    when(dataLoss.getCode()).thenReturn(Code.DATA_LOSS);
-
-    // The return value of isRetryable() will be ignored, as UNAVAILABLE has been added as a
-    // retryable code to the call context.
-    ApiException unavailableException =
-        new ApiException(null, new FakeStatusCode(Code.UNAVAILABLE), /* retryable = */ false);
-    ApiException dataLossException =
-        new ApiException(null, new FakeStatusCode(Code.DATA_LOSS), /* retryable = */ true);
-
-    ApiResultRetryAlgorithm<String> algorithm = new ApiResultRetryAlgorithm<>();
-    assertTrue(algorithm.shouldRetry(context, unavailableException, null));
-    assertFalse(algorithm.shouldRetry(context, dataLossException, null));
-  }
-
-  @Test
-  public void testShouldRetryWithContextWithEmptyRetryableCodes() {
-    ApiCallContext context = mock(ApiCallContext.class);
-    // This will effectively make the RPC non-retryable.
-    when(context.getRetryableCodes()).thenReturn(Collections.<Code>emptySet());
-
-    ApiException unavailableException =
-        new ApiException(null, new FakeStatusCode(Code.UNAVAILABLE), /* retryable = */ true);
-
-    ApiResultRetryAlgorithm<String> algorithm = new ApiResultRetryAlgorithm<>();
-    assertFalse(algorithm.shouldRetry(context, unavailableException, null));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/AttemptCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/AttemptCallableTest.java
deleted file mode 100644
index 3b16b568d..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/AttemptCallableTest.java
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.mockito.stubbing.Answer;
-import org.threeten.bp.Duration;
-
-@RunWith(MockitoJUnitRunner.class)
-public class AttemptCallableTest {
-  @Mock UnaryCallable<String, String> mockInnerCallable;
-  ArgumentCaptor<ApiCallContext> capturedCallContext;
-  @Mock RetryingFuture<String> mockExternalFuture;
-  TimedAttemptSettings currentAttemptSettings;
-
-  @Before
-  public void setUp() {
-    capturedCallContext = ArgumentCaptor.forClass(ApiCallContext.class);
-    Mockito.when(mockInnerCallable.futureCall(Mockito.anyString(), capturedCallContext.capture()))
-        .thenReturn(SettableApiFuture.<String>create());
-
-    currentAttemptSettings =
-        TimedAttemptSettings.newBuilder()
-            .setGlobalSettings(RetrySettings.newBuilder().build())
-            .setAttemptCount(0)
-            .setOverallAttemptCount(0)
-            .setFirstAttemptStartTimeNanos(0)
-            .setRetryDelay(Duration.ofSeconds(1))
-            .setRandomizedRetryDelay(Duration.ofSeconds(1))
-            .setRpcTimeout(Duration.ZERO)
-            .build();
-
-    Mockito.when(mockExternalFuture.getAttemptSettings())
-        .thenAnswer(
-            new Answer<TimedAttemptSettings>() {
-              @Override
-              public TimedAttemptSettings answer(InvocationOnMock invocation) throws Throwable {
-                return currentAttemptSettings;
-              }
-            });
-  }
-
-  @Test
-  public void testRpcTimeout() {
-    AttemptCallable<String, String> callable =
-        new AttemptCallable<>(mockInnerCallable, "fake-request", FakeCallContext.createDefault());
-    callable.setExternalFuture(mockExternalFuture);
-
-    // Make sure that the rpc timeout is set
-    Duration timeout = Duration.ofSeconds(10);
-    currentAttemptSettings = currentAttemptSettings.toBuilder().setRpcTimeout(timeout).build();
-
-    callable.call();
-
-    assertThat(capturedCallContext.getValue().getTimeout()).isEqualTo(timeout);
-
-    // Make sure that subsequent attempts can extend the time out
-    Duration longerTimeout = Duration.ofSeconds(20);
-    currentAttemptSettings =
-        currentAttemptSettings.toBuilder().setRpcTimeout(longerTimeout).build();
-    callable.call();
-    assertThat(capturedCallContext.getValue().getTimeout()).isEqualTo(longerTimeout);
-  }
-
-  @Test
-  public void testRpcTimeoutIsNotErased() {
-    Duration callerTimeout = Duration.ofMillis(10);
-    ApiCallContext callerCallContext = FakeCallContext.createDefault().withTimeout(callerTimeout);
-
-    Duration timeout = Duration.ofMillis(5);
-    currentAttemptSettings = currentAttemptSettings.toBuilder().setRpcTimeout(timeout).build();
-
-    AttemptCallable<String, String> callable =
-        new AttemptCallable<>(mockInnerCallable, "fake-request", callerCallContext);
-    callable.setExternalFuture(mockExternalFuture);
-
-    callable.call();
-
-    assertThat(capturedCallContext.getValue().getTimeout()).isEqualTo(callerTimeout);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/AuthCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/AuthCallableTest.java
deleted file mode 100644
index c0f2f269e..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/AuthCallableTest.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeSimpleApi.StashCallable;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.Credentials;
-import com.google.common.truth.Truth;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class AuthCallableTest {
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    clientContext =
-        ClientContext.newBuilder()
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @Test
-  public void testAuth() throws InterruptedException, ExecutionException, CancellationException {
-    StashCallable<Integer, Integer> stash = new StashCallable<>(42);
-    Truth.assertThat(stash.getContext()).isNull();
-
-    UnaryCallSettings<Integer, Integer> callSettings =
-        UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder().build();
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(
-            stash,
-            callSettings,
-            clientContext.toBuilder().setCredentials(Mockito.mock(Credentials.class)).build());
-    Truth.assertThat(callable.futureCall(0).get()).isEqualTo(42);
-    Truth.assertThat(stash.getContext()).isNotNull();
-    FakeCallContext callContext = (FakeCallContext) stash.getContext();
-    Truth.assertThat(callContext.getCredentials()).isNotNull();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchExecutorTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchExecutorTest.java
deleted file mode 100644
index b55ce9ff2..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchExecutorTest.java
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.RequestBuilder;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class BatchExecutorTest {
-
-  BatchingDescriptor<List<Integer>, Integer> integerDescriptor =
-      new BatchingDescriptor<List<Integer>, Integer>() {
-
-        @Override
-        public PartitionKey getBatchPartitionKey(List<Integer> request) {
-          return new PartitionKey(request.get(0) % 2);
-        }
-
-        @Override
-        public RequestBuilder<List<Integer>> getRequestBuilder() {
-          return new RequestBuilder<List<Integer>>() {
-
-            List<Integer> list = new ArrayList<>();
-
-            @Override
-            public void appendRequest(List<Integer> request) {
-              list.addAll(request);
-            }
-
-            @Override
-            public List<Integer> build() {
-              return list;
-            }
-          };
-        }
-
-        @Override
-        public void splitResponse(
-            Integer batchResponse, Collection<? extends BatchedRequestIssuer<Integer>> batch) {}
-
-        @Override
-        public void splitException(
-            Throwable throwable, Collection<? extends BatchedRequestIssuer<Integer>> batch) {}
-
-        @Override
-        public long countElements(List<Integer> request) {
-          return request.size();
-        }
-
-        @Override
-        public long countBytes(List<Integer> request) {
-          return request.size();
-        }
-      };
-
-  @Test
-  public void testValidate() {
-    BatchExecutor<List<Integer>, Integer> executor =
-        new BatchExecutor<List<Integer>, Integer>(integerDescriptor, new PartitionKey(0));
-    List<Integer> request = new ArrayList<Integer>();
-    request.add(2);
-    Batch<List<Integer>, Integer> batchingContextOk =
-        new Batch<>(integerDescriptor, request, null, null);
-    executor.validateBatch(batchingContextOk);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testValidateFailure() {
-    BatchExecutor<List<Integer>, Integer> executor =
-        new BatchExecutor<List<Integer>, Integer>(integerDescriptor, new PartitionKey(0));
-    List<Integer> request = new ArrayList<>();
-    request.add(3);
-    Batch<List<Integer>, Integer> batchingContextOk =
-        new Batch<>(integerDescriptor, request, null, null);
-    executor.validateBatch(batchingContextOk);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchTest.java
deleted file mode 100644
index 44a2401e9..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchTest.java
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.SQUARER_BATCHING_DESC;
-
-import com.google.api.gax.batching.ElementCounter;
-import com.google.api.gax.rpc.Batch.BatchByteCounter;
-import com.google.api.gax.rpc.Batch.BatchElementCounter;
-import com.google.api.gax.rpc.Batch.BatchMergerImpl;
-import com.google.api.gax.rpc.testing.FakeBatchableApi;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.common.truth.Truth;
-import java.util.ArrayList;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class BatchTest {
-
-  @Test
-  public void testConstructor() {
-    LabeledIntList request = new LabeledIntList("lable", 2);
-    Batch<LabeledIntList, List<Integer>> batch = createBatch(request);
-
-    Truth.assertThat(batch.getRequest()).isEqualTo(request);
-    Truth.assertThat(batch.getCallable()).isSameInstanceAs(batch.getCallable());
-    Truth.assertThat(batch.getRequestIssuerList().size()).isEqualTo(1);
-    Truth.assertThat(batch.getByteCount()).isEqualTo(2);
-  }
-
-  @Test
-  public void testMerge() {
-    LabeledIntList request1 = new LabeledIntList("lable", 1);
-    Batch<LabeledIntList, List<Integer>> batch1 = createBatch(request1);
-
-    LabeledIntList request2 = new LabeledIntList("lable", 2);
-    Batch<LabeledIntList, List<Integer>> batch2 = createBatch(request2);
-
-    batch1.merge(batch2);
-
-    Truth.assertThat(batch1.getByteCount()).isEqualTo(3);
-  }
-
-  @Test
-  public void testMergeStartEmpty() {
-    LabeledIntList request1 = new LabeledIntList("lable", new ArrayList<Integer>());
-    Batch<LabeledIntList, List<Integer>> batch1 = createBatch(request1, null);
-    Truth.assertThat(batch1.getCallable()).isNull();
-
-    LabeledIntList request2 = new LabeledIntList("lable", 2);
-    Batch<LabeledIntList, List<Integer>> batch2 = createBatch(request2);
-
-    batch1.merge(batch2);
-
-    Truth.assertThat(batch1.getByteCount()).isEqualTo(2);
-    Truth.assertThat(batch1.getCallable()).isNotNull();
-    Truth.assertThat(batch1.getCallable()).isSameInstanceAs(batch2.getCallable());
-  }
-
-  @Test
-  public void testBatchElementCounter() {
-    ElementCounter<Batch<LabeledIntList, List<Integer>>> counter =
-        new BatchElementCounter<>(SQUARER_BATCHING_DESC);
-    LabeledIntList request = new LabeledIntList("lable", 3);
-    Batch<LabeledIntList, List<Integer>> batch = createBatch(request);
-
-    Truth.assertThat(counter.count(batch)).isEqualTo(1);
-  }
-
-  @Test
-  public void testBatchByteCounter() {
-    ElementCounter<Batch<LabeledIntList, List<Integer>>> counter = new BatchByteCounter<>();
-    LabeledIntList request = new LabeledIntList("lable", 3);
-    Batch<LabeledIntList, List<Integer>> batch = createBatch(request);
-
-    Truth.assertThat(counter.count(batch)).isEqualTo(3);
-  }
-
-  @Test
-  public void testBatchMergerImpl() {
-    LabeledIntList request1 = new LabeledIntList("lable", 1);
-    Batch<LabeledIntList, List<Integer>> batch1 = createBatch(request1);
-
-    LabeledIntList request2 = new LabeledIntList("lable", 2);
-    Batch<LabeledIntList, List<Integer>> batch2 = createBatch(request2);
-
-    BatchMergerImpl<LabeledIntList, List<Integer>> batchMerger = new BatchMergerImpl<>();
-    batchMerger.merge(batch1, batch2);
-
-    Truth.assertThat(batch1.getByteCount()).isEqualTo(3);
-  }
-
-  private Batch<LabeledIntList, List<Integer>> createBatch(LabeledIntList request) {
-    @SuppressWarnings("unchecked")
-    UnaryCallable<FakeBatchableApi.LabeledIntList, List<Integer>> callable =
-        Mockito.mock(UnaryCallable.class);
-    return createBatch(request, callable);
-  }
-
-  private Batch<LabeledIntList, List<Integer>> createBatch(
-      LabeledIntList request,
-      UnaryCallable<FakeBatchableApi.LabeledIntList, List<Integer>> callable) {
-    BatchingDescriptor<LabeledIntList, List<Integer>> batchingDescriptor = SQUARER_BATCHING_DESC;
-    BatchedFuture<List<Integer>> batchedFuture = new BatchedFuture<>();
-
-    return new Batch<>(batchingDescriptor, request, callable, batchedFuture);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchedFutureTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchedFutureTest.java
deleted file mode 100644
index 55ed0c226..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchedFutureTest.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.common.truth.Truth;
-import java.util.concurrent.TimeUnit;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class BatchedFutureTest {
-  @Test
-  public void testSet() throws Exception {
-    BatchedFuture<Integer> future = BatchedFuture.create();
-    Truth.assertThat(future.isDone()).isFalse();
-    future.set(42);
-    Truth.assertThat(future.get()).isEqualTo(42);
-    Truth.assertThat(future.get(1, TimeUnit.HOURS)).isEqualTo(42);
-    Truth.assertThat(future.isDone()).isTrue();
-  }
-
-  @Test
-  public void testTransform() throws Exception {
-    BatchedFuture<Integer> inputFuture = BatchedFuture.<Integer>create();
-    ApiFuture<String> transformedFuture =
-        ApiFutures.transform(
-            inputFuture,
-            new ApiFunction<Integer, String>() {
-              @Override
-              public String apply(Integer input) {
-                return input.toString();
-              }
-            },
-            directExecutor());
-    inputFuture.set(6);
-    Truth.assertThat(transformedFuture.get()).isEqualTo("6");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchedRequestIssuerTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchedRequestIssuerTest.java
deleted file mode 100644
index 293252afc..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchedRequestIssuerTest.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.common.truth.Truth;
-import java.util.concurrent.ExecutionException;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class BatchedRequestIssuerTest {
-
-  @Test
-  public void test() throws Exception {
-    BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-    BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-    issuer.setResponse(1);
-
-    Truth.assertThat(batchedFuture.isDone()).isFalse();
-    issuer.sendResult();
-
-    Truth.assertThat(batchedFuture.isDone()).isTrue();
-    Truth.assertThat(batchedFuture.get()).isEqualTo(1);
-  }
-
-  @Test
-  public void testNullResult() throws Exception {
-    BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-    BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-    issuer.setResponse(null);
-
-    Truth.assertThat(batchedFuture.isDone()).isFalse();
-    issuer.sendResult();
-
-    Truth.assertThat(batchedFuture.isDone()).isTrue();
-    Truth.assertThat(batchedFuture.get()).isNull();
-  }
-
-  @Test
-  public void testException() throws Exception {
-    Exception thrownException = new IllegalArgumentException("bad!");
-
-    BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-    BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-    issuer.setException(thrownException);
-
-    Truth.assertThat(batchedFuture.isDone()).isFalse();
-    issuer.sendResult();
-
-    Truth.assertThat(batchedFuture.isDone()).isTrue();
-    try {
-      batchedFuture.get();
-      Assert.fail("BatchedFuture should have thrown an exception");
-    } catch (ExecutionException e) {
-      Truth.assertThat(e.getCause()).isInstanceOf(IllegalArgumentException.class);
-    }
-  }
-
-  @Test
-  public void testNoResult() {
-    try {
-      BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-      BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-      issuer.sendResult();
-      Assert.fail("BatchedFuture should have thrown an exception");
-    } catch (IllegalStateException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("Neither response nor exception were set in BatchedRequestIssuer");
-    }
-  }
-
-  @Test
-  public void testResponseAndException() {
-    try {
-      Exception thrownException = new IllegalArgumentException("bad!");
-      BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-      BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-      issuer.setResponse(1);
-      issuer.setException(thrownException);
-      Assert.fail("BatchedFuture should have thrown an exception");
-    } catch (IllegalStateException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("Cannot set both exception and response");
-    }
-  }
-
-  @Test
-  public void testExceptionAndResponse() {
-    try {
-      Exception thrownException = new IllegalArgumentException("bad!");
-      BatchedFuture<Integer> batchedFuture = BatchedFuture.<Integer>create();
-      BatchedRequestIssuer<Integer> issuer = new BatchedRequestIssuer<>(batchedFuture, 2);
-      issuer.setException(thrownException);
-      issuer.setResponse(1);
-      Assert.fail("BatchedFuture should have thrown an exception");
-    } catch (IllegalStateException expected) {
-      Truth.assertThat(expected)
-          .hasMessageThat()
-          .contains("Cannot set both exception and response");
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatcherFactoryTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatcherFactoryTest.java
deleted file mode 100644
index 254ba2831..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatcherFactoryTest.java
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.SquarerBatchingDescriptor;
-
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.FlowControlSettings;
-import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.ThresholdBatcher;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.common.truth.Truth;
-import java.util.List;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatcherFactoryTest {
-  private ScheduledExecutorService batchingExecutor;
-
-  @Before
-  public void setUp() {
-    batchingExecutor = new ScheduledThreadPoolExecutor(1);
-  }
-
-  @After
-  public void tearDown() {
-    batchingExecutor.shutdownNow();
-  }
-
-  @Test
-  public void testGetPushingBatcher() {
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(1))
-            .setElementCountThreshold(2L)
-            .setRequestByteThreshold(1000L)
-            .build();
-    FlowControlSettings flowControlSettings =
-        FlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .build();
-    FlowController flowController = new FlowController(flowControlSettings);
-    BatcherFactory<LabeledIntList, List<Integer>> batcherFactory =
-        new BatcherFactory<>(
-            new SquarerBatchingDescriptor(), batchingSettings, batchingExecutor, flowController);
-    Truth.assertThat(batcherFactory.getBatchingSettings()).isSameInstanceAs(batchingSettings);
-
-    ThresholdBatcher<Batch<LabeledIntList, List<Integer>>> batcherFoo =
-        batcherFactory.getPushingBatcher(new PartitionKey("foo"));
-
-    ThresholdBatcher<Batch<LabeledIntList, List<Integer>>> batcherFoo2 =
-        batcherFactory.getPushingBatcher(new PartitionKey("foo"));
-
-    ThresholdBatcher<Batch<LabeledIntList, List<Integer>>> batcherBar =
-        batcherFactory.getPushingBatcher(new PartitionKey("bar"));
-
-    Truth.assertThat(batcherFoo).isSameInstanceAs(batcherFoo2);
-    Truth.assertThat(batcherFoo).isNotSameInstanceAs(batcherBar);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchingCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchingCallSettingsTest.java
deleted file mode 100644
index baafb1044..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchingCallSettingsTest.java
+++ /dev/null
@@ -1,199 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.collect.Sets;
-import com.google.common.truth.Truth;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatchingCallSettingsTest {
-
-  @Test
-  public void testEmptyBuilder() {
-    @SuppressWarnings("unchecked")
-    BatchingDescriptor<Integer, Integer> batchingDescriptor =
-        Mockito.mock(BatchingDescriptor.class);
-    BatchingCallSettings.Builder<Integer, Integer> builder =
-        BatchingCallSettings.newBuilder(batchingDescriptor);
-
-    Truth.assertThat(builder.getBatchingDescriptor()).isSameInstanceAs(batchingDescriptor);
-    Truth.assertThat(builder.getBatchingSettings()).isNull();
-    Truth.assertThat(builder.getFlowController()).isNull();
-    Truth.assertThat(builder.getRetryableCodes().size()).isEqualTo(0);
-    Truth.assertThat(builder.getRetrySettings()).isNotNull();
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
-    builder.setBatchingSettings(batchingSettings);
-    BatchingCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getBatchingDescriptor()).isSameInstanceAs(batchingDescriptor);
-    Truth.assertThat(settings.getBatchingSettings()).isSameInstanceAs(batchingSettings);
-    Truth.assertThat(settings.getFlowController()).isNotNull();
-    Truth.assertThat(settings.getRetryableCodes().size()).isEqualTo(0);
-    Truth.assertThat(settings.getRetrySettings()).isNotNull();
-  }
-
-  @Test
-  public void testBuilder() {
-    @SuppressWarnings("unchecked")
-    BatchingDescriptor<Integer, Integer> batchingDescriptor =
-        Mockito.mock(BatchingDescriptor.class);
-    BatchingCallSettings.Builder<Integer, Integer> builder =
-        BatchingCallSettings.newBuilder(batchingDescriptor);
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
-    FlowController flowController = Mockito.mock(FlowController.class);
-    Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    builder.setBatchingSettings(batchingSettings);
-    builder.setFlowController(flowController);
-    builder.setRetryableCodes(retryCodes);
-    builder.setRetrySettings(retrySettings);
-
-    Truth.assertThat(builder.getBatchingDescriptor()).isSameInstanceAs(batchingDescriptor);
-    Truth.assertThat(builder.getBatchingSettings()).isSameInstanceAs(batchingSettings);
-    Truth.assertThat(builder.getFlowController()).isSameInstanceAs(flowController);
-    Truth.assertThat(builder.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(builder.getRetrySettings()).isEqualTo(retrySettings);
-
-    BatchingCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getBatchingDescriptor()).isSameInstanceAs(batchingDescriptor);
-    Truth.assertThat(settings.getBatchingSettings()).isSameInstanceAs(batchingSettings);
-    Truth.assertThat(settings.getFlowController()).isSameInstanceAs(flowController);
-    Truth.assertThat(settings.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(settings.getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void testBuilderFromSettings() throws Exception {
-    @SuppressWarnings("unchecked")
-    BatchingDescriptor<Integer, Integer> batchingDescriptor =
-        Mockito.mock(BatchingDescriptor.class);
-    BatchingCallSettings.Builder<Integer, Integer> builder =
-        BatchingCallSettings.newBuilder(batchingDescriptor);
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
-    FlowController flowController = Mockito.mock(FlowController.class);
-    Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    builder.setBatchingSettings(batchingSettings);
-    builder.setFlowController(flowController);
-    builder.setRetryableCodes(retryCodes);
-    builder.setRetrySettings(retrySettings);
-
-    BatchingCallSettings settings = builder.build();
-    BatchingCallSettings.Builder newBuilder = settings.toBuilder();
-
-    Truth.assertThat(newBuilder.getBatchingDescriptor()).isSameInstanceAs(batchingDescriptor);
-    Truth.assertThat(newBuilder.getBatchingSettings()).isSameInstanceAs(batchingSettings);
-    Truth.assertThat(newBuilder.getFlowController()).isSameInstanceAs(flowController);
-    Truth.assertThat(newBuilder.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(newBuilder.getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void testNoFlowControlSettings() throws Exception {
-    @SuppressWarnings("unchecked")
-    BatchingDescriptor<Integer, Integer> batchingDescriptor =
-        Mockito.mock(BatchingDescriptor.class);
-    BatchingCallSettings.Builder<Integer, Integer> builder =
-        BatchingCallSettings.newBuilder(batchingDescriptor);
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
-
-    builder.setBatchingSettings(batchingSettings);
-
-    BatchingCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getFlowController()).isNotNull();
-  }
-
-  @Test
-  public void testToString() {
-    @SuppressWarnings("unchecked")
-    BatchingDescriptor<Integer, Integer> batchingDescriptor =
-        Mockito.mock(BatchingDescriptor.class);
-    BatchingCallSettings.Builder<Integer, Integer> builder =
-        BatchingCallSettings.newBuilder(batchingDescriptor);
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
-    FlowController flowController = Mockito.mock(FlowController.class);
-    Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-
-    builder
-        .setRetryableCodes(retryCodes)
-        .setRetrySettings(retrySettings)
-        .setBatchingSettings(batchingSettings)
-        .setFlowController(flowController);
-
-    Truth.assertThat(builder.build().toString()).contains("retryableCodes=" + retryCodes);
-    Truth.assertThat(builder.build().toString()).contains("retrySettings=" + retrySettings);
-    Truth.assertThat(builder.build().toString()).contains("batchingSettings=" + batchingSettings);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchingCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchingCallableTest.java
deleted file mode 100644
index a0234a441..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchingCallableTest.java
+++ /dev/null
@@ -1,137 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.FlowControlSettings;
-import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.api.gax.rpc.testing.FakeBatchableApi;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.SquarerBatchingDescriptor;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.common.truth.Truth;
-import java.util.List;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatchingCallableTest {
-  private ScheduledExecutorService batchingExecutor;
-
-  @Before
-  public void setUp() {
-    batchingExecutor = new ScheduledThreadPoolExecutor(2);
-  }
-
-  @After
-  public void tearDown() {
-    batchingExecutor.shutdownNow();
-  }
-
-  @Test
-  public void testBatchedCall() throws Exception {
-
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(10))
-            .setElementCountThreshold(2L)
-            .setRequestByteThreshold(1000L)
-            .build();
-    FlowControlSettings flowControlSettings =
-        FlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .build();
-    FlowController flowController = new FlowController(flowControlSettings);
-    BatcherFactory<LabeledIntList, List<Integer>> batcherFactory =
-        new BatcherFactory<>(
-            new SquarerBatchingDescriptor(), batchingSettings, batchingExecutor, flowController);
-
-    BatchingCallable<LabeledIntList, List<Integer>> batchingCallable =
-        new BatchingCallable<>(
-            FakeBatchableApi.callLabeledIntSquarer,
-            FakeBatchableApi.SQUARER_BATCHING_DESC,
-            batcherFactory);
-
-    LabeledIntList request1 = new LabeledIntList("label", 2);
-    ApiFuture<List<Integer>> future1 =
-        batchingCallable.futureCall(request1, FakeCallContext.createDefault());
-    // Assume it won't take 10 seconds (the batching delay threshold) to check the first future
-    Truth.assertThat(future1.isDone()).isFalse();
-
-    LabeledIntList request2 = new LabeledIntList("label", 3);
-    ApiFuture<List<Integer>> future2 =
-        batchingCallable.futureCall(request2, FakeCallContext.createDefault());
-
-    List<Integer> response1 = future1.get();
-    List<Integer> response2 = future2.get();
-
-    Truth.assertThat(response1.size()).isEqualTo(1);
-    Truth.assertThat(response1.get(0)).isEqualTo(2 * 2);
-
-    Truth.assertThat(response2.size()).isEqualTo(1);
-    Truth.assertThat(response2.get(0)).isEqualTo(3 * 3);
-  }
-
-  @Test
-  public void testUnbatchedCall() throws Exception {
-
-    BatchingSettings batchingSettings = BatchingSettings.newBuilder().setIsEnabled(false).build();
-    FlowControlSettings flowControlSettings =
-        FlowControlSettings.newBuilder()
-            .setLimitExceededBehavior(LimitExceededBehavior.Ignore)
-            .build();
-    FlowController flowController = new FlowController(flowControlSettings);
-    BatcherFactory<LabeledIntList, List<Integer>> batcherFactory =
-        new BatcherFactory<>(
-            new SquarerBatchingDescriptor(), batchingSettings, batchingExecutor, flowController);
-
-    BatchingCallable<LabeledIntList, List<Integer>> batchingCallable =
-        new BatchingCallable<>(
-            FakeBatchableApi.callLabeledIntSquarer,
-            FakeBatchableApi.SQUARER_BATCHING_DESC,
-            batcherFactory);
-
-    LabeledIntList request1 = new LabeledIntList("label", 2);
-    ApiFuture<List<Integer>> future1 =
-        batchingCallable.futureCall(request1, FakeCallContext.createDefault());
-    List<Integer> response1 = future1.get();
-
-    Truth.assertThat(response1.size()).isEqualTo(1);
-    Truth.assertThat(response1.get(0)).isEqualTo(2 * 2);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BatchingTest.java b/gax/src/test/java/com/google/api/gax/rpc/BatchingTest.java
deleted file mode 100644
index 2b4a07596..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BatchingTest.java
+++ /dev/null
@@ -1,237 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.SQUARER_BATCHING_DESC;
-import static com.google.api.gax.rpc.testing.FakeBatchableApi.callLabeledIntSquarer;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.batching.BatchingSettings;
-import com.google.api.gax.batching.FlowControlSettings;
-import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
-import com.google.api.gax.batching.TrackedFlowController;
-import com.google.api.gax.rpc.testing.FakeBatchableApi.LabeledIntList;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.common.truth.Truth;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class BatchingTest {
-
-  private ScheduledExecutorService batchingExecutor;
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    batchingExecutor = new ScheduledThreadPoolExecutor(1);
-    clientContext =
-        ClientContext.newBuilder()
-            .setExecutor(batchingExecutor)
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @After
-  public void teardown() {
-    batchingExecutor.shutdownNow();
-  }
-
-  @Test
-  public void batching() throws Exception {
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(1))
-            .setElementCountThreshold(2L)
-            .build();
-    BatchingCallSettings<LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC)
-            .setBatchingSettings(batchingSettings)
-            .build();
-    UnaryCallable<LabeledIntList, List<Integer>> callable =
-        FakeCallableFactory.createBatchingCallable(
-            callLabeledIntSquarer, batchingCallSettings, clientContext);
-    ApiFuture<List<Integer>> f1 = callable.futureCall(new LabeledIntList("one", 1, 2));
-    ApiFuture<List<Integer>> f2 = callable.futureCall(new LabeledIntList("one", 3, 4));
-    Truth.assertThat(f1.get()).isEqualTo(Arrays.asList(1, 4));
-    Truth.assertThat(f2.get()).isEqualTo(Arrays.asList(9, 16));
-  }
-
-  @Test
-  public void batchingWithFlowControl() throws Exception {
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(1))
-            .setElementCountThreshold(4L)
-            .setRequestByteThreshold(null)
-            .setFlowControlSettings(
-                FlowControlSettings.newBuilder()
-                    .setLimitExceededBehavior(LimitExceededBehavior.Block)
-                    .setMaxOutstandingElementCount(10L)
-                    .setMaxOutstandingRequestBytes(10L)
-                    .build())
-            .build();
-    TrackedFlowController trackedFlowController =
-        new TrackedFlowController(batchingSettings.getFlowControlSettings());
-
-    Truth.assertThat(trackedFlowController.getElementsReserved()).isEqualTo(0);
-    Truth.assertThat(trackedFlowController.getElementsReleased()).isEqualTo(0);
-    Truth.assertThat(trackedFlowController.getBytesReserved()).isEqualTo(0);
-    Truth.assertThat(trackedFlowController.getBytesReleased()).isEqualTo(0);
-    Truth.assertThat(trackedFlowController.getCallsToReserve()).isEqualTo(0);
-    Truth.assertThat(trackedFlowController.getCallsToRelease()).isEqualTo(0);
-
-    LabeledIntList requestA = new LabeledIntList("one", 1, 2);
-    LabeledIntList requestB = new LabeledIntList("one", 3, 4);
-
-    BatchingCallSettings<LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC)
-            .setBatchingSettings(batchingSettings)
-            .setFlowController(trackedFlowController)
-            .build();
-    Callables.BatchingCreateResult<LabeledIntList, List<Integer>> batchingCreateResult =
-        Callables.batchingImpl(callLabeledIntSquarer, batchingCallSettings, clientContext);
-    ApiFuture<List<Integer>> f1 =
-        batchingCreateResult
-            .getUnaryCallable()
-            .futureCall(requestA, FakeCallContext.createDefault());
-    ApiFuture<List<Integer>> f2 =
-        batchingCreateResult
-            .getUnaryCallable()
-            .futureCall(requestB, FakeCallContext.createDefault());
-    Truth.assertThat(f1.get()).isEqualTo(Arrays.asList(1, 4));
-    Truth.assertThat(f2.get()).isEqualTo(Arrays.asList(9, 16));
-
-    batchingCreateResult
-        .getBatcherFactory()
-        .getPushingBatcher(SQUARER_BATCHING_DESC.getBatchPartitionKey(requestA))
-        .pushCurrentBatch()
-        .get();
-
-    // Check that the number of bytes is correct even when requests are merged, and the merged
-    // request consumes fewer bytes.
-    Truth.assertThat(trackedFlowController.getElementsReserved()).isEqualTo(4);
-    Truth.assertThat(trackedFlowController.getElementsReleased()).isEqualTo(4);
-    Truth.assertThat(trackedFlowController.getBytesReserved()).isEqualTo(8);
-    Truth.assertThat(trackedFlowController.getBytesReleased()).isEqualTo(8);
-    Truth.assertThat(trackedFlowController.getCallsToReserve()).isEqualTo(2);
-    Truth.assertThat(trackedFlowController.getCallsToRelease()).isEqualTo(1);
-  }
-
-  @Test
-  public void batchingDisabled() throws Exception {
-    BatchingSettings batchingSettings = BatchingSettings.newBuilder().setIsEnabled(false).build();
-
-    BatchingCallSettings<LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC)
-            .setBatchingSettings(batchingSettings)
-            .build();
-    UnaryCallable<LabeledIntList, List<Integer>> callable =
-        FakeCallableFactory.createBatchingCallable(
-            callLabeledIntSquarer, batchingCallSettings, clientContext);
-    ApiFuture<List<Integer>> f1 = callable.futureCall(new LabeledIntList("one", 1, 2));
-    ApiFuture<List<Integer>> f2 = callable.futureCall(new LabeledIntList("one", 3, 4));
-    Truth.assertThat(f1.get()).isEqualTo(Arrays.asList(1, 4));
-    Truth.assertThat(f2.get()).isEqualTo(Arrays.asList(9, 16));
-  }
-
-  @Test
-  public void batchingWithBlockingCallThreshold() throws Exception {
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(1))
-            .setElementCountThreshold(2L)
-            .build();
-    BatchingCallSettings<LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC)
-            .setBatchingSettings(batchingSettings)
-            .build();
-    UnaryCallable<LabeledIntList, List<Integer>> callable =
-        FakeCallableFactory.createBatchingCallable(
-            callLabeledIntSquarer, batchingCallSettings, clientContext);
-    ApiFuture<List<Integer>> f1 = callable.futureCall(new LabeledIntList("one", 1));
-    ApiFuture<List<Integer>> f2 = callable.futureCall(new LabeledIntList("one", 3));
-    Truth.assertThat(f1.get()).isEqualTo(Arrays.asList(1));
-    Truth.assertThat(f2.get()).isEqualTo(Arrays.asList(9));
-  }
-
-  private static UnaryCallable<LabeledIntList, List<Integer>> callLabeledIntExceptionThrower =
-      new UnaryCallable<LabeledIntList, List<Integer>>() {
-        @Override
-        public ApiFuture<List<Integer>> futureCall(LabeledIntList request, ApiCallContext context) {
-          return RetryingTest.<List<Integer>>immediateFailedFuture(
-              new IllegalArgumentException("I FAIL!!"));
-        }
-      };
-
-  @Test
-  public void batchingException() throws Exception {
-    BatchingSettings batchingSettings =
-        BatchingSettings.newBuilder()
-            .setDelayThreshold(Duration.ofSeconds(1))
-            .setElementCountThreshold(2L)
-            .build();
-    BatchingCallSettings<LabeledIntList, List<Integer>> batchingCallSettings =
-        BatchingCallSettings.newBuilder(SQUARER_BATCHING_DESC)
-            .setBatchingSettings(batchingSettings)
-            .build();
-    UnaryCallable<LabeledIntList, List<Integer>> callable =
-        FakeCallableFactory.createBatchingCallable(
-            callLabeledIntExceptionThrower, batchingCallSettings, clientContext);
-    ApiFuture<List<Integer>> f1 = callable.futureCall(new LabeledIntList("one", 1, 2));
-    ApiFuture<List<Integer>> f2 = callable.futureCall(new LabeledIntList("one", 3, 4));
-    try {
-      f1.get();
-      Assert.fail("Expected exception from batching call");
-    } catch (ExecutionException e) {
-      // expected
-    }
-    try {
-      f2.get();
-      Assert.fail("Expected exception from batching call");
-    } catch (ExecutionException e) {
-      // expected
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/BidiStreamingCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/BidiStreamingCallableTest.java
deleted file mode 100644
index 76ecb1d51..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/BidiStreamingCallableTest.java
+++ /dev/null
@@ -1,172 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.FakeStreamingApi.BidiStreamingStashCallable;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import org.junit.Test;
-
-public class BidiStreamingCallableTest {
-  private ClientContext clientContext =
-      ClientContext.newBuilder()
-          .setDefaultCallContext(FakeCallContext.createDefault())
-          .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-          .build();
-
-  @Test
-  public void bidiStreaming_ResponseObserver() {
-    BidiStreamingStashCallable<Integer, Integer> callIntList =
-        new BidiStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    BidiStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createBidiStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    AccumulatingStreamObserver responseObserver = new AccumulatingStreamObserver();
-
-    ClientStream<Integer> stream = callable.splitCall(responseObserver);
-    stream.send(3);
-    stream.send(4);
-    stream.send(5);
-    stream.closeSend();
-
-    assertThat(responseObserver.getValues()).containsExactly(0, 1, 2).inOrder();
-    assertThat(callIntList.getActualRequests()).containsExactly(3, 4, 5).inOrder();
-  }
-
-  @Test
-  public void bidiStreaming_BidiStreamObserver() throws InterruptedException {
-    BidiStreamingStashCallable<Integer, Integer> callIntList =
-        new BidiStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    BidiStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createBidiStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    AccumulatingBidiObserver observer = new AccumulatingBidiObserver(Arrays.asList(3, 4, 5));
-    callable.call(observer);
-
-    assertThat(observer.getResponses()).containsExactly(0, 1, 2).inOrder();
-    assertThat(callIntList.getActualRequests()).containsExactly(3, 4, 5).inOrder();
-  }
-
-  @Test
-  public void bidiStreaming_BidiStream() {
-    BidiStreamingStashCallable<Integer, Integer> callIntList =
-        new BidiStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-    BidiStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createBidiStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    BidiStream<Integer, Integer> stream = callIntList.call();
-    stream.send(3);
-    stream.send(4);
-    stream.send(5);
-    stream.closeSend();
-
-    assertThat(callIntList.getActualRequests()).containsExactly(3, 4, 5).inOrder();
-    assertThat(stream).containsExactly(0, 1, 2).inOrder();
-  }
-
-  private static class AccumulatingBidiObserver implements BidiStreamObserver<Integer, Integer> {
-    private final List<Integer> received = new ArrayList<>();
-    private Throwable error;
-    private final CountDownLatch latch = new CountDownLatch(1);
-
-    private final Iterator<Integer> toSend;
-
-    AccumulatingBidiObserver(Collection<Integer> toSend) {
-      this.toSend = toSend.iterator();
-    }
-
-    @Override
-    public void onStart(StreamController controller) {
-      // no-op
-    }
-
-    @Override
-    public void onResponse(Integer response) {
-      received.add(response);
-    }
-
-    @Override
-    public void onComplete() {
-      latch.countDown();
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      error = t;
-      latch.countDown();
-    }
-
-    @Override
-    public void onReady(ClientStream<Integer> stream) {
-      while (toSend.hasNext()) {
-        if (stream.isSendReady()) {
-          stream.send(toSend.next());
-        } else {
-          // It's OK we haven't consumed the whole iterator;
-          // onReady will be called again when the network becomes free.
-          return;
-        }
-      }
-      // We ran out of things to send.
-      stream.closeSend();
-    }
-
-    List<Integer> getResponses() throws InterruptedException {
-      latch.await();
-      if (error != null) {
-        throw ApiExceptionFactory.createException(error, FakeStatusCode.of(Code.UNKNOWN), false);
-      }
-      return received;
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/CallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/CallableTest.java
deleted file mode 100644
index eaa0be04c..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/CallableTest.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.atLeastOnce;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import org.junit.Rule;
-import org.junit.Test;
-import org.mockito.Mock;
-import org.mockito.Spy;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-import org.threeten.bp.Duration;
-
-public class CallableTest {
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private UnaryCallable<String, String> innerCallable;
-  private SettableApiFuture<String> innerResult;
-
-  @Mock private ServerStreamingCallable<Object, Object> innerServerStreamingCallable;
-
-  private RetrySettings retrySettings =
-      RetrySettings.newBuilder()
-          .setInitialRpcTimeout(Duration.ofMillis(5L))
-          .setMaxRpcTimeout(Duration.ofMillis(5L))
-          .setTotalTimeout(Duration.ofMillis(10L))
-          .build();
-
-  @Spy private ApiCallContext callContext = FakeCallContext.createDefault();
-
-  @Spy
-  private ApiCallContext callContextWithRetrySettings =
-      FakeCallContext.createDefault().withRetrySettings(retrySettings);
-
-  private ClientContext clientContext =
-      ClientContext.newBuilder().setDefaultCallContext(callContext).build();
-
-  @Test
-  public void testNonRetriedCallable() throws Exception {
-    innerResult = SettableApiFuture.create();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-    Duration timeout = Duration.ofMillis(5L);
-
-    UnaryCallSettings<Object, Object> callSettings =
-        UnaryCallSettings.newUnaryCallSettingsBuilder().setSimpleTimeoutNoRetries(timeout).build();
-    UnaryCallable<String, String> callable =
-        Callables.retrying(innerCallable, callSettings, clientContext);
-    innerResult.set("No, my refrigerator is not running!");
-
-    callable.futureCall("Is your refrigerator running?", callContext);
-    verify(callContext, atLeastOnce()).getRetrySettings();
-    verify(callContext).getTimeout();
-    verify(callContext).withTimeout(timeout);
-  }
-
-  @Test
-  public void testNonRetriedCallableWithRetrySettings() throws Exception {
-    innerResult = SettableApiFuture.create();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-
-    UnaryCallSettings<Object, Object> callSettings =
-        UnaryCallSettings.newUnaryCallSettingsBuilder()
-            .setSimpleTimeoutNoRetries(Duration.ofMillis(10L))
-            .build();
-    UnaryCallable<String, String> callable =
-        Callables.retrying(innerCallable, callSettings, clientContext);
-    innerResult.set("No, my refrigerator is not running!");
-
-    Duration timeout = retrySettings.getInitialRpcTimeout();
-
-    callable.futureCall("Is your refrigerator running?", callContextWithRetrySettings);
-
-    verify(callContextWithRetrySettings, atLeastOnce()).getRetrySettings();
-    verify(callContextWithRetrySettings).getTimeout();
-    verify(callContextWithRetrySettings).withTimeout(timeout);
-  }
-
-  @Test
-  public void testNonRetriedServerStreamingCallable() throws Exception {
-    Duration timeout = Duration.ofMillis(5L);
-    ServerStreamingCallSettings<Object, Object> callSettings =
-        ServerStreamingCallSettings.newBuilder().setSimpleTimeoutNoRetries(timeout).build();
-    ServerStreamingCallable<Object, Object> callable =
-        Callables.retrying(innerServerStreamingCallable, callSettings, clientContext);
-
-    callable.call("Is your refrigerator running?", callContext);
-
-    verify(callContext, atLeastOnce()).getRetrySettings();
-    verify(callContext).getTimeout();
-    verify(callContext).withTimeout(timeout);
-  }
-
-  @Test
-  public void testNonRetriedServerStreamingCallableWithRetrySettings() throws Exception {
-    ServerStreamingCallSettings<Object, Object> callSettings =
-        ServerStreamingCallSettings.newBuilder()
-            .setSimpleTimeoutNoRetries(Duration.ofMillis(10L))
-            .build();
-    ServerStreamingCallable<Object, Object> callable =
-        Callables.retrying(innerServerStreamingCallable, callSettings, clientContext);
-
-    Duration timeout = retrySettings.getTotalTimeout();
-
-    callable.call("Is your refrigerator running?", callContextWithRetrySettings);
-
-    verify(callContextWithRetrySettings, atLeastOnce()).getRetrySettings();
-    verify(callContextWithRetrySettings).getTimeout();
-    verify(callContextWithRetrySettings).withTimeout(timeout);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/CancellationHelpers.java b/gax/src/test/java/com/google/api/gax/rpc/CancellationHelpers.java
deleted file mode 100644
index 446090bac..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/CancellationHelpers.java
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.locks.LockSupport;
-
-/**
- * CancellationHelpers provides helpers for cancellation tests which perform cancellation in a
- * deterministic way.
- */
-public class CancellationHelpers {
-
-  public static void cancelInThreadAfterLatchCountDown(
-      final ApiFuture<?> resultFuture, final CountDownLatch latch) {
-    Thread t =
-        new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                try {
-                  latch.await();
-                  while (!resultFuture.cancel(true) && !resultFuture.isDone()) {
-                    LockSupport.parkNanos(1000L);
-                  }
-                } catch (InterruptedException e) {
-                  Thread.currentThread().interrupt();
-                }
-              }
-            });
-    t.start();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/CancellationTest.java b/gax/src/test/java/com/google/api/gax/rpc/CancellationTest.java
deleted file mode 100644
index bb36d863c..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/CancellationTest.java
+++ /dev/null
@@ -1,264 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.core.RecordingScheduler;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class CancellationTest {
-
-  @SuppressWarnings("unchecked")
-  private UnaryCallable<Integer, Integer> callInt = Mockito.mock(UnaryCallable.class);
-
-  private static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(2L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(2L))
-          .setInitialRpcTimeout(Duration.ofMillis(2L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(2L))
-          .setTotalTimeout(Duration.ofMillis(20L))
-          .build();
-
-  private static final RetrySettings SLOW_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(3000L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(3000L))
-          .setInitialRpcTimeout(Duration.ofMillis(3000L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(3000L))
-          .setTotalTimeout(Duration.ofMillis(3000L))
-          .build();
-
-  private FakeApiClock fakeClock;
-  private RecordingScheduler executor;
-  private ClientContext clientContext;
-
-  @Before
-  public void resetClock() {
-    fakeClock = new FakeApiClock(System.nanoTime());
-    executor = RecordingScheduler.create(fakeClock);
-    clientContext =
-        ClientContext.newBuilder()
-            .setExecutor(executor)
-            .setClock(fakeClock)
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @After
-  public void teardown() {
-    executor.shutdownNow();
-  }
-
-  @Test
-  public void cancellationBeforeGetOnRetryingCallable() throws Exception {
-    try {
-      Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-          .thenReturn(SettableApiFuture.<Integer>create());
-
-      UnaryCallSettings<Integer, Integer> callSettings =
-          RetryingTest.createSettings(FAST_RETRY_SETTINGS);
-      UnaryCallable<Integer, Integer> callable =
-          FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-
-      ApiFuture<Integer> resultFuture = callable.futureCall(0);
-      resultFuture.cancel(true);
-      resultFuture.get();
-      Assert.fail("Callable should have thrown an exception");
-    } catch (CancellationException expected) {
-      Truth.assertThat(expected).hasMessageThat().contains("Task was cancelled");
-    }
-  }
-
-  private static class CancellationTrackingFuture<RespT> extends AbstractApiFuture<RespT> {
-    private volatile boolean cancelled = false;
-
-    public static <RespT> CancellationTrackingFuture<RespT> create() {
-      return new CancellationTrackingFuture<>();
-    }
-
-    private CancellationTrackingFuture() {}
-
-    @Override
-    protected void interruptTask() {
-      cancelled = true;
-    }
-
-    public boolean isCancelled() {
-      return cancelled;
-    }
-  }
-
-  private static class LatchCountDownFutureCallable<RequestT, ResponseT>
-      extends UnaryCallable<RequestT, ResponseT> {
-    private CountDownLatch callLatch;
-    private List<ApiFuture<ResponseT>> injectedFutures;
-
-    @SuppressWarnings("unchecked")
-    public LatchCountDownFutureCallable(
-        CountDownLatch callLatch, ApiFuture<ResponseT> injectedFuture) {
-      this(callLatch, Lists.newArrayList(injectedFuture));
-    }
-
-    public LatchCountDownFutureCallable(
-        CountDownLatch callLatch, List<ApiFuture<ResponseT>> injectedFutures) {
-      this.callLatch = callLatch;
-      this.injectedFutures = Lists.newArrayList(injectedFutures);
-    }
-
-    @Override
-    public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-      callLatch.countDown();
-      return injectedFutures.remove(0);
-    }
-  }
-
-  @Test
-  public void cancellationDuringFirstCall() throws Exception {
-    CancellationTrackingFuture<Integer> innerFuture = CancellationTrackingFuture.<Integer>create();
-    CountDownLatch callIssuedLatch = new CountDownLatch(1);
-    UnaryCallable<Integer, Integer> innerCallable =
-        new LatchCountDownFutureCallable<>(callIssuedLatch, innerFuture);
-
-    UnaryCallSettings<Integer, Integer> callSettings =
-        RetryingTest.createSettings(FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(
-            innerCallable,
-            callSettings,
-            clientContext.toBuilder().setExecutor(new ScheduledThreadPoolExecutor(1)).build());
-
-    ApiFuture<Integer> resultFuture = callable.futureCall(0);
-    CancellationHelpers.cancelInThreadAfterLatchCountDown(resultFuture, callIssuedLatch);
-    CancellationException gotException = null;
-    try {
-      resultFuture.get();
-    } catch (CancellationException e) {
-      gotException = e;
-    }
-    Truth.assertThat(gotException).isNotNull();
-    Truth.assertThat(innerFuture.isCancelled()).isTrue();
-  }
-
-  @Test
-  public void cancellationDuringRetryDelay() throws Exception {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    CancellationTrackingFuture<Integer> innerFuture = CancellationTrackingFuture.create();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(innerFuture);
-
-    CountDownLatch retryScheduledLatch = new CountDownLatch(1);
-    LatchCountDownScheduler scheduler = LatchCountDownScheduler.get(retryScheduledLatch, 0L, 0L);
-    UnaryCallSettings<Integer, Integer> callSettings =
-        RetryingTest.createSettings(SLOW_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(
-            callInt, callSettings, clientContext.toBuilder().setExecutor(scheduler).build());
-
-    ApiFuture<Integer> resultFuture = callable.futureCall(0);
-    CancellationHelpers.cancelInThreadAfterLatchCountDown(resultFuture, retryScheduledLatch);
-    CancellationException gotException = null;
-    try {
-      resultFuture.get();
-    } catch (CancellationException e) {
-      gotException = e;
-    }
-    Truth.assertThat(gotException).isNotNull();
-    Truth.assertThat(resultFuture.isDone()).isTrue();
-    Truth.assertThat(resultFuture.isCancelled()).isTrue();
-    Truth.assertThat(innerFuture.isCancelled()).isFalse();
-
-    scheduler.shutdownNow();
-  }
-
-  @Test
-  public void cancellationDuringSecondCall() throws Exception {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    ApiFuture<Integer> failingFuture = RetryingTest.immediateFailedFuture(throwable);
-    CancellationTrackingFuture<Integer> innerFuture = CancellationTrackingFuture.create();
-    CountDownLatch callIssuedLatch = new CountDownLatch(2);
-    @SuppressWarnings("unchecked")
-    UnaryCallable<Integer, Integer> innerCallable =
-        new LatchCountDownFutureCallable<>(
-            callIssuedLatch, Lists.newArrayList(failingFuture, innerFuture));
-
-    UnaryCallSettings<Integer, Integer> callSettings =
-        RetryingTest.createSettings(FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(
-            innerCallable,
-            callSettings,
-            clientContext.toBuilder().setExecutor(new ScheduledThreadPoolExecutor(1)).build());
-
-    ApiFuture<Integer> resultFuture = callable.futureCall(0);
-    CancellationHelpers.cancelInThreadAfterLatchCountDown(resultFuture, callIssuedLatch);
-    CancellationException gotException = null;
-    try {
-      resultFuture.get();
-    } catch (CancellationException e) {
-      gotException = e;
-    }
-    Truth.assertThat(gotException).isNotNull();
-    Truth.assertThat(resultFuture.isDone()).isTrue();
-    Truth.assertThat(resultFuture.isCancelled()).isTrue();
-    Truth.assertThat(innerFuture.isDone()).isTrue();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/CheckingAttemptCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/CheckingAttemptCallableTest.java
deleted file mode 100644
index 92554616b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/CheckingAttemptCallableTest.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.mockito.stubbing.Answer;
-import org.threeten.bp.Duration;
-
-@RunWith(MockitoJUnitRunner.class)
-public class CheckingAttemptCallableTest {
-  @Mock UnaryCallable<String, String> mockInnerCallable;
-  ArgumentCaptor<ApiCallContext> capturedCallContext;
-  @Mock RetryingFuture<String> mockExternalFuture;
-  TimedAttemptSettings currentAttemptSettings;
-
-  @Before
-  public void setUp() {
-    capturedCallContext = ArgumentCaptor.forClass(ApiCallContext.class);
-    Mockito.when(mockInnerCallable.futureCall(Mockito.<String>any(), capturedCallContext.capture()))
-        .thenReturn(SettableApiFuture.<String>create());
-
-    currentAttemptSettings =
-        TimedAttemptSettings.newBuilder()
-            .setGlobalSettings(RetrySettings.newBuilder().build())
-            .setAttemptCount(0)
-            .setOverallAttemptCount(0)
-            .setFirstAttemptStartTimeNanos(0)
-            .setRetryDelay(Duration.ofSeconds(1))
-            .setRandomizedRetryDelay(Duration.ofSeconds(1))
-            .setRpcTimeout(Duration.ZERO)
-            .build();
-
-    Mockito.when(mockExternalFuture.getAttemptSettings())
-        .thenAnswer(
-            new Answer<TimedAttemptSettings>() {
-              @Override
-              public TimedAttemptSettings answer(InvocationOnMock invocation) throws Throwable {
-                return currentAttemptSettings;
-              }
-            });
-  }
-
-  @Test
-  public void testRpcTimeout() {
-    CheckingAttemptCallable<String, String> callable =
-        new CheckingAttemptCallable<>(mockInnerCallable, FakeCallContext.createDefault());
-    callable.setExternalFuture(mockExternalFuture);
-
-    // Make sure that the rpc timeout is set
-    Duration timeout = Duration.ofSeconds(10);
-    currentAttemptSettings = currentAttemptSettings.toBuilder().setRpcTimeout(timeout).build();
-
-    callable.call();
-
-    assertThat(capturedCallContext.getValue().getTimeout()).isEqualTo(timeout);
-
-    // Make sure that subsequent attempts can extend the time out
-    Duration longerTimeout = Duration.ofSeconds(20);
-    currentAttemptSettings =
-        currentAttemptSettings.toBuilder().setRpcTimeout(longerTimeout).build();
-    callable.call();
-    assertThat(capturedCallContext.getValue().getTimeout()).isEqualTo(longerTimeout);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ClientContextTest.java b/gax/src/test/java/com/google/api/gax/rpc/ClientContextTest.java
deleted file mode 100644
index 7fe418dd6..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ClientContextTest.java
+++ /dev/null
@@ -1,772 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-import com.google.api.core.ApiClock;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.CredentialsProvider;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.core.FixedCredentialsProvider;
-import com.google.api.gax.core.FixedExecutorProvider;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import com.google.api.gax.rpc.mtls.MtlsProvider.MtlsEndpointUsagePolicy;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeClientSettings;
-import com.google.api.gax.rpc.testing.FakeMtlsProvider;
-import com.google.api.gax.rpc.testing.FakeStubSettings;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.GoogleCredentials;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.truth.Truth;
-import java.io.IOException;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class ClientContextTest {
-
-  private static class InterceptingExecutor extends ScheduledThreadPoolExecutor {
-    boolean shutdownCalled = false;
-
-    public InterceptingExecutor(int corePoolSize) {
-      super(corePoolSize);
-    }
-
-    public void shutdown() {
-      shutdownCalled = true;
-    }
-  }
-
-  private static class FakeExecutorProvider implements ExecutorProvider {
-    ScheduledExecutorService executor;
-    boolean shouldAutoClose;
-
-    FakeExecutorProvider(ScheduledExecutorService executor, boolean shouldAutoClose) {
-      this.executor = executor;
-      this.shouldAutoClose = shouldAutoClose;
-    }
-
-    @Override
-    public boolean shouldAutoClose() {
-      return shouldAutoClose;
-    }
-
-    @Override
-    public ScheduledExecutorService getExecutor() {
-      return executor;
-    }
-  }
-
-  private static class FakeTransportProvider implements TransportChannelProvider {
-    final Executor executor;
-    final FakeTransportChannel transport;
-    final boolean shouldAutoClose;
-    final Map<String, String> headers;
-    final Credentials credentials;
-
-    FakeTransportProvider(
-        FakeTransportChannel transport,
-        Executor executor,
-        boolean shouldAutoClose,
-        Map<String, String> headers,
-        Credentials credentials) {
-      this.transport = transport;
-      this.executor = executor;
-      this.shouldAutoClose = shouldAutoClose;
-      this.headers = headers;
-      this.transport.setHeaders(headers);
-      this.credentials = credentials;
-    }
-
-    @Override
-    public boolean shouldAutoClose() {
-      return shouldAutoClose;
-    }
-
-    @Override
-    public boolean needsExecutor() {
-      return executor == null;
-    }
-
-    @Override
-    public TransportChannelProvider withExecutor(ScheduledExecutorService executor) {
-      return withExecutor((Executor) executor);
-    }
-
-    @Override
-    public TransportChannelProvider withExecutor(Executor executor) {
-      return new FakeTransportProvider(
-          this.transport, executor, this.shouldAutoClose, this.headers, this.credentials);
-    }
-
-    @Override
-    public boolean needsHeaders() {
-      return headers == null;
-    }
-
-    @Override
-    public TransportChannelProvider withHeaders(Map<String, String> headers) {
-      return new FakeTransportProvider(
-          this.transport, this.executor, this.shouldAutoClose, headers, this.credentials);
-    }
-
-    @Override
-    public boolean needsEndpoint() {
-      return false;
-    }
-
-    @Override
-    public TransportChannelProvider withEndpoint(String endpoint) {
-      return this;
-    }
-
-    @Override
-    public boolean acceptsPoolSize() {
-      return false;
-    }
-
-    @Override
-    public TransportChannelProvider withPoolSize(int size) {
-      throw new UnsupportedOperationException(
-          "FakeTransportProvider doesn't allow pool size customization");
-    }
-
-    @Override
-    public TransportChannel getTransportChannel() throws IOException {
-      if (needsCredentials()) {
-        throw new IllegalStateException("Needs Credentials");
-      }
-      transport.setExecutor(executor);
-      return transport;
-    }
-
-    @Override
-    public String getTransportName() {
-      return "FakeTransport";
-    }
-
-    @Override
-    public boolean needsCredentials() {
-      return credentials == null;
-    }
-
-    @Override
-    public TransportChannelProvider withCredentials(Credentials credentials) {
-      return new FakeTransportProvider(
-          this.transport, this.executor, this.shouldAutoClose, this.headers, credentials);
-    }
-  }
-
-  @Test
-  public void testNoAutoCloseContextNeedsNoExecutor() throws Exception {
-    runTest(false, false, false, false);
-  }
-
-  @Test
-  public void testWithAutoCloseContextNeedsNoExecutor() throws Exception {
-    runTest(true, false, false, false);
-  }
-
-  @Test
-  public void testWithAutoCloseContextNeedsExecutor() throws Exception {
-    runTest(true, true, false, false);
-  }
-
-  @Test
-  public void testNeedsHeaders() throws Exception {
-    runTest(false, false, true, false);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testNeedsHeadersCollision() throws Exception {
-    runTest(false, false, true, true);
-  }
-
-  private void runTest(
-      boolean shouldAutoClose,
-      boolean contextNeedsExecutor,
-      boolean needHeaders,
-      boolean headersCollision)
-      throws Exception {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    ExecutorProvider executorProvider = new FakeExecutorProvider(executor, shouldAutoClose);
-    Map<String, String> headers = ImmutableMap.of("k1", "v1", "k2", "v2");
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(
-            transportChannel,
-            contextNeedsExecutor ? null : executor,
-            shouldAutoClose,
-            needHeaders ? null : headers,
-            null);
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiClock clock = Mockito.mock(ApiClock.class);
-    Watchdog watchdog =
-        Watchdog.create(
-            Mockito.mock(ApiClock.class),
-            Duration.ZERO,
-            Mockito.mock(ScheduledExecutorService.class));
-    Duration watchdogCheckInterval = Duration.ofSeconds(11);
-
-    builder.setExecutorProvider(executorProvider);
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(FixedCredentialsProvider.create(credentials));
-    builder.setWatchdogProvider(FixedWatchdogProvider.create(watchdog));
-    builder.setWatchdogCheckInterval(watchdogCheckInterval);
-    builder.setClock(clock);
-
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(headerProvider.getHeaders()).thenReturn(ImmutableMap.of("k1", "v1"));
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-    if (headersCollision) {
-      Mockito.when(internalHeaderProvider.getHeaders()).thenReturn(ImmutableMap.of("k1", "v1"));
-    } else {
-      Mockito.when(internalHeaderProvider.getHeaders()).thenReturn(ImmutableMap.of("k2", "v2"));
-    }
-
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-
-    FakeClientSettings settings = builder.build();
-    ClientContext clientContext = ClientContext.create(settings);
-
-    Truth.assertThat(clientContext.getExecutor()).isSameInstanceAs(executor);
-    Truth.assertThat(clientContext.getTransportChannel()).isSameInstanceAs(transportChannel);
-
-    FakeTransportChannel actualChannel = (FakeTransportChannel) clientContext.getTransportChannel();
-    assert actualChannel != null;
-    Truth.assertThat(actualChannel.getHeaders()).isEqualTo(headers);
-    Truth.assertThat(clientContext.getCredentials()).isSameInstanceAs(credentials);
-    Truth.assertThat(clientContext.getClock()).isSameInstanceAs(clock);
-    Truth.assertThat(clientContext.getStreamWatchdog()).isSameInstanceAs(watchdog);
-    Truth.assertThat(clientContext.getStreamWatchdogCheckInterval())
-        .isEqualTo(watchdogCheckInterval);
-
-    Truth.assertThat(clientContext.getHeaders()).isEqualTo(ImmutableMap.of("k1", "v1"));
-    Truth.assertThat(clientContext.getInternalHeaders()).isEqualTo(ImmutableMap.of("k2", "v2"));
-
-    Truth.assertThat(executor.shutdownCalled).isFalse();
-    Truth.assertThat(transportChannel.isShutdown()).isFalse();
-
-    List<BackgroundResource> resources = clientContext.getBackgroundResources();
-
-    if (!resources.isEmpty()) {
-      // This is slightly too implementation-specific, but we need to ensure that executor is shut
-      // down after the transportChannel: https://github.com/googleapis/gax-java/issues/785
-      Truth.assertThat(resources.size()).isEqualTo(2);
-      Truth.assertThat(transportChannel.isShutdown()).isNotEqualTo(shouldAutoClose);
-      Truth.assertThat(executor.shutdownCalled).isNotEqualTo(shouldAutoClose);
-      resources.get(0).shutdown();
-      Truth.assertThat(transportChannel.isShutdown()).isEqualTo(shouldAutoClose);
-      Truth.assertThat(executor.shutdownCalled).isNotEqualTo(shouldAutoClose);
-      resources.get(1).shutdown();
-      Truth.assertThat(transportChannel.isShutdown()).isEqualTo(shouldAutoClose);
-      Truth.assertThat(executor.shutdownCalled).isEqualTo(shouldAutoClose);
-    }
-  }
-
-  @Test
-  public void testWatchdogProvider() throws IOException {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-    ApiClock clock = Mockito.mock(ApiClock.class);
-
-    builder.setClock(clock);
-    builder.setCredentialsProvider(
-        FixedCredentialsProvider.create(Mockito.mock(Credentials.class)));
-    builder.setExecutorProvider(new FakeExecutorProvider(executor, true));
-    builder.setTransportChannelProvider(transportProvider);
-
-    Duration watchdogCheckInterval = Duration.ofSeconds(11);
-    builder.setWatchdogProvider(
-        InstantiatingWatchdogProvider.create()
-            .withClock(clock)
-            .withCheckInterval(watchdogCheckInterval)
-            .withExecutor(executor));
-    builder.setWatchdogCheckInterval(watchdogCheckInterval);
-
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(headerProvider.getHeaders()).thenReturn(ImmutableMap.of("k1", "v1"));
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-
-    Mockito.when(internalHeaderProvider.getHeaders()).thenReturn(ImmutableMap.of("k2", "v2"));
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-
-    ClientContext context = ClientContext.create(builder.build());
-    List<BackgroundResource> resources = context.getBackgroundResources();
-    assertThat(resources.get(2)).isInstanceOf(Watchdog.class);
-  }
-
-  @Test
-  public void testMergeHeaders_getQuotaProjectIdFromHeadersProvider() throws IOException {
-    final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-    final String QUOTA_PROJECT_ID_FROM_SETTINGS = "quota_project_id_from_settings";
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(headerProvider.getHeaders()).thenReturn(ImmutableMap.of("header_k1", "v1"));
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(internalHeaderProvider.getHeaders())
-        .thenReturn(ImmutableMap.of("internal_header_k1", "v1"));
-
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(
-        FixedCredentialsProvider.create(Mockito.mock(Credentials.class)));
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-    builder.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_SETTINGS);
-
-    ClientContext context = ClientContext.create(builder.build());
-    List<BackgroundResource> resources = context.getBackgroundResources();
-    FakeTransportChannel fakeTransportChannel = (FakeTransportChannel) resources.get(0);
-    assertThat(fakeTransportChannel.getHeaders().size())
-        .isEqualTo(
-            headerProvider.getHeaders().size() + internalHeaderProvider.getHeaders().size() + 1);
-    assertThat(fakeTransportChannel.getHeaders().get(QUOTA_PROJECT_ID_KEY))
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_SETTINGS);
-  }
-
-  @Test
-  public void testMergeHeaders_getQuotaProjectIdFromSettings() throws IOException {
-    final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-    final String QUOTA_PROJECT_ID_FROM_HEADERS = "quota_project_id_from_headers";
-    final String QUOTA_PROJECT_ID_FROM_INTERNAL_HEADERS = "quota_project_id_from_internal_headers";
-    final String QUOTA_PROJECT_ID_FROM_SETTINGS = "quota_project_id_from_settings";
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-
-    HeaderProvider headerProvider =
-        new HeaderProvider() {
-          @Override
-          public Map<String, String> getHeaders() {
-            return ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_HEADERS, "k2", "v2");
-          }
-        };
-    HeaderProvider internalHeaderProvider =
-        new HeaderProvider() {
-          @Override
-          public Map<String, String> getHeaders() {
-            return ImmutableMap.of(
-                QUOTA_PROJECT_ID_KEY,
-                QUOTA_PROJECT_ID_FROM_INTERNAL_HEADERS,
-                "internal_header_k1",
-                "v1");
-          }
-        };
-
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(
-        FixedCredentialsProvider.create(Mockito.mock(Credentials.class)));
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-    builder.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_SETTINGS);
-
-    ClientContext context = ClientContext.create(builder.build());
-    List<BackgroundResource> resources = context.getBackgroundResources();
-    FakeTransportChannel fakeTransportChannel = (FakeTransportChannel) resources.get(0);
-    assertThat(fakeTransportChannel.getHeaders().size())
-        .isEqualTo(
-            headerProvider.getHeaders().size() + internalHeaderProvider.getHeaders().size() - 1);
-    assertThat(fakeTransportChannel.getHeaders().get(QUOTA_PROJECT_ID_KEY))
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_SETTINGS);
-  }
-
-  @Test
-  public void testMergeHeaders_noQuotaProjectIdSet() throws IOException {
-    final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(headerProvider.getHeaders()).thenReturn(ImmutableMap.of("header_k1", "v1"));
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-    Mockito.when(internalHeaderProvider.getHeaders())
-        .thenReturn(ImmutableMap.of("internal_header_k1", "v1"));
-
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(
-        FixedCredentialsProvider.create(Mockito.mock(Credentials.class)));
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-
-    ClientContext context = ClientContext.create(builder.build());
-    List<BackgroundResource> resources = context.getBackgroundResources();
-    FakeTransportChannel fakeTransportChannel = (FakeTransportChannel) resources.get(0);
-    assertThat(fakeTransportChannel.getHeaders().size())
-        .isEqualTo(headerProvider.getHeaders().size() + internalHeaderProvider.getHeaders().size());
-    assertThat(fakeTransportChannel.getHeaders().containsKey(QUOTA_PROJECT_ID_KEY)).isFalse();
-  }
-
-  @Test
-  public void testHidingQuotaProjectId_quotaSetFromSetting() throws IOException {
-    final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-    final String QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE = "quota_project_id_from_credentials";
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-    Map<String, List<String>> metaDataWithQuota =
-        ImmutableMap.of(
-            "k1",
-            Collections.singletonList("v1"),
-            QUOTA_PROJECT_ID_KEY,
-            Collections.singletonList(QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE));
-    final Credentials credentialsWithQuotaProjectId = Mockito.mock(GoogleCredentials.class);
-    Mockito.when(credentialsWithQuotaProjectId.getRequestMetadata(null))
-        .thenReturn(metaDataWithQuota);
-    HeaderProvider headerProviderWithQuota = Mockito.mock(HeaderProvider.class);
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-
-    builder.setExecutorProvider(new FakeExecutorProvider(executor, true));
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(
-        new CredentialsProvider() {
-          @Override
-          public Credentials getCredentials() throws IOException {
-            return credentialsWithQuotaProjectId;
-          }
-        });
-    builder.setHeaderProvider(headerProviderWithQuota);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-    builder.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE);
-
-    ClientContext clientContext = ClientContext.create(builder.build());
-    assertThat(clientContext.getCredentials().getRequestMetadata().size())
-        .isEqualTo(metaDataWithQuota.size() - 1);
-    assertThat(
-            clientContext.getCredentials().getRequestMetadata().containsKey(QUOTA_PROJECT_ID_KEY))
-        .isFalse();
-  }
-
-  @Test
-  public void testHidingQuotaProjectId_noQuotaSetFromSetting() throws IOException {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    InterceptingExecutor executor = new InterceptingExecutor(1);
-    FakeTransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FakeTransportProvider transportProvider =
-        new FakeTransportProvider(transportChannel, executor, true, null, null);
-    Map<String, List<String>> metaData = ImmutableMap.of("k1", Collections.singletonList("v1"));
-    final Credentials credentialsWithoutQuotaProjectId = Mockito.mock(GoogleCredentials.class);
-    Mockito.when(credentialsWithoutQuotaProjectId.getRequestMetadata(null)).thenReturn(metaData);
-    HeaderProvider headerProviderWithQuota = Mockito.mock(HeaderProvider.class);
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-
-    builder.setExecutorProvider(new FakeExecutorProvider(executor, true));
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(
-        new CredentialsProvider() {
-          @Override
-          public Credentials getCredentials() throws IOException {
-            return credentialsWithoutQuotaProjectId;
-          }
-        });
-    builder.setHeaderProvider(headerProviderWithQuota);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-
-    ClientContext clientContext = ClientContext.create(builder.build());
-    assertThat(clientContext.getCredentials().getRequestMetadata(null)).isEqualTo(metaData);
-  }
-
-  @Test
-  public void testUserAgentInternalOnly() throws Exception {
-    TransportChannelProvider transportChannelProvider =
-        new FakeTransportProvider(
-            FakeTransportChannel.create(new FakeChannel()), null, true, null, null);
-
-    ClientSettings.Builder builder =
-        new FakeClientSettings.Builder()
-            .setExecutorProvider(
-                FixedExecutorProvider.create(Mockito.mock(ScheduledExecutorService.class)))
-            .setTransportChannelProvider(transportChannelProvider)
-            .setCredentialsProvider(
-                FixedCredentialsProvider.create(Mockito.mock(GoogleCredentials.class)));
-
-    builder.setInternalHeaderProvider(FixedHeaderProvider.create("user-agent", "internal-agent"));
-
-    ClientContext clientContext = ClientContext.create(builder.build());
-    FakeTransportChannel transportChannel =
-        (FakeTransportChannel) clientContext.getTransportChannel();
-
-    assertThat(transportChannel.getHeaders()).containsEntry("user-agent", "internal-agent");
-  }
-
-  @Test
-  public void testUserAgentExternalOnly() throws Exception {
-    TransportChannelProvider transportChannelProvider =
-        new FakeTransportProvider(
-            FakeTransportChannel.create(new FakeChannel()), null, true, null, null);
-
-    ClientSettings.Builder builder =
-        new FakeClientSettings.Builder()
-            .setExecutorProvider(
-                FixedExecutorProvider.create(Mockito.mock(ScheduledExecutorService.class)))
-            .setTransportChannelProvider(transportChannelProvider)
-            .setCredentialsProvider(
-                FixedCredentialsProvider.create(Mockito.mock(GoogleCredentials.class)));
-
-    builder.setHeaderProvider(FixedHeaderProvider.create("user-agent", "user-supplied-agent"));
-
-    ClientContext clientContext = ClientContext.create(builder.build());
-    FakeTransportChannel transportChannel =
-        (FakeTransportChannel) clientContext.getTransportChannel();
-
-    assertThat(transportChannel.getHeaders()).containsEntry("user-agent", "user-supplied-agent");
-  }
-
-  @Test
-  public void testUserAgentConcat() throws Exception {
-    TransportChannelProvider transportChannelProvider =
-        new FakeTransportProvider(
-            FakeTransportChannel.create(new FakeChannel()), null, true, null, null);
-
-    ClientSettings.Builder builder =
-        new FakeClientSettings.Builder()
-            .setExecutorProvider(
-                FixedExecutorProvider.create(Mockito.mock(ScheduledExecutorService.class)))
-            .setTransportChannelProvider(transportChannelProvider)
-            .setCredentialsProvider(
-                FixedCredentialsProvider.create(Mockito.mock(GoogleCredentials.class)));
-
-    builder.setHeaderProvider(FixedHeaderProvider.create("user-agent", "user-supplied-agent"));
-    builder.setInternalHeaderProvider(FixedHeaderProvider.create("user-agent", "internal-agent"));
-
-    ClientContext clientContext = ClientContext.create(builder.build());
-    FakeTransportChannel transportChannel =
-        (FakeTransportChannel) clientContext.getTransportChannel();
-
-    assertThat(transportChannel.getHeaders())
-        .containsEntry("user-agent", "user-supplied-agent internal-agent");
-  }
-
-  private static String endpoint = "https://foo.googleapis.com";
-  private static String mtlsEndpoint = "https://foo.mtls.googleapis.com";
-
-  @Test
-  public void testAutoUseMtlsEndpoint() throws IOException {
-    // Test the case client certificate exists and mTLS endpoint is selected.
-    boolean switchToMtlsEndpointAllowed = true;
-    MtlsProvider provider =
-        new FakeMtlsProvider(
-            true,
-            MtlsEndpointUsagePolicy.AUTO,
-            FakeMtlsProvider.createTestMtlsKeyStore(),
-            "",
-            false);
-    String endpointSelected =
-        ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-    assertEquals(mtlsEndpoint, endpointSelected);
-  }
-
-  @Test
-  public void testEndpointNotOverridable() throws IOException {
-    // Test the case that switching to mTLS endpoint is not allowed so the original endpoint is
-    // selected.
-    boolean switchToMtlsEndpointAllowed = false;
-    MtlsProvider provider =
-        new FakeMtlsProvider(
-            true,
-            MtlsEndpointUsagePolicy.AUTO,
-            FakeMtlsProvider.createTestMtlsKeyStore(),
-            "",
-            false);
-    String endpointSelected =
-        ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-    assertEquals(endpoint, endpointSelected);
-  }
-
-  @Test
-  public void testNoClientCertificate() throws IOException {
-    // Test the case that client certificates doesn't exists so the original endpoint is selected.
-    boolean switchToMtlsEndpointAllowed = true;
-    MtlsProvider provider =
-        new FakeMtlsProvider(true, MtlsEndpointUsagePolicy.AUTO, null, "", false);
-    String endpointSelected =
-        ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-    assertEquals(endpoint, endpointSelected);
-  }
-
-  @Test
-  public void testAlwaysUseMtlsEndpoint() throws IOException {
-    // Test the case that mTLS endpoint is always used.
-    boolean switchToMtlsEndpointAllowed = true;
-    MtlsProvider provider =
-        new FakeMtlsProvider(false, MtlsEndpointUsagePolicy.ALWAYS, null, "", false);
-    String endpointSelected =
-        ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-    assertEquals(mtlsEndpoint, endpointSelected);
-  }
-
-  @Test
-  public void testNeverUseMtlsEndpoint() throws IOException {
-    // Test the case that mTLS endpoint is never used.
-    boolean switchToMtlsEndpointAllowed = true;
-    MtlsProvider provider =
-        new FakeMtlsProvider(
-            true,
-            MtlsEndpointUsagePolicy.NEVER,
-            FakeMtlsProvider.createTestMtlsKeyStore(),
-            "",
-            false);
-    String endpointSelected =
-        ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-    assertEquals(endpoint, endpointSelected);
-  }
-
-  @Test
-  public void testGetKeyStoreThrows() throws IOException {
-    // Test the case that getKeyStore throws exceptions.
-    try {
-      boolean switchToMtlsEndpointAllowed = true;
-      MtlsProvider provider =
-          new FakeMtlsProvider(true, MtlsEndpointUsagePolicy.AUTO, null, "", true);
-      ClientContext.getEndpoint(endpoint, mtlsEndpoint, switchToMtlsEndpointAllowed, provider);
-      fail("should throw an exception");
-    } catch (IOException e) {
-      assertTrue(
-          "expected getKeyStore to throw an exception",
-          e.getMessage().contains("getKeyStore throws exception"));
-    }
-  }
-
-  @Test
-  public void testSwitchToMtlsEndpointAllowed() throws IOException {
-    StubSettings settings = new FakeStubSettings.Builder().setEndpoint(endpoint).build();
-    assertFalse(settings.getSwitchToMtlsEndpointAllowed());
-    assertEquals(endpoint, settings.getEndpoint());
-
-    settings =
-        new FakeStubSettings.Builder()
-            .setEndpoint(endpoint)
-            .setSwitchToMtlsEndpointAllowed(true)
-            .build();
-    assertTrue(settings.getSwitchToMtlsEndpointAllowed());
-    assertEquals(endpoint, settings.getEndpoint());
-
-    // Test setEndpoint sets the switchToMtlsEndpointAllowed value to false.
-    settings =
-        new FakeStubSettings.Builder()
-            .setSwitchToMtlsEndpointAllowed(true)
-            .setEndpoint(endpoint)
-            .build();
-    assertFalse(settings.getSwitchToMtlsEndpointAllowed());
-    assertEquals(endpoint, settings.getEndpoint());
-  }
-
-  @Test
-  public void testExecutorSettings() throws Exception {
-    TransportChannelProvider transportChannelProvider =
-        new FakeTransportProvider(
-            FakeTransportChannel.create(new FakeChannel()), null, true, null, null);
-
-    ClientSettings.Builder builder =
-        new FakeClientSettings.Builder()
-            .setTransportChannelProvider(transportChannelProvider)
-            .setCredentialsProvider(
-                FixedCredentialsProvider.create(Mockito.mock(GoogleCredentials.class)));
-
-    // By default, if executor is not set, channel provider should not have an executor set
-    ClientContext context = ClientContext.create(builder.build());
-    FakeTransportChannel transportChannel = (FakeTransportChannel) context.getTransportChannel();
-    assertThat(transportChannel.getExecutor()).isNull();
-
-    ExecutorProvider channelExecutorProvider =
-        FixedExecutorProvider.create(Mockito.mock(ScheduledExecutorService.class));
-    builder.setTransportChannelProvider(
-        transportChannelProvider.withExecutor((Executor) channelExecutorProvider.getExecutor()));
-    context = ClientContext.create(builder.build());
-    transportChannel = (FakeTransportChannel) context.getTransportChannel();
-    assertThat(transportChannel.getExecutor())
-        .isSameInstanceAs(channelExecutorProvider.getExecutor());
-
-    ExecutorProvider executorProvider =
-        FixedExecutorProvider.create(Mockito.mock(ScheduledExecutorService.class));
-    assertThat(channelExecutorProvider.getExecutor())
-        .isNotSameInstanceAs(executorProvider.getExecutor());
-
-    // For backward compatibility, if executor is set from stubSettings.setExecutor, and transport
-    // channel already has an executor, the ExecutorProvider set in stubSettings won't override
-    // transport channel's executor
-    builder.setExecutorProvider(executorProvider);
-    context = ClientContext.create(builder.build());
-    transportChannel = (FakeTransportChannel) context.getTransportChannel();
-    assertThat(transportChannel.getExecutor())
-        .isSameInstanceAs(channelExecutorProvider.getExecutor());
-
-    // For backward compatibility, if executor is set from stubSettings.setExecutor, and transport
-    // channel doesn't have an executor, transport channel will get the executor from
-    // stubSettings.setExecutor
-    builder.setExecutorProvider(executorProvider);
-    builder.setTransportChannelProvider(
-        new FakeTransportProvider(
-            FakeTransportChannel.create(new FakeChannel()), null, true, null, null));
-    context = ClientContext.create(builder.build());
-    transportChannel = (FakeTransportChannel) context.getTransportChannel();
-    assertThat(transportChannel.getExecutor()).isSameInstanceAs(executorProvider.getExecutor());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ClientSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/ClientSettingsTest.java
deleted file mode 100644
index b39d59cbd..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ClientSettingsTest.java
+++ /dev/null
@@ -1,545 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.fail;
-
-import com.google.api.core.ApiClock;
-import com.google.api.core.ApiFunction;
-import com.google.api.core.NanoClock;
-import com.google.api.gax.core.CredentialsProvider;
-import com.google.api.gax.core.ExecutorProvider;
-import com.google.api.gax.core.FixedCredentialsProvider;
-import com.google.api.gax.core.FixedExecutorProvider;
-import com.google.api.gax.core.InstantiatingExecutorProvider;
-import com.google.api.gax.core.NoCredentialsProvider;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeClientSettings;
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.GoogleCredentials;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.truth.Truth;
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ScheduledExecutorService;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class ClientSettingsTest {
-  private static final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-  private static final String QUOTA_PROJECT_ID_FROM_HEADER_VALUE = "quota_project_id_from_headers";
-  private static final String QUOTA_PROJECT_ID_FROM_BUILDERS = "quota_project_id_from_builders";
-  private static final String QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE =
-      "quota_project_id_from_internal_headers";
-  private static final String QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE =
-      "quota_project_id_from_credentials";
-  private static final String QUOTA_PROJECT_ID_FROM_CONTEXT =
-      "quota_project_id_from_client_context";
-  private static final String JSON_KEY_QUOTA_PROJECT_ID =
-      "{\n"
-          + "  \"private_key_id\": \"somekeyid\",\n"
-          + "  \"private_key\": \"-----BEGIN PRIVATE KEY-----\\nMIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggS"
-          + "kAgEAAoIBAQC+K2hSuFpAdrJI\\nnCgcDz2M7t7bjdlsadsasad+fvRSW6TjNQZ3p5LLQY1kSZRqBqylRkzteMOyHg"
-          + "aR\\n0Pmxh3ILCND5men43j3h4eDbrhQBuxfEMalkG92sL+PNQSETY2tnvXryOvmBRwa/\\nQP/9dJfIkIDJ9Fw9N4"
-          + "Bhhhp6mCcRpdQjV38H7JsyJ7lih/oNjECgYAt\\nknddadwkwewcVxHFhcZJO+XWf6ofLUXpRwiTZakGMn8EE1uVa2"
-          + "LgczOjwWHGi99MFjxSer5m9\\n1tCa3/KEGKiS/YL71JvjwX3mb+cewlkcmweBKZHM2JPTk0ZednFSpVZMtycjkbLa"
-          + "\\ndYOS8V85AgMBewECggEBAKksaldajfDZDV6nGqbFjMiizAKJolr/M3OQw16K6o3/\\n0S31xIe3sSlgW0+UbYlF"
-          + "4U8KifhManD1apVSC3csafaspP4RZUHFhtBywLO9pR5c\\nr6S5aLp+gPWFyIp1pfXbWGvc5VY/v9x7ya1VEa6rXvL"
-          + "sKupSeWAW4tMj3eo/64ge\\nsdaceaLYw52KeBYiT6+vpsnYrEkAHO1fF/LavbLLOFJmFTMxmsNaG0tuiJHgjshB\\"
-          + "n82DpMCbXG9YcCgI/DbzuIjsdj2JC1cascSP//3PmefWysucBQe7Jryb6NQtASmnv\\nCdDw/0jmZTEjpe4S1lxfHp"
-          + "lAhHFtdgYTvyYtaLZiVVkCgYEA8eVpof2rceecw/I6\\n5ng1q3Hl2usdWV/4mZMvR0fOemacLLfocX6IYxT1zA1FF"
-          + "JlbXSRsJMf/Qq39mOR2\\nSpW+hr4jCoHeRVYLgsbggtrevGmILAlNoqCMpGZ6vDmJpq6ECV9olliDvpPgWOP+\\nm"
-          + "YPDreFBGxWvQrADNbRt2dmGsrsCgYEAyUHqB2wvJHFqdmeBsaacewzV8x9WgmeX\\ngUIi9REwXlGDW0Mz50dxpxcK"
-          + "CAYn65+7TCnY5O/jmL0VRxU1J2mSWyWTo1C+17L0\\n3fUqjxL1pkefwecxwecvC+gFFYdJ4CQ/MHHXU81Lwl1iWdF"
-          + "Cd2UoGddYaOF+KNeM\\nHC7cmqra+JsCgYEAlUNywzq8nUg7282E+uICfCB0LfwejuymR93CtsFgb7cRd6ak\\nECR"
-          + "8FGfCpH8ruWJINllbQfcHVCX47ndLZwqv3oVFKh6pAS/vVI4dpOepP8++7y1u\\ncoOvtreXCX6XqfrWDtKIvv0vjl"
-          + "HBhhhp6mCcRpdQjV38H7JsyJ7lih/oNjECgYAt\\nkndj5uNl5SiuVxHFhcZJO+XWf6ofLUregtevZakGMn8EE1uVa"
-          + "2AY7eafmoU/nZPT\\n00YB0TBATdCbn/nBSuKDESkhSg9s2GEKQZG5hBmL5uCMfo09z3SfxZIhJdlerreP\\nJ7gSi"
-          + "dI12N+EZxYd4xIJh/HFDgp7RRO87f+WJkofMQKBgGTnClK1VMaCRbJZPriw\\nEfeFCoOX75MxKwXs6xgrw4W//AYG"
-          + "GUjDt83lD6AZP6tws7gJ2IwY/qP7+lyhjEqN\\nHtfPZRGFkGZsdaksdlaksd323423d+15/UvrlRSFPNj1tWQmNKk"
-          + "XyRDW4IG1Oa2p\\nrALStNBx5Y9t0/LQnFI4w3aG\\n-----END PRIVATE KEY-----\\n\",\n"
-          + "  \"project_id\": \"someprojectid\",\n"
-          + "  \"client_email\": \"someclientid@developer.gserviceaccount.com\",\n"
-          + "  \"client_id\": \"someclientid.apps.googleusercontent.com\",\n"
-          + "  \"type\": \"service_account\",\n"
-          + "  \"quota_project_id\": \""
-          + QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE
-          + "\"\n"
-          + "}";
-
-  private static final GoogleCredentials credentialsWithQuotaProject =
-      loadCredentials(JSON_KEY_QUOTA_PROJECT_ID);
-
-  @Test
-  public void testEmptyBuilder() throws Exception {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-    Truth.assertThat(builder.getExecutorProvider()).isNull();
-    Truth.assertThat(builder.getBackgroundExecutorProvider())
-        .isInstanceOf(InstantiatingExecutorProvider.class);
-    Truth.assertThat(builder.getTransportChannelProvider()).isNull();
-    Truth.assertThat(builder.getCredentialsProvider()).isInstanceOf(NoCredentialsProvider.class);
-    Truth.assertThat(builder.getClock()).isInstanceOf(NanoClock.class);
-    Truth.assertThat(builder.getHeaderProvider()).isInstanceOf(NoHeaderProvider.class);
-    Truth.assertThat(builder.getInternalHeaderProvider()).isInstanceOf(NoHeaderProvider.class);
-    Truth.assertThat(builder.getWatchdogProvider())
-        .isInstanceOf(InstantiatingWatchdogProvider.class);
-    Truth.assertThat(builder.getWatchdogCheckInterval()).isGreaterThan(Duration.ZERO);
-    Truth.assertThat(builder.getQuotaProjectId()).isNull();
-
-    FakeClientSettings settings = builder.build();
-    Truth.assertThat(settings.getExecutorProvider())
-        .isSameInstanceAs(builder.getExecutorProvider());
-    Truth.assertThat(settings.getBackgroundExecutorProvider())
-        .isSameInstanceAs(builder.getBackgroundExecutorProvider());
-    Truth.assertThat(settings.getTransportChannelProvider())
-        .isSameInstanceAs(builder.getTransportChannelProvider());
-    Truth.assertThat(settings.getCredentialsProvider())
-        .isSameInstanceAs(builder.getCredentialsProvider());
-    Truth.assertThat(settings.getClock()).isSameInstanceAs(builder.getClock());
-    Truth.assertThat(settings.getHeaderProvider()).isSameInstanceAs(builder.getHeaderProvider());
-    Truth.assertThat(settings.getInternalHeaderProvider())
-        .isSameInstanceAs(builder.getInternalHeaderProvider());
-    Truth.assertThat(settings.getWatchdogProvider())
-        .isInstanceOf(InstantiatingWatchdogProvider.class);
-    Truth.assertThat(settings.getWatchdogCheckInterval()).isGreaterThan(Duration.ZERO);
-    Truth.assertThat((settings.getQuotaProjectId())).isSameInstanceAs(builder.getQuotaProjectId());
-
-    String settingsString = settings.toString();
-    Truth.assertThat(settingsString).contains("executorProvider");
-    Truth.assertThat(settingsString).contains("backgroundExecutorProvider");
-    Truth.assertThat(settingsString).contains("transportChannelProvider");
-    Truth.assertThat(settingsString).contains("credentialsProvider");
-    Truth.assertThat(settingsString).contains("clock");
-    Truth.assertThat(settingsString).contains("headerProvider");
-    Truth.assertThat(settingsString).contains("watchdogProvider");
-    Truth.assertThat(settingsString).contains("watchdogCheckInterval");
-    Truth.assertThat(settingsString).contains(("quotaProjectId"));
-  }
-
-  @Test
-  public void testBuilder() throws Exception {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    ExecutorProvider executorProvider = Mockito.mock(ExecutorProvider.class);
-    TransportChannelProvider transportProvider = Mockito.mock(TransportChannelProvider.class);
-    CredentialsProvider credentialsProvider = Mockito.mock(CredentialsProvider.class);
-    ApiClock clock = Mockito.mock(ApiClock.class);
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-    WatchdogProvider watchdogProvider = Mockito.mock(WatchdogProvider.class);
-    Duration watchdogCheckInterval = Duration.ofSeconds(13);
-    String quotaProjectId = "test_quota_project_id";
-
-    builder.setExecutorProvider(executorProvider);
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(credentialsProvider);
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-    builder.setClock(clock);
-    builder.setWatchdogProvider(watchdogProvider);
-    builder.setWatchdogCheckInterval(watchdogCheckInterval);
-    builder.setQuotaProjectId(quotaProjectId);
-
-    // For backward compatibility, backgroundExecutorProvider is set to executorProvider
-    Truth.assertThat(builder.getExecutorProvider()).isSameInstanceAs(executorProvider);
-    Truth.assertThat(builder.getBackgroundExecutorProvider()).isSameInstanceAs(executorProvider);
-    Truth.assertThat(builder.getTransportChannelProvider()).isSameInstanceAs(transportProvider);
-    Truth.assertThat(builder.getCredentialsProvider()).isSameInstanceAs(credentialsProvider);
-    Truth.assertThat(builder.getClock()).isSameInstanceAs(clock);
-    Truth.assertThat(builder.getHeaderProvider()).isSameInstanceAs(headerProvider);
-    Truth.assertThat(builder.getInternalHeaderProvider()).isSameInstanceAs(internalHeaderProvider);
-    Truth.assertThat(builder.getWatchdogProvider()).isSameInstanceAs(watchdogProvider);
-    Truth.assertThat(builder.getWatchdogCheckInterval()).isSameInstanceAs(watchdogCheckInterval);
-    Truth.assertThat(builder.getQuotaProjectId()).isEqualTo(quotaProjectId);
-
-    String builderString = builder.toString();
-    Truth.assertThat(builderString).contains("executorProvider");
-    Truth.assertThat(builderString).contains("backgroundExecutorProvider");
-    Truth.assertThat(builderString).contains("transportChannelProvider");
-    Truth.assertThat(builderString).contains("credentialsProvider");
-    Truth.assertThat(builderString).contains("clock");
-    Truth.assertThat(builderString).contains("headerProvider");
-    Truth.assertThat(builderString).contains("internalHeaderProvider");
-    Truth.assertThat(builderString).contains("watchdogProvider");
-    Truth.assertThat(builderString).contains("watchdogCheckInterval");
-    Truth.assertThat(builderString).contains("quotaProjectId");
-  }
-
-  @Test
-  public void testBuilderFromClientContext() throws Exception {
-    final String QUOTA_PROJECT_ID_FROM_CONTEXT = "some_quota_project_id_from_context";
-    ApiClock clock = Mockito.mock(ApiClock.class);
-    ApiCallContext callContext = FakeCallContext.createDefault();
-    Map<String, String> headers = Collections.singletonMap("spiffykey", "spiffyvalue");
-    Watchdog watchdog =
-        Watchdog.create(
-            Mockito.mock(ApiClock.class),
-            Duration.ZERO,
-            Mockito.mock(ScheduledExecutorService.class));
-    Duration watchdogCheckInterval = Duration.ofSeconds(12);
-
-    ClientContext clientContext =
-        ClientContext.newBuilder()
-            .setExecutor(Mockito.mock(ScheduledExecutorService.class))
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setCredentials(Mockito.mock(Credentials.class))
-            .setClock(clock)
-            .setDefaultCallContext(callContext)
-            .setHeaders(headers)
-            .setStreamWatchdog(watchdog)
-            .setStreamWatchdogCheckInterval(watchdogCheckInterval)
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .build();
-
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder(clientContext);
-
-    Truth.assertThat(builder.getExecutorProvider()).isInstanceOf(FixedExecutorProvider.class);
-    Truth.assertThat(builder.getBackgroundExecutorProvider())
-        .isInstanceOf(FixedExecutorProvider.class);
-    Truth.assertThat(builder.getExecutorProvider())
-        .isSameInstanceAs(builder.getBackgroundExecutorProvider());
-    Truth.assertThat(builder.getTransportChannelProvider())
-        .isInstanceOf(FixedTransportChannelProvider.class);
-    Truth.assertThat(builder.getCredentialsProvider()).isInstanceOf(FixedCredentialsProvider.class);
-    Truth.assertThat(builder.getClock()).isSameInstanceAs(clock);
-    Truth.assertThat(builder.getHeaderProvider().getHeaders())
-        .containsEntry("spiffykey", "spiffyvalue");
-    Truth.assertThat(builder.getWatchdogProvider()).isInstanceOf(FixedWatchdogProvider.class);
-    Truth.assertThat(builder.getWatchdogProvider().getWatchdog()).isSameInstanceAs(watchdog);
-    Truth.assertThat(builder.getWatchdogCheckInterval()).isEqualTo(watchdogCheckInterval);
-    Truth.assertThat(builder.getQuotaProjectId()).isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-  }
-
-  @Test
-  public void testBuilderFromSettings() throws Exception {
-    FakeClientSettings.Builder builder = new FakeClientSettings.Builder();
-
-    ExecutorProvider executorProvider = Mockito.mock(ExecutorProvider.class);
-    TransportChannelProvider transportProvider = Mockito.mock(TransportChannelProvider.class);
-    CredentialsProvider credentialsProvider = Mockito.mock(CredentialsProvider.class);
-    ApiClock clock = Mockito.mock(ApiClock.class);
-    HeaderProvider headerProvider = Mockito.mock(HeaderProvider.class);
-    HeaderProvider internalHeaderProvider = Mockito.mock(HeaderProvider.class);
-    WatchdogProvider watchdogProvider = Mockito.mock(WatchdogProvider.class);
-    Duration watchdogCheckInterval = Duration.ofSeconds(14);
-    String quotaProjectId = "test_builder_from_settings_quotaProjectId";
-
-    builder.setExecutorProvider(executorProvider);
-    builder.setTransportChannelProvider(transportProvider);
-    builder.setCredentialsProvider(credentialsProvider);
-    builder.setClock(clock);
-    builder.setHeaderProvider(headerProvider);
-    builder.setInternalHeaderProvider(internalHeaderProvider);
-    builder.setWatchdogProvider(watchdogProvider);
-    builder.setWatchdogCheckInterval(watchdogCheckInterval);
-    builder.setQuotaProjectId(quotaProjectId);
-
-    FakeClientSettings settings = builder.build();
-    FakeClientSettings.Builder newBuilder = new FakeClientSettings.Builder(settings);
-
-    Truth.assertThat(newBuilder.getExecutorProvider()).isSameInstanceAs(executorProvider);
-    Truth.assertThat(newBuilder.getBackgroundExecutorProvider()).isSameInstanceAs(executorProvider);
-    Truth.assertThat(newBuilder.getTransportChannelProvider()).isSameInstanceAs(transportProvider);
-    Truth.assertThat(newBuilder.getCredentialsProvider()).isSameInstanceAs(credentialsProvider);
-    Truth.assertThat(newBuilder.getClock()).isSameInstanceAs(clock);
-    Truth.assertThat(newBuilder.getHeaderProvider()).isSameInstanceAs(headerProvider);
-    Truth.assertThat(newBuilder.getInternalHeaderProvider())
-        .isSameInstanceAs(internalHeaderProvider);
-    Truth.assertThat(newBuilder.getWatchdogProvider()).isSameInstanceAs(watchdogProvider);
-    Truth.assertThat(newBuilder.getWatchdogCheckInterval()).isEqualTo(watchdogCheckInterval);
-    Truth.assertThat(newBuilder.getQuotaProjectId()).isEqualTo(quotaProjectId);
-  }
-
-  @Test
-  public void testApplyToAllUnaryMethods() throws Exception {
-    List<UnaryCallSettings.Builder<?, ?>> builders = new ArrayList<>();
-    builders.add(UnaryCallSettings.newUnaryCallSettingsBuilder());
-    builders.add(UnaryCallSettings.newUnaryCallSettingsBuilder());
-    // using an array to have a mutable integer
-    final int[] count = {0};
-    ClientSettings.Builder.applyToAllUnaryMethods(
-        builders,
-        new ApiFunction<UnaryCallSettings.Builder<?, ?>, Void>() {
-          @Override
-          public Void apply(UnaryCallSettings.Builder<?, ?> input) {
-            if (count[0] == 0) {
-              input.setRetryableCodes(StatusCode.Code.UNAVAILABLE);
-            } else {
-              input.setRetryableCodes(StatusCode.Code.DEADLINE_EXCEEDED);
-            }
-            count[0] += 1;
-            return null;
-          }
-        });
-
-    Truth.assertThat(builders.get(0).getRetryableCodes())
-        .containsExactly(StatusCode.Code.UNAVAILABLE);
-    Truth.assertThat(builders.get(1).getRetryableCodes())
-        .containsExactly(StatusCode.Code.DEADLINE_EXCEEDED);
-  }
-
-  static GoogleCredentials loadCredentials(String credentialFile) {
-    try {
-      InputStream keyStream = new ByteArrayInputStream(credentialFile.getBytes());
-      return GoogleCredentials.fromStream(keyStream);
-    } catch (IOException e) {
-      fail("Couldn't create fake JSON credentials.");
-    }
-    return null;
-  }
-
-  @Test
-  public void testBuilderFromSettings_QuotaProjectId() {
-
-    CredentialsProvider credentialsProvider_no_quota = Mockito.mock(CredentialsProvider.class);
-    HeaderProvider headerProvider_no_quota = Mockito.mock(HeaderProvider.class);
-    HeaderProvider internalHeaderProvider_no_quota = Mockito.mock(HeaderProvider.class);
-    HeaderProvider headerProvider_with_quota =
-        new HeaderProvider() {
-          @Override
-          public Map<String, String> getHeaders() {
-            return Collections.singletonMap(
-                QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_HEADER_VALUE);
-          }
-        };
-    HeaderProvider internalHeaderProvider_with_quota =
-        new HeaderProvider() {
-          @Override
-          public Map<String, String> getHeaders() {
-            return Collections.singletonMap(
-                QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE);
-          }
-        };
-    CredentialsProvider credentialsProvider_with_quota =
-        new CredentialsProvider() {
-          @Override
-          public Credentials getCredentials() throws IOException {
-            return credentialsWithQuotaProject;
-          }
-        };
-
-    // Case for setting quota_project_id from builder only
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaOnly = new FakeClientSettings.Builder();
-    builder_setQuotaOnly.setCredentialsProvider(credentialsProvider_no_quota);
-    builder_setQuotaOnly.setHeaderProvider(headerProvider_no_quota);
-    builder_setQuotaOnly.setInternalHeaderProvider(internalHeaderProvider_no_quota);
-    builder_setQuotaOnly.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_BUILDERS);
-
-    // Case for setting quota_project_id from HeaderProvider Only
-    // expect value is from HeaderProvider
-    FakeClientSettings.Builder builder_setQuotaFromHeadersOnly = new FakeClientSettings.Builder();
-    builder_setQuotaFromHeadersOnly.setHeaderProvider(headerProvider_with_quota);
-
-    // Case for setting quota_project_id from HeaderProvider and set from builders
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaFromHeadersAndBuilders =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromHeadersOnly.setHeaderProvider(headerProvider_with_quota);
-    builder_setQuotaFromHeadersAndBuilders.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_BUILDERS);
-
-    // Case for setting quota_project_id from InternalHeaderProvider and set from builders
-    // expect value is from InternalHeaderProvider
-    FakeClientSettings.Builder builder_setQuotaFromInternalHeadersOnly =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromInternalHeadersOnly.setInternalHeaderProvider(
-        internalHeaderProvider_with_quota);
-
-    // Case for setting quota_project_id from InternalHeaderProvider and set from builders
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaFromInternalHeadersAndBuilders =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromInternalHeadersAndBuilders.setInternalHeaderProvider(
-        internalHeaderProvider_with_quota);
-    builder_setQuotaFromInternalHeadersAndBuilders.setQuotaProjectId(
-        QUOTA_PROJECT_ID_FROM_BUILDERS);
-
-    // Case for setting quota_project_id from CredentialProvider Only
-    // expect value is from CredentialProvider
-    FakeClientSettings.Builder builder_setQuotaFromCredentialsProvider =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromCredentialsProvider.setCredentialsProvider(credentialsProvider_with_quota);
-
-    // Case for setting quota_project_id from CredentialProvider and Builders
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaFromCredentialsProviderAndBuilder =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromCredentialsProviderAndBuilder.setCredentialsProvider(
-        credentialsProvider_with_quota);
-    builder_setQuotaFromCredentialsProviderAndBuilder.setQuotaProjectId(
-        QUOTA_PROJECT_ID_FROM_BUILDERS);
-
-    // Case for setting quota_project_id from All three sources
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaFromAllSources = new FakeClientSettings.Builder();
-    builder_setQuotaFromAllSources.setHeaderProvider(headerProvider_with_quota);
-    builder_setQuotaFromAllSources.setInternalHeaderProvider(headerProvider_with_quota);
-    builder_setQuotaFromAllSources.setCredentialsProvider(credentialsProvider_with_quota);
-    builder_setQuotaFromAllSources.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_BUILDERS);
-
-    // Case for setting quota_project_id from All three sources but set from builders first
-    // expect value is from builders
-    FakeClientSettings.Builder builder_setQuotaFromAllSourcesOrder =
-        new FakeClientSettings.Builder();
-    builder_setQuotaFromAllSourcesOrder.setQuotaProjectId(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    builder_setQuotaFromAllSourcesOrder.setHeaderProvider(headerProvider_with_quota);
-    builder_setQuotaFromAllSourcesOrder.setInternalHeaderProvider(headerProvider_with_quota);
-    builder_setQuotaFromAllSourcesOrder.setCredentialsProvider(credentialsProvider_with_quota);
-
-    Truth.assertThat(builder_setQuotaOnly.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    Truth.assertThat(builder_setQuotaFromHeadersOnly.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_HEADER_VALUE);
-    Truth.assertThat(builder_setQuotaFromHeadersAndBuilders.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    Truth.assertThat((builder_setQuotaFromInternalHeadersOnly).getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE);
-    Truth.assertThat(builder_setQuotaFromInternalHeadersAndBuilders.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    Truth.assertThat(builder_setQuotaFromCredentialsProviderAndBuilder.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    Truth.assertThat(builder_setQuotaFromAllSources.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-    Truth.assertThat(builder_setQuotaFromAllSourcesOrder.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_BUILDERS);
-  }
-
-  @Test
-  public void testBuilderFromClientContext_QuotaProjectId() {
-    ApiCallContext callContext = FakeCallContext.createDefault();
-
-    ClientContext clientContextQuotaOnly =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .build();
-    FakeClientSettings.Builder builderQuotaOnly =
-        new FakeClientSettings.Builder(clientContextQuotaOnly);
-
-    ClientContext clientContextCredentialOnly =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setCredentials(credentialsWithQuotaProject)
-            .build();
-    FakeClientSettings.Builder builderCredentialOnly =
-        new FakeClientSettings.Builder(clientContextCredentialOnly);
-
-    ClientContext clientContextCredentialAndQuota =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setCredentials(credentialsWithQuotaProject)
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .build();
-    FakeClientSettings.Builder builderCredentialAndQuota =
-        new FakeClientSettings.Builder(clientContextCredentialAndQuota);
-
-    ClientContext clientContextHeadersOnly =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setHeaders(ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_HEADER_VALUE))
-            .build();
-    FakeClientSettings.Builder builderHeadersOnly =
-        new FakeClientSettings.Builder(clientContextHeadersOnly);
-
-    ClientContext clientContextHeadersAndQuota =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .setHeaders(ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_HEADER_VALUE))
-            .build();
-    FakeClientSettings.Builder builderHeadersAndQuota =
-        new FakeClientSettings.Builder(clientContextHeadersAndQuota);
-
-    ClientContext clientContextInternalHeadersOnly =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setInternalHeaders(
-                ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE))
-            .build();
-    FakeClientSettings.Builder builderInternalHeadersOnly =
-        new FakeClientSettings.Builder(clientContextInternalHeadersOnly);
-
-    ClientContext clientContextInternalHeadersAndQuota =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setInternalHeaders(
-                ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE))
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .build();
-    FakeClientSettings.Builder builderInternalHeadersAndQuota =
-        new FakeClientSettings.Builder(clientContextInternalHeadersAndQuota);
-
-    ClientContext clientContextQuotaFromAllSources =
-        ClientContext.newBuilder()
-            .setTransportChannel(Mockito.mock(TransportChannel.class))
-            .setDefaultCallContext(callContext)
-            .setHeaders(
-                ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE))
-            .setCredentials(credentialsWithQuotaProject)
-            .setQuotaProjectId(QUOTA_PROJECT_ID_FROM_CONTEXT)
-            .setInternalHeaders(
-                ImmutableMap.of(QUOTA_PROJECT_ID_KEY, QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE))
-            .build();
-    FakeClientSettings.Builder builderQuotaFromAllSources =
-        new FakeClientSettings.Builder(clientContextQuotaFromAllSources);
-
-    Truth.assertThat(builderQuotaOnly.getQuotaProjectId()).isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-    Truth.assertThat(builderCredentialOnly.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE);
-    Truth.assertThat(builderCredentialAndQuota.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-    Truth.assertThat(builderHeadersOnly.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_HEADER_VALUE);
-    Truth.assertThat(builderHeadersAndQuota.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-    Truth.assertThat(builderInternalHeadersOnly.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_INTERNAL_HEADER_VALUE);
-    Truth.assertThat(builderInternalHeadersAndQuota.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-    Truth.assertThat(builderQuotaFromAllSources.getQuotaProjectId())
-        .isEqualTo(QUOTA_PROJECT_ID_FROM_CONTEXT);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ErrorDetailsTest.java b/gax/src/test/java/com/google/api/gax/rpc/ErrorDetailsTest.java
deleted file mode 100644
index 8edef41bf..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ErrorDetailsTest.java
+++ /dev/null
@@ -1,234 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertThrows;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import com.google.protobuf.Any;
-import com.google.protobuf.ByteString;
-import com.google.protobuf.Duration;
-import com.google.rpc.BadRequest;
-import com.google.rpc.BadRequest.FieldViolation;
-import com.google.rpc.DebugInfo;
-import com.google.rpc.ErrorInfo;
-import com.google.rpc.Help;
-import com.google.rpc.Help.Link;
-import com.google.rpc.LocalizedMessage;
-import com.google.rpc.PreconditionFailure;
-import com.google.rpc.QuotaFailure;
-import com.google.rpc.QuotaFailure.Violation;
-import com.google.rpc.RequestInfo;
-import com.google.rpc.ResourceInfo;
-import com.google.rpc.RetryInfo;
-import java.util.Collections;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ErrorDetailsTest {
-
-  private static final ErrorInfo ERROR_INFO =
-      ErrorInfo.newBuilder()
-          .setDomain("googleapis.com")
-          .setReason("SERVICE_DISABLED")
-          .putAllMetadata(Collections.emptyMap())
-          .build();
-
-  private static final RetryInfo RETRY_INFO =
-      RetryInfo.newBuilder().setRetryDelay(Duration.newBuilder().setSeconds(213).build()).build();
-
-  private static final DebugInfo DEBUG_INFO =
-      DebugInfo.newBuilder()
-          .setDetail("No more details available")
-          .addStackEntries("Does not matter")
-          .build();
-
-  private static final QuotaFailure QUOTA_FAILURE =
-      QuotaFailure.newBuilder()
-          .addViolations(
-              Violation.newBuilder()
-                  .setDescription("new violation")
-                  .setSubject("This is a breaking news")
-                  .build())
-          .build();
-
-  private static final PreconditionFailure PRECONDITION_FAILURE =
-      PreconditionFailure.newBuilder()
-          .addViolations(
-              PreconditionFailure.Violation.newBuilder()
-                  .setDescription("new violation")
-                  .setSubject("This is a breaking news")
-                  .setType("Unknown")
-                  .build())
-          .build();
-
-  private static final BadRequest BAD_REQUEST =
-      BadRequest.newBuilder()
-          .addFieldViolations(
-              FieldViolation.newBuilder()
-                  .setDescription("new field violation")
-                  .setField("unknown field")
-                  .build())
-          .build();
-
-  private static final RequestInfo REQUEST_INFO =
-      RequestInfo.newBuilder()
-          .setRequestId("ukajsdkansdk123")
-          .setServingData("no data available")
-          .build();
-
-  private static final ResourceInfo RESOURCE_INFO =
-      ResourceInfo.newBuilder()
-          .setDescription("not available")
-          .setResourceName("my resource")
-          .setResourceType("mystery")
-          .setOwner("myself")
-          .build();
-
-  private static final Help HELP =
-      Help.newBuilder()
-          .addLinks(Link.newBuilder().setDescription("new link").setUrl("https://abc.com").build())
-          .build();
-
-  private static final LocalizedMessage LOCALIZED_MESSAGE =
-      LocalizedMessage.newBuilder().setLocale("en").setMessage("nothing").build();
-
-  ErrorDetails errorDetails;
-
-  @Before
-  public void setUp() throws Exception {
-    ImmutableList<Any> rawErrorMessages =
-        ImmutableList.of(
-            Any.pack(ERROR_INFO),
-            Any.pack(RETRY_INFO),
-            Any.pack(DEBUG_INFO),
-            Any.pack(QUOTA_FAILURE),
-            Any.pack(PRECONDITION_FAILURE),
-            Any.pack(BAD_REQUEST),
-            Any.pack(REQUEST_INFO),
-            Any.pack(RESOURCE_INFO),
-            Any.pack(HELP),
-            Any.pack(LOCALIZED_MESSAGE));
-
-    errorDetails = ErrorDetails.builder().setRawErrorMessages(rawErrorMessages).build();
-  }
-
-  @Test
-  public void unpack_shouldReturnNullIfRawErrorMessagesIsNull() {
-    errorDetails = ErrorDetails.builder().setRawErrorMessages(null).build();
-
-    Truth.assertThat(errorDetails.unpack(ErrorInfo.class)).isNull();
-  }
-
-  @Test
-  public void unpack_shouldReturnNullIfErrorMessageTypeDoesNotExist() {
-    errorDetails =
-        ErrorDetails.builder().setRawErrorMessages(ImmutableList.of(Any.pack(ERROR_INFO))).build();
-
-    Truth.assertThat(errorDetails.unpack(DebugInfo.class)).isNull();
-  }
-
-  @Test
-  public void unpack_shouldThrowExceptionIfUnpackingErrorMassageFailed() {
-    Any malformedErrorType =
-        Any.newBuilder()
-            .setTypeUrl("type.googleapis.com/google.rpc.ErrorInfo")
-            .setValue(ByteString.copyFromUtf8("This is an invalid message!"))
-            .build();
-    errorDetails =
-        ErrorDetails.builder().setRawErrorMessages(ImmutableList.of(malformedErrorType)).build();
-    ProtocolBufferParsingException exception =
-        assertThrows(
-            ProtocolBufferParsingException.class, () -> errorDetails.unpack(ErrorInfo.class));
-    Truth.assertThat(exception.getMessage())
-        .isEqualTo(
-            String.format(
-                "Failed to unpack %s from raw error messages", ErrorInfo.class.getSimpleName()));
-  }
-
-  @Test
-  public void unpack_shouldReturnDesiredErrorMessageTypeIfItExist() {
-    Truth.assertThat(errorDetails.unpack(ErrorInfo.class)).isEqualTo(ERROR_INFO);
-  }
-
-  @Test
-  public void errorInfo_shouldUnpackErrorInfoProtoMessage() {
-    Truth.assertThat(errorDetails.getErrorInfo()).isEqualTo(ERROR_INFO);
-  }
-
-  @Test
-  public void retryInfo_shouldUnpackRetryInfoProtoMessage() {
-    Truth.assertThat(errorDetails.getRetryInfo()).isEqualTo(RETRY_INFO);
-  }
-
-  @Test
-  public void debugInfo_shouldUnpackDebugInfoProtoMessage() {
-    Truth.assertThat(errorDetails.getDebugInfo()).isEqualTo(DEBUG_INFO);
-  }
-
-  @Test
-  public void quotaFailure_shouldUnpackQuotaFailureProtoMessage() {
-    Truth.assertThat(errorDetails.getQuotaFailure()).isEqualTo(QUOTA_FAILURE);
-  }
-
-  @Test
-  public void preconditionFailure_shouldUnpackPreconditionFailureProtoMessage() {
-    Truth.assertThat(errorDetails.getPreconditionFailure()).isEqualTo(PRECONDITION_FAILURE);
-  }
-
-  @Test
-  public void badRequest_shouldUnpackBadRequestProtoMessage() {
-    Truth.assertThat(errorDetails.getBadRequest()).isEqualTo(BAD_REQUEST);
-  }
-
-  @Test
-  public void requestInfo_shouldUnpackRequestInfoProtoMessage() {
-    Truth.assertThat(errorDetails.getRequestInfo()).isEqualTo(REQUEST_INFO);
-  }
-
-  @Test
-  public void resourceInfo_shouldUnpackResourceInfoProtoMessage() {
-    Truth.assertThat(errorDetails.getResourceInfo()).isEqualTo(RESOURCE_INFO);
-  }
-
-  @Test
-  public void help_shouldUnpackHelpProtoMessage() {
-    Truth.assertThat(errorDetails.getHelp()).isEqualTo(HELP);
-  }
-
-  @Test
-  public void localizedMessage_shouldUnpackLocalizedMessageProtoMessage() {
-    Truth.assertThat(errorDetails.getHelp()).isEqualTo(HELP);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/FirstElementCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/FirstElementCallableTest.java
deleted file mode 100644
index e26ce719e..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/FirstElementCallableTest.java
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCall;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCallable;
-import com.google.common.truth.Truth;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class FirstElementCallableTest {
-  private MockServerStreamingCallable<String, String> upstream;
-  private FirstElementCallable<String, String> callable;
-
-  @Before
-  public void setup() {
-    upstream = new MockServerStreamingCallable<>();
-    callable = new FirstElementCallable<>(upstream);
-  }
-
-  @Test
-  public void testHappyPath() throws InterruptedException, ExecutionException {
-    ApiFuture<String> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(1);
-    call.getController().getObserver().onResponse("response");
-    Truth.assertThat(result.get()).isEqualTo("response");
-
-    Truth.assertThat(call.getController().getObserver()).isNotNull();
-  }
-
-  @Test
-  public void testEarlyTermination() throws Exception {
-    ApiFuture<String> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    // callable should request a single element on start
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(1);
-
-    // Then the user promptly cancels it
-    result.cancel(true);
-
-    // The cancellation should propagate to the inner callable
-    Truth.assertThat(call.getController().isCancelled()).isTrue();
-    // Then we fake a cancellation going the other way (it will be wrapped in StatusRuntimeException
-    // for grpc)
-    call.getController()
-        .getObserver()
-        .onError(new RuntimeException("Some other upstream cancellation notice"));
-
-    Throwable actualError = null;
-    try {
-      result.get(1, TimeUnit.SECONDS);
-    } catch (Throwable e) {
-      actualError = e;
-    }
-
-    // However, that exception will be ignored and will be replaced by a generic
-    // CancellationException
-    Truth.assertThat(actualError).isInstanceOf(CancellationException.class);
-  }
-
-  @Test
-  public void testNoResults() throws Exception {
-    ApiFuture<String> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-
-    call.getController().getObserver().onComplete();
-    Truth.assertThat(result.get()).isNull();
-  }
-
-  @Test
-  public void testErrorAfterResultIsIgnored() throws Exception {
-    ApiFuture<String> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-    call.getController().getObserver().onResponse("response");
-    call.getController()
-        .getObserver()
-        .onError(new RuntimeException("some error that will be ignored"));
-
-    Truth.assertThat(result.get()).isEqualTo("response");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/FixedHeaderProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/FixedHeaderProviderTest.java
deleted file mode 100644
index 8bffbed0e..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/FixedHeaderProviderTest.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertEquals;
-
-import com.google.common.collect.ImmutableMap;
-import java.util.Map;
-import org.junit.Test;
-
-public class FixedHeaderProviderTest {
-  @Test
-  public void testCreateSuccess() {
-    Map<String, String> headers =
-        ImmutableMap.of("User-Agent", "hello1", "Custom-Header", "hello2");
-    FixedHeaderProvider headerProvider = FixedHeaderProvider.create(headers);
-    assertEquals(headers, headerProvider.getHeaders());
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testCreateFail() {
-    Map<String, String> headers = ImmutableMap.of("User-Agent", "hello1", "user-agent", "hello2");
-    FixedHeaderProvider.create(headers);
-  }
-
-  @Test
-  public void testCreateVarargSuccess() {
-    Map<String, String> headers =
-        ImmutableMap.of("User-Agent", "hello1", "Custom-Header", "hello2");
-    FixedHeaderProvider headerProvider =
-        FixedHeaderProvider.create("User-Agent", "hello1", "Custom-Header", "hello2");
-    assertEquals(headers, headerProvider.getHeaders());
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testCreateVarargFail() {
-    FixedHeaderProvider.create("User-Agent", "hello1", "user-agent", "hello2");
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testCreateVarargOddNumberOfParamsFail() {
-    FixedHeaderProvider.create("User-Agent", "hello1", "Custom-Header");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/FixedTransportChannelProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/FixedTransportChannelProviderTest.java
deleted file mode 100644
index 66187657d..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/FixedTransportChannelProviderTest.java
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.oauth2.ComputeEngineCredentials;
-import com.google.common.truth.Truth;
-import java.util.Collections;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class FixedTransportChannelProviderTest {
-  @Test
-  public void testBasic() throws Exception {
-    TransportChannel transportChannel = FakeTransportChannel.create(new FakeChannel());
-    FixedTransportChannelProvider provider = FixedTransportChannelProvider.create(transportChannel);
-
-    Truth.assertThat(provider.shouldAutoClose()).isFalse();
-
-    Truth.assertThat(provider.needsExecutor()).isFalse();
-
-    Exception thrownException = null;
-    try {
-      provider.withExecutor(new ScheduledThreadPoolExecutor(0));
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    Truth.assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    Truth.assertThat(provider.needsHeaders()).isFalse();
-
-    thrownException = null;
-    try {
-      provider.withHeaders(Collections.<String, String>emptyMap());
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    Truth.assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    Truth.assertThat(provider.needsEndpoint()).isFalse();
-
-    thrownException = null;
-    try {
-      provider.withEndpoint("localhost:8080");
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    Truth.assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    Truth.assertThat(provider.needsCredentials()).isFalse();
-
-    thrownException = null;
-    try {
-      provider.withCredentials(ComputeEngineCredentials.create());
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    Truth.assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    Truth.assertThat(provider.acceptsPoolSize()).isFalse();
-
-    thrownException = null;
-    try {
-      provider.withPoolSize(1);
-    } catch (Exception e) {
-      thrownException = e;
-    }
-    Truth.assertThat(thrownException).isInstanceOf(UnsupportedOperationException.class);
-
-    Truth.assertThat(provider.getTransportChannel()).isSameInstanceAs(transportChannel);
-
-    Truth.assertThat(provider.getTransportName())
-        .isEqualTo(FakeTransportChannel.getFakeTransportName());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/FixedWatchdogProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/FixedWatchdogProviderTest.java
deleted file mode 100644
index 9fb965937..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/FixedWatchdogProviderTest.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.ApiClock;
-import java.util.concurrent.ScheduledExecutorService;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class FixedWatchdogProviderTest {
-  @Test
-  public void testNull() {
-    WatchdogProvider provider = FixedWatchdogProvider.create(null);
-    assertThat(provider.getWatchdog()).isNull();
-  }
-
-  @Test
-  public void testSameInstance() {
-    Watchdog watchdog =
-        Watchdog.create(
-            Mockito.mock(ApiClock.class),
-            Duration.ZERO,
-            Mockito.mock(ScheduledExecutorService.class));
-
-    WatchdogProvider provider = FixedWatchdogProvider.create(watchdog);
-    assertThat(provider.getWatchdog()).isSameInstanceAs(watchdog);
-  }
-
-  @Test
-  public void testNoModifications() {
-    Watchdog watchdog =
-        Watchdog.create(
-            Mockito.mock(ApiClock.class),
-            Duration.ZERO,
-            Mockito.mock(ScheduledExecutorService.class));
-    WatchdogProvider provider = FixedWatchdogProvider.create(watchdog);
-
-    assertThat(provider.needsCheckInterval()).isFalse();
-    assertThat(provider.needsClock()).isFalse();
-    assertThat(provider.needsExecutor()).isFalse();
-    assertThat(provider.shouldAutoClose()).isFalse();
-
-    Throwable actualError = null;
-    try {
-      provider.withCheckInterval(Duration.ofSeconds(10));
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(UnsupportedOperationException.class);
-
-    actualError = null;
-    try {
-      provider.withClock(Mockito.mock(ApiClock.class));
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(UnsupportedOperationException.class);
-
-    actualError = null;
-    try {
-      provider.withExecutor(Mockito.mock(ScheduledExecutorService.class));
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(UnsupportedOperationException.class);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/InstantiatingWatchdogProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/InstantiatingWatchdogProviderTest.java
deleted file mode 100644
index 0607dc717..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/InstantiatingWatchdogProviderTest.java
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.ApiClock;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.threeten.bp.Duration;
-
-@RunWith(MockitoJUnitRunner.class)
-public class InstantiatingWatchdogProviderTest {
-  @Mock private ScheduledExecutorService executor;
-  @Mock private ApiClock clock;
-  private Duration checkInterval = Duration.ofSeconds(11);
-
-  @Test
-  public void happyPath() {
-    WatchdogProvider provider = InstantiatingWatchdogProvider.create();
-
-    assertThat(provider.needsExecutor()).isTrue();
-    provider = provider.withExecutor(executor);
-
-    assertThat(provider.needsClock()).isTrue();
-    provider = provider.withClock(clock);
-
-    assertThat(provider.needsCheckInterval()).isTrue();
-    provider = provider.withCheckInterval(checkInterval);
-
-    assertThat(provider.shouldAutoClose()).isTrue();
-
-    Watchdog watchdog = provider.getWatchdog();
-    Mockito.verify(executor)
-        .scheduleAtFixedRate(
-            watchdog, checkInterval.toMillis(), checkInterval.toMillis(), TimeUnit.MILLISECONDS);
-  }
-
-  @Test
-  public void requiresExecutor() {
-    WatchdogProvider provider =
-        InstantiatingWatchdogProvider.create().withCheckInterval(checkInterval).withClock(clock);
-
-    Throwable actualError = null;
-    try {
-      provider.getWatchdog();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(IllegalStateException.class);
-  }
-
-  @Test
-  public void requiresCheckInterval() {
-    WatchdogProvider provider =
-        InstantiatingWatchdogProvider.create().withExecutor(executor).withClock(clock);
-
-    Throwable actualError = null;
-    try {
-      provider.getWatchdog();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(IllegalStateException.class);
-  }
-
-  @Test
-  public void requiresClock() {
-    WatchdogProvider provider =
-        InstantiatingWatchdogProvider.create()
-            .withExecutor(executor)
-            .withCheckInterval(checkInterval);
-
-    Throwable actualError = null;
-    try {
-      provider.getWatchdog();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    assertThat(actualError).isInstanceOf(IllegalStateException.class);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/LatchCountDownScheduler.java b/gax/src/test/java/com/google/api/gax/rpc/LatchCountDownScheduler.java
deleted file mode 100644
index 492dbb7d7..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/LatchCountDownScheduler.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyLong;
-import static org.mockito.Mockito.when;
-
-import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import java.util.concurrent.TimeUnit;
-import org.mockito.Mockito;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
-
-public abstract class LatchCountDownScheduler implements ScheduledExecutorService {
-  public static LatchCountDownScheduler get(
-      final CountDownLatch latch,
-      final long delayBeforeCountDown,
-      final long extraDelayAfterCountDown) {
-    LatchCountDownScheduler mock = Mockito.mock(LatchCountDownScheduler.class);
-
-    // mock class fields:
-    final ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
-
-    // mock class methods:
-    // ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);
-    when(mock.schedule(any(Runnable.class), anyLong(), any(TimeUnit.class)))
-        .then(
-            new Answer<ScheduledFuture<?>>() {
-              @Override
-              public ScheduledFuture<?> answer(InvocationOnMock invocation) throws Throwable {
-                Object[] args = invocation.getArguments();
-                Long delay = (Long) args[1];
-                TimeUnit timeUnit = (TimeUnit) args[2];
-                delay += timeUnit.convert(extraDelayAfterCountDown, TimeUnit.MILLISECONDS);
-                latch.countDown();
-                if (delayBeforeCountDown > 0L) {
-                  Thread.sleep(delayBeforeCountDown);
-                }
-                return executor.schedule((Runnable) args[0], delay, timeUnit);
-              }
-            });
-    // List<Runnable> shutdownNow()
-    when(mock.shutdownNow())
-        .then(
-            new Answer<List<Runnable>>() {
-              @Override
-              public List<Runnable> answer(InvocationOnMock invocation) throws Throwable {
-                return executor.shutdownNow();
-              }
-            });
-
-    return mock;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/OperationCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/OperationCallSettingsTest.java
deleted file mode 100644
index f3f9f603b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/OperationCallSettingsTest.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.TimedRetryAlgorithm;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.truth.Truth;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class OperationCallSettingsTest {
-
-  @Test
-  public void testEmptyBuilder() {
-    OperationCallSettings.Builder builder = OperationCallSettings.newBuilder();
-
-    Truth.assertThat(builder.getResponseTransformer()).isNull();
-    Truth.assertThat(builder.getMetadataTransformer()).isNull();
-    Truth.assertThat(builder.getInitialCallSettings()).isNull();
-    Truth.assertThat(builder.getPollingAlgorithm()).isNull();
-  }
-
-  @Test
-  public void testBuilder() {
-    OperationCallSettings.Builder<Integer, String, Long> builder =
-        OperationCallSettings.newBuilder();
-
-    UnaryCallSettings<Integer, OperationSnapshot> initialCallSettings =
-        UnaryCallSettings.<Integer, OperationSnapshot>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(Code.UNAVAILABLE)
-            .build();
-    TimedRetryAlgorithm pollingAlgorithm = Mockito.mock(TimedRetryAlgorithm.class);
-    ResponseTransformer responseTransformer = new ResponseTransformer();
-    MetadataTransformer metadataTransformer = new MetadataTransformer();
-
-    builder.setPollingAlgorithm(pollingAlgorithm);
-    builder.setResponseTransformer(responseTransformer);
-    builder.setMetadataTransformer(metadataTransformer);
-    builder.setInitialCallSettings(initialCallSettings);
-
-    Truth.assertThat(builder.getInitialCallSettings()).isSameInstanceAs(initialCallSettings);
-
-    OperationCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getPollingAlgorithm()).isSameInstanceAs(pollingAlgorithm);
-    Truth.assertThat(settings.getResponseTransformer()).isSameInstanceAs(responseTransformer);
-    Truth.assertThat(settings.getMetadataTransformer()).isSameInstanceAs(metadataTransformer);
-    Truth.assertThat(settings.getInitialCallSettings()).isNotNull();
-    Truth.assertThat(settings.getInitialCallSettings().getRetryableCodes().size()).isEqualTo(1);
-  }
-
-  @Test
-  public void testBuilderFromSettings() throws Exception {
-    OperationCallSettings.Builder<Integer, String, Long> builder =
-        OperationCallSettings.newBuilder();
-
-    UnaryCallSettings<Integer, OperationSnapshot> initialCallSettings =
-        UnaryCallSettings.<Integer, OperationSnapshot>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(Code.UNAVAILABLE)
-            .build();
-    TimedRetryAlgorithm pollingAlgorithm = Mockito.mock(TimedRetryAlgorithm.class);
-    ResponseTransformer responseTransformer = new ResponseTransformer();
-    MetadataTransformer metadataTransformer = new MetadataTransformer();
-
-    builder.setPollingAlgorithm(pollingAlgorithm);
-    builder.setResponseTransformer(responseTransformer);
-    builder.setMetadataTransformer(metadataTransformer);
-    builder.setInitialCallSettings(initialCallSettings);
-
-    Truth.assertThat(builder.getInitialCallSettings()).isSameInstanceAs(initialCallSettings);
-
-    OperationCallSettings settings = builder.build();
-    OperationCallSettings.Builder newBuilder = settings.toBuilder();
-
-    Truth.assertThat(newBuilder.getPollingAlgorithm()).isSameInstanceAs(pollingAlgorithm);
-    Truth.assertThat(newBuilder.getResponseTransformer()).isSameInstanceAs(responseTransformer);
-    Truth.assertThat(newBuilder.getMetadataTransformer()).isSameInstanceAs(metadataTransformer);
-    Truth.assertThat(newBuilder.getInitialCallSettings()).isNotNull();
-    Truth.assertThat(newBuilder.getInitialCallSettings().getRetryableCodes().size()).isEqualTo(1);
-  }
-
-  private static class ResponseTransformer implements ApiFunction<OperationSnapshot, String> {
-    @Override
-    public String apply(OperationSnapshot operationSnapshot) {
-      return (String) operationSnapshot.getResponse();
-    }
-  }
-
-  private static class MetadataTransformer implements ApiFunction<OperationSnapshot, Long> {
-    @Override
-    public Long apply(OperationSnapshot operationSnapshot) {
-      return (Long) operationSnapshot.getMetadata();
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/OperationCallableImplTest.java b/gax/src/test/java/com/google/api/gax/rpc/OperationCallableImplTest.java
deleted file mode 100644
index 5779f72f7..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/OperationCallableImplTest.java
+++ /dev/null
@@ -1,1306 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.ListenableFutureToApiFuture;
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.core.RecordingScheduler;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.longrunning.OperationFutureImpl;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.longrunning.OperationTimedPollAlgorithm;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeOperationApi.OperationStashCallable;
-import com.google.api.gax.rpc.testing.FakeOperationSnapshot;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.Credentials;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import com.google.common.util.concurrent.Futures;
-import java.awt.Color;
-import java.io.IOException;
-import java.util.Currency;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import java.util.concurrent.locks.LockSupport;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class OperationCallableImplTest {
-
-  private static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(2L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(2L))
-          .setInitialRpcTimeout(Duration.ofMillis(2L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(2L))
-          .setTotalTimeout(Duration.ofMillis(10L))
-          .build();
-
-  private static final RetrySettings FAST_RECHECKING_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(1L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(1L))
-          .setInitialRpcTimeout(
-              Duration.ZERO) // supposed to be ignored, but are not actually, so we set to zero
-          .setMaxAttempts(0)
-          .setJittered(false)
-          .setRpcTimeoutMultiplier(
-              1) // supposed to be ignored, but are not actually, so we set to one
-          .setMaxRpcTimeout(
-              Duration.ZERO) // supposed to be ignored, but are not actually, so we set to zero
-          .setTotalTimeout(Duration.ofMillis(5L))
-          .build();
-
-  private FakeChannel initialChannel;
-  private TransportChannel pollTransportChannel;
-  private RecordingScheduler executor;
-  private ClientContext initialContext;
-  private OperationCallSettings<Integer, Color, Currency> callSettings;
-
-  private FakeApiClock clock;
-  private OperationTimedPollAlgorithm pollingAlgorithm;
-
-  @Before
-  public void setUp() throws IOException {
-    initialChannel = mock(FakeChannel.class);
-    pollTransportChannel = mock(TransportChannel.class);
-    TransportChannelProvider operationsChannelProvider = mock(TransportChannelProvider.class);
-    when(operationsChannelProvider.getTransportChannel()).thenReturn(pollTransportChannel);
-
-    clock = new FakeApiClock(0L);
-    executor = RecordingScheduler.create(clock);
-    pollingAlgorithm = OperationTimedPollAlgorithm.create(FAST_RECHECKING_SETTINGS, clock);
-
-    UnaryCallSettings<Integer, OperationSnapshot> initialCallSettings =
-        UnaryCallSettings.<Integer, OperationSnapshot>newUnaryCallSettingsBuilder()
-            .setRetrySettings(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(1).build())
-            .build();
-
-    callSettings =
-        OperationCallSettings.<Integer, Color, Currency>newBuilder()
-            .setInitialCallSettings(initialCallSettings)
-            .setResponseTransformer(new ResponseTransformer())
-            .setMetadataTransformer(new MetadataTransformer())
-            .setPollingAlgorithm(pollingAlgorithm)
-            .build();
-
-    initialContext = getClientContext(initialChannel, executor);
-  }
-
-  private static class ResponseTransformer implements ApiFunction<OperationSnapshot, Color> {
-    @Override
-    public Color apply(OperationSnapshot operationSnapshot) {
-      if (!operationSnapshot.getErrorCode().getCode().equals(StatusCode.Code.OK)) {
-        throw ApiExceptionFactory.createException(
-            "Operation with name \""
-                + operationSnapshot.getName()
-                + "\" failed with status = "
-                + operationSnapshot.getErrorCode()
-                + " and message = "
-                + operationSnapshot.getErrorMessage(),
-            null,
-            operationSnapshot.getErrorCode(),
-            false);
-      }
-      if (operationSnapshot.getResponse() == null) {
-        return null;
-      }
-      if (!(operationSnapshot.getResponse() instanceof Color)) {
-        String errorMessage =
-            "type mismatch: expected "
-                + Color.class.getName()
-                + ", found "
-                + operationSnapshot.getResponse().getClass().getName();
-        throw new ApiException(errorMessage, null, FakeStatusCode.of(StatusCode.Code.OK), false);
-      } else {
-        return (Color) operationSnapshot.getResponse();
-      }
-    }
-  }
-
-  private static class MetadataTransformer implements ApiFunction<OperationSnapshot, Currency> {
-    @Override
-    public Currency apply(OperationSnapshot operationSnapshot) {
-      if (operationSnapshot.getMetadata() == null) {
-        return null;
-      }
-      if (!(operationSnapshot.getMetadata() instanceof Currency)) {
-        String errorMessage =
-            "type mismatch: expected "
-                + Currency.class.getName()
-                + ", found "
-                + operationSnapshot.getMetadata().getClass().getName();
-        throw new ApiException(errorMessage, null, FakeStatusCode.of(StatusCode.Code.OK), false);
-      } else {
-        return (Currency) operationSnapshot.getMetadata();
-      }
-    }
-  }
-
-  @After
-  public void tearDown() {
-    executor.shutdown();
-  }
-
-  @Test
-  public void testCall() {
-    Color resp = getColor(1.0f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation("testCall", resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    Color response = callable.call(2, FakeCallContext.createDefault());
-    Truth.assertThat(response).isEqualTo(resp);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testResumeFutureCall() throws Exception {
-    String opName = "testResumeFutureCall";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    ClientContext mockContext = getClientContext(new FakeChannel(), executor);
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            getUnexpectedStartCallable(), callSettings, mockContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future = callable.resumeFutureCall(opName);
-
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testCancelOperation() throws Exception {
-    String opName = "testCancelOperation";
-    LongRunningClient longRunningClient = mockCancelOperation(StatusCode.Code.OK);
-
-    ClientContext mockContext = getClientContext(new FakeChannel(), executor);
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            getUnexpectedStartCallable(), callSettings, mockContext, longRunningClient);
-
-    ApiFuture<Void> future = callable.cancel(opName);
-    assertThat(future.get()).isNull();
-  }
-
-  @Test
-  public void testFutureCallInitialDone() throws Exception {
-    String opName = "testFutureCallInitialDone";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialError() throws Exception {
-    String opName = "testFutureCallInitialError";
-    Color resp = getColor(1.0f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.UNAVAILABLE, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureFailMetaFail(future, null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE));
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialDoneWithError() throws Exception {
-    String opName = "testFutureCallInitialDoneWithError";
-    StatusCode errorCode = FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation =
-        getOperation(opName, null, errorCode, meta, true, "Already exists error");
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    String errorMessage =
-        "Operation with name \""
-            + opName
-            + "\" failed with status = "
-            + errorCode
-            + " and message = "
-            + "Already exists error";
-    assertFutureFailMetaSuccess(
-        future, meta, FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS), errorMessage);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialDoneWrongType() throws Exception {
-    String opName = "testFutureCallInitialDoneWrongType";
-    Currency resp = Currency.getInstance("USD");
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureFailMetaSuccess(
-        future,
-        meta,
-        FakeStatusCode.of(StatusCode.Code.OK),
-        "type mismatch: expected java.awt.Color, found java.util.Currency");
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialDoneMetaWrongType() throws Exception {
-    String opName = "testFutureCallInitialDoneMetaWrongType";
-    Color resp = getColor(1.0f);
-    Color meta = getColor(1.0f);
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureSuccessMetaFail(future, resp, FakeStatusCode.of(StatusCode.Code.OK));
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialCancel() throws Exception {
-    String opName = "testFutureCallInitialCancel";
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation = getOperation(opName, null, null, null, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    OperationCallableImpl<Integer, Color, Currency> callableImpl =
-        Callables.longRunningOperationImpl(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFutureImpl<Color, Currency> future =
-        callableImpl.futureCall(
-            new ListenableFutureToApiFuture<>(
-                Futures.<OperationSnapshot>immediateCancelledFuture()),
-            FakeCallContext.createDefault());
-
-    Exception exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-
-    assertThat(exception).isNotNull();
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isTrue();
-    assertThat(future.getInitialFuture().isDone()).isTrue();
-    assertThat(future.getInitialFuture().isCancelled()).isTrue();
-
-    assertFutureCancelMetaCancel(future);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallInitialOperationUnexpectedFail() throws Exception {
-    String opName = "testFutureCallInitialOperationUnexpectedFail";
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation = getOperation(opName, null, null, null, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    OperationCallableImpl<Integer, Color, Currency> callableImpl =
-        Callables.longRunningOperationImpl(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    RuntimeException thrownException = new RuntimeException();
-
-    ApiFuture<OperationSnapshot> initialFuture = ApiFutures.immediateFailedFuture(thrownException);
-    OperationFuture<Color, Currency> future =
-        callableImpl.futureCall(initialFuture, FakeCallContext.createDefault());
-
-    assertFutureFailMetaFail(future, RuntimeException.class, null);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallPollDoneOnFirst() throws Exception {
-    String opName = "testFutureCallPollDoneOnFirst";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallPollDoneOnSecond() throws Exception {
-    String opName = "testFutureCallPollDoneOnSecond";
-    Color resp = getColor(0.5f);
-    Currency meta1 = Currency.getInstance("UAH");
-    Currency meta2 = Currency.getInstance("USD");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation1 = getOperation(opName, null, null, meta1, false);
-    OperationSnapshot resultOperation2 = getOperation(opName, resp, null, meta2, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient =
-        mockGetOperation(StatusCode.Code.OK, resultOperation1, resultOperation2);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta2);
-    assertThat(executor.getIterationsCount()).isEqualTo(1);
-  }
-
-  @Test
-  public void testFutureCallPollRPCTimeout() throws Exception {
-    String opName = "testFutureCallPollRPCTimeout";
-    pollingAlgorithm =
-        OperationTimedPollAlgorithm.create(
-            FAST_RECHECKING_SETTINGS
-                .toBuilder()
-                // Update the polling algorithm to set per-RPC timeouts instead of the default zero.
-                //
-                // This is non-standard, as these fields have been documented as "should be ignored"
-                // for LRO polling. They are not actually ignored in code, so they changing them
-                // here has an actual affect. This test verifies that they work as such, but in
-                // practice generated clients set the RPC timeouts to 0 to be ignored.
-                .setInitialRpcTimeout(Duration.ofMillis(100))
-                .setMaxRpcTimeout(Duration.ofSeconds(1))
-                .setRpcTimeoutMultiplier(2)
-                .setTotalTimeout(Duration.ofSeconds(5L))
-                .build(),
-            clock);
-    callSettings = callSettings.toBuilder().setPollingAlgorithm(pollingAlgorithm).build();
-
-    Color resp = getColor(0.5f);
-    Currency meta1 = Currency.getInstance("UAH");
-    Currency meta2 = Currency.getInstance("USD");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation1 = getOperation(opName, null, null, meta1, false);
-    OperationSnapshot resultOperation2 = getOperation(opName, null, null, meta1, false);
-    OperationSnapshot resultOperation3 = getOperation(opName, resp, null, meta2, true);
-
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-
-    LongRunningClient longRunningClient = Mockito.mock(LongRunningClient.class);
-    @SuppressWarnings("unchecked")
-    UnaryCallable<String, OperationSnapshot> getOpCallable = Mockito.mock(UnaryCallable.class);
-    ArgumentCaptor<ApiCallContext> callContextCaptor =
-        ArgumentCaptor.forClass(ApiCallContext.class);
-    Mockito.when(longRunningClient.getOperationCallable()).thenReturn(getOpCallable);
-
-    Mockito.when(getOpCallable.futureCall(Mockito.<String>any(), callContextCaptor.capture()))
-        .thenReturn(ApiFutures.immediateFuture(resultOperation1))
-        .thenReturn(ApiFutures.immediateFuture(resultOperation2))
-        .thenReturn(ApiFutures.immediateFuture(resultOperation3));
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    callable.futureCall(2, FakeCallContext.createDefault()).get(10, TimeUnit.SECONDS);
-
-    List<Duration> actualTimeouts = Lists.newArrayList();
-
-    for (ApiCallContext callContext : callContextCaptor.getAllValues()) {
-      actualTimeouts.add(callContext.getTimeout());
-    }
-
-    List<Duration> expectedTimeouts =
-        Lists.newArrayList(Duration.ofMillis(100), Duration.ofMillis(200), Duration.ofMillis(400));
-    assertThat(actualTimeouts).isEqualTo(expectedTimeouts);
-  }
-
-  @Test
-  public void testFutureCallContextPropagation() throws Exception {
-    String opName = "testFutureCallContextPropagation";
-
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("USD");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, true);
-
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-
-    LongRunningClient longRunningClient = Mockito.mock(LongRunningClient.class);
-    @SuppressWarnings("unchecked")
-    UnaryCallable<String, OperationSnapshot> getOpCallable = Mockito.mock(UnaryCallable.class);
-    ArgumentCaptor<ApiCallContext> callContextCaptor =
-        ArgumentCaptor.forClass(ApiCallContext.class);
-    Mockito.when(longRunningClient.getOperationCallable()).thenReturn(getOpCallable);
-
-    Mockito.when(getOpCallable.futureCall(Mockito.<String>any(), callContextCaptor.capture()))
-        .thenReturn(ApiFutures.immediateFuture(resultOperation));
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    ApiCallContext callContext = FakeCallContext.createDefault().withTimeout(Duration.ofMillis(10));
-
-    callable.futureCall(2, callContext).get(10, TimeUnit.SECONDS);
-
-    assertThat(callContextCaptor.getValue().getTimeout()).isEqualTo(Duration.ofMillis(10));
-  }
-
-  @Test
-  public void testFutureCallPollDoneOnMany() throws Exception {
-    final int iterationsCount = 1000;
-    String opName = "testFutureCallPollDoneOnMany";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-
-    OperationSnapshot[] pollOperations = new OperationSnapshot[iterationsCount];
-    for (int i = 0; i < iterationsCount - 1; i++) {
-      pollOperations[i] = getOperation(opName, null, null, meta, false);
-    }
-    pollOperations[iterationsCount - 1] = getOperation(opName, resp, null, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, pollOperations);
-
-    pollingAlgorithm =
-        OperationTimedPollAlgorithm.create(
-            FAST_RECHECKING_SETTINGS
-                .toBuilder()
-                .setTotalTimeout(Duration.ofMillis(iterationsCount))
-                .build(),
-            clock);
-    callSettings = callSettings.toBuilder().setPollingAlgorithm(pollingAlgorithm).build();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    Truth.assertThat(future.get(5, TimeUnit.SECONDS)).isEqualTo(resp);
-    assertFutureSuccessMetaSuccess(opName, future, resp, meta);
-
-    assertThat(executor.getIterationsCount()).isEqualTo(iterationsCount - 1);
-  }
-
-  @Test
-  public void testFutureCallPollError() throws Exception {
-    String opName = "testFutureCallPollError";
-    Currency meta = Currency.getInstance("UAH");
-    Color resp = getColor(1.0f);
-    OperationSnapshot initialOperation = getOperation(opName, resp, null, meta, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    OperationSnapshot resultOperation = getOperation(opName, resp, null, meta, false);
-    LongRunningClient longRunningClient =
-        mockGetOperation(StatusCode.Code.ALREADY_EXISTS, resultOperation);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureFailMetaFail(future, null, FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS));
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallPollDoneWithError() throws Exception {
-    String opName = "testFutureCallPollDoneWithError";
-    Currency meta = Currency.getInstance("UAH");
-    Color resp = getColor(1.0f);
-    OperationSnapshot initialOperation =
-        getOperation(opName, resp, null, meta, false, "Already exists error");
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-
-    StatusCode errorCode = FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS);
-    OperationSnapshot resultOperation =
-        getOperation(opName, null, errorCode, meta, true, "Already exists error");
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    String errorMessage =
-        "Operation with name \""
-            + opName
-            + "\" failed with status = "
-            + errorCode
-            + " and message = "
-            + "Already exists error";
-    assertFutureFailMetaSuccess(
-        future, meta, FakeStatusCode.of(StatusCode.Code.ALREADY_EXISTS), errorMessage);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFutureCallPollCancelOnTimeoutExceeded() throws Exception {
-    String opName = "testFutureCallPollCancelOnPollingTimeoutExceeded";
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation = getOperation(opName, null, null, null, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, resultOperation);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureCancelMetaCancel(future);
-    assertThat(executor.getIterationsCount()).isEqualTo(5);
-  }
-
-  @Test
-  public void testFutureCallPollCancelOnLongTimeoutExceeded() throws Exception {
-    final int iterationsCount = 1000;
-    String opName = "testFutureCallPollCancelOnLongTimeoutExceeded";
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-
-    OperationSnapshot[] pollOperations = new OperationSnapshot[iterationsCount];
-    for (int i = 0; i < iterationsCount; i++) {
-      pollOperations[i] = getOperation(opName, null, null, null, false);
-    }
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, pollOperations);
-
-    pollingAlgorithm =
-        OperationTimedPollAlgorithm.create(
-            FAST_RECHECKING_SETTINGS.toBuilder().setTotalTimeout(Duration.ofMillis(1000L)).build(),
-            clock);
-    callSettings = callSettings.toBuilder().setPollingAlgorithm(pollingAlgorithm).build();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    assertFutureCancelMetaCancel(future);
-    assertThat(executor.getIterationsCount()).isEqualTo(iterationsCount);
-  }
-
-  @Test
-  public void testFutureCancelImmediately() throws Exception {
-    int iterationsCount = 3;
-    String opName = "testCancelImmediately";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, null, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-
-    OperationSnapshot[] pollOperations = new OperationSnapshot[iterationsCount];
-    for (int i = 0; i < iterationsCount; i++) {
-      pollOperations[i] = getOperation(opName, null, null, null, false);
-    }
-    pollOperations[iterationsCount - 1] = getOperation(opName, resp, null, meta, true);
-
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, pollOperations);
-
-    CountDownLatch retryScheduledLatch = new CountDownLatch(1);
-    LatchCountDownScheduler scheduler = LatchCountDownScheduler.get(retryScheduledLatch, 0L, 20L);
-
-    ClientContext schedulerContext = getClientContext(initialChannel, scheduler);
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, schedulerContext, longRunningClient);
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    while (!future.cancel(true) && !future.isDone()) {
-      LockSupport.parkNanos(1000L);
-    }
-
-    assertFutureCancelMetaCancel(future);
-    scheduler.shutdownNow();
-  }
-
-  @Test
-  public void testFutureCancelInTheMiddle() throws Exception {
-    int iterationsCount = 1000;
-    String opName = "testCancelInTheMiddle";
-    Color resp = getColor(0.5f);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, null, null, null, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-
-    OperationSnapshot[] pollOperations = new OperationSnapshot[iterationsCount];
-    for (int i = 0; i < iterationsCount - 1; i++) {
-      pollOperations[i] = getOperation(opName, null, null, null, false);
-    }
-    pollOperations[iterationsCount - 1] = getOperation(opName, resp, null, meta, true);
-    LongRunningClient longRunningClient = mockGetOperation(StatusCode.Code.OK, pollOperations);
-
-    CountDownLatch retryScheduledLatch = new CountDownLatch(10);
-    LatchCountDownScheduler scheduler = LatchCountDownScheduler.get(retryScheduledLatch, 0L, 1L);
-
-    ClientContext schedulerContext = getClientContext(initialChannel, scheduler);
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, schedulerContext, longRunningClient);
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    CancellationHelpers.cancelInThreadAfterLatchCountDown(future, retryScheduledLatch);
-
-    assertFutureCancelMetaCancel(future);
-  }
-
-  @Test
-  public void testInitialServerSideCancel() throws Exception {
-    String opName = "testInitialServerSideCancel";
-    StatusCode errorCode = FakeStatusCode.of(StatusCode.Code.CANCELLED);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot resultOperation = getOperation(opName, null, errorCode, meta, true);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, resultOperation);
-    LongRunningClient longRunningClient = new UnsupportedOperationApi();
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    String errorMessage =
-        "Operation with name \""
-            + opName
-            + "\" failed with status = "
-            + errorCode
-            + " and message = "
-            + "null";
-    assertFutureFailMetaSuccess(
-        future, meta, FakeStatusCode.of(StatusCode.Code.CANCELLED), errorMessage);
-    assertThat(executor.getIterationsCount()).isEqualTo(0);
-  }
-
-  @Test
-  public void testPollServerSideCancel() throws Exception {
-    String opName = "testPollServerSideCancel";
-    StatusCode errorCode = FakeStatusCode.of(StatusCode.Code.CANCELLED);
-    Currency meta = Currency.getInstance("UAH");
-    OperationSnapshot initialOperation = getOperation(opName, null, null, meta, false);
-    UnaryCallable<Integer, OperationSnapshot> initialCallable =
-        mockGetOpSnapshotCallable(StatusCode.Code.OK, initialOperation);
-    OperationSnapshot resultOperation1 = getOperation(opName, null, null, null, false);
-    OperationSnapshot resultOperation2 = getOperation(opName, null, errorCode, meta, true);
-    LongRunningClient longRunningClient =
-        mockGetOperation(StatusCode.Code.OK, resultOperation1, resultOperation2);
-
-    OperationCallable<Integer, Color, Currency> callable =
-        FakeCallableFactory.createOperationCallable(
-            initialCallable, callSettings, initialContext, longRunningClient);
-
-    OperationFuture<Color, Currency> future =
-        callable.futureCall(2, FakeCallContext.createDefault());
-
-    String errorMessage =
-        "Operation with name \""
-            + opName
-            + "\" failed with status = "
-            + errorCode
-            + " and message = "
-            + "null";
-    assertFutureFailMetaSuccess(
-        future, meta, FakeStatusCode.of(StatusCode.Code.CANCELLED), errorMessage);
-    assertThat(executor.getIterationsCount()).isEqualTo(1);
-  }
-
-  @Test
-  public void call() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-
-    String response = callable.call(1);
-    Truth.assertThat(response).isEqualTo("1");
-    Truth.assertThat(stashCallable.getContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void callWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-
-    String response = callable.call(2, context);
-    Truth.assertThat(response).isEqualTo("2");
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void callResume() throws Exception {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-
-    OperationFuture<String, Long> operationFuture = callable.futureCall(45);
-
-    String response = callable.resumeFutureCall(operationFuture.getName()).get();
-    Truth.assertThat(response).isEqualTo("45");
-    Truth.assertThat(stashCallable.getResumeContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void callResumeWithContext() throws Exception {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-
-    OperationFuture<String, Long> operationFuture = callable.futureCall(45);
-
-    String response = callable.resumeFutureCall(operationFuture.getName(), context).get();
-    Truth.assertThat(response).isEqualTo("45");
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getResumeContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void callCancel() throws Exception {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-
-    OperationFuture<String, Long> operationFuture = callable.futureCall(45);
-
-    callable.cancel(operationFuture.getName()).get();
-    Truth.assertThat(stashCallable.wasCancelCalled()).isTrue();
-    Truth.assertThat(stashCallable.getCancelContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void callCancelWithContext() throws Exception {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    OperationStashCallable stashCallable = new OperationStashCallable();
-    OperationCallable<Integer, String, Long> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-
-    OperationFuture<String, Long> operationFuture = callable.futureCall(45);
-
-    callable.cancel(operationFuture.getName(), context).get();
-    Truth.assertThat(stashCallable.wasCancelCalled()).isTrue();
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getCancelContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  private void assertFutureSuccessMetaSuccess(
-      String opName, OperationFuture<Color, Currency> future, Color resp, Currency meta)
-      throws InterruptedException, ExecutionException, TimeoutException {
-    assertThat(future.getName()).isEqualTo(opName);
-    Truth.assertThat(future.get(3, TimeUnit.SECONDS)).isEqualTo(resp);
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isFalse();
-    Truth.assertThat(future.get()).isEqualTo(resp);
-
-    Truth.assertThat(future.peekMetadata().get()).isEqualTo(meta);
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isFalse();
-
-    Truth.assertThat(future.getMetadata().get()).isEqualTo(meta);
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isFalse();
-  }
-
-  private void assertFutureFailMetaFail(
-      OperationFuture<Color, Currency> future,
-      Class<? extends Exception> exceptionClass,
-      FakeStatusCode statusCode)
-      throws TimeoutException, InterruptedException {
-    Exception exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-
-    assertThat(exception).isNotNull();
-    if (statusCode != null) {
-      assertExceptionMatchesCode(statusCode, exception.getCause());
-      ApiException cause = (ApiException) exception.getCause();
-      assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    } else {
-      assertThat(exception.getCause().getClass()).isEqualTo(exceptionClass);
-    }
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isFalse();
-
-    try {
-      future.peekMetadata().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-    assertThat(exception).isNotNull();
-    if (statusCode != null) {
-      assertExceptionMatchesCode(statusCode, exception.getCause());
-      ApiException cause = (ApiException) exception.getCause();
-      assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    } else {
-      assertThat(exception.getCause().getClass()).isEqualTo(exceptionClass);
-    }
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isFalse();
-
-    try {
-      future.getMetadata().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-    assertThat(exception).isNotNull();
-    if (statusCode != null) {
-      assertExceptionMatchesCode(statusCode, exception.getCause());
-      ApiException cause = (ApiException) exception.getCause();
-      assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    } else {
-      assertThat(exception.getCause().getClass()).isEqualTo(exceptionClass);
-    }
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isFalse();
-  }
-
-  private void assertFutureFailMetaSuccess(
-      OperationFuture<Color, Currency> future,
-      Currency meta,
-      FakeStatusCode statusCode,
-      String errorMessage)
-      throws TimeoutException, InterruptedException, ExecutionException {
-    Exception exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-
-    assertThat(exception).isNotNull();
-    assertExceptionMatchesCode(statusCode, exception.getCause());
-    ApiException cause = (ApiException) exception.getCause();
-    assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    assertThat(cause.getMessage()).isEqualTo(errorMessage);
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isFalse();
-
-    Truth.assertThat(future.peekMetadata().get()).isEqualTo(meta);
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isFalse();
-
-    Truth.assertThat(future.getMetadata().get()).isEqualTo(meta);
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isFalse();
-  }
-
-  private void assertFutureSuccessMetaFail(
-      OperationFuture<Color, Currency> future, Color resp, FakeStatusCode statusCode)
-      throws TimeoutException, InterruptedException, ExecutionException {
-    Exception exception = null;
-    Truth.assertThat(future.get(3, TimeUnit.SECONDS)).isEqualTo(resp);
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isFalse();
-    Truth.assertThat(future.get()).isEqualTo(resp);
-
-    try {
-      future.peekMetadata().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(exception).isNotNull();
-    assertExceptionMatchesCode(statusCode, exception.getCause());
-    ApiException cause = (ApiException) exception.getCause();
-    assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isFalse();
-
-    try {
-      future.getMetadata().get(3, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      exception = e;
-    }
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(exception).isNotNull();
-    assertExceptionMatchesCode(statusCode, exception.getCause());
-    cause = (ApiException) exception.getCause();
-    assertThat(cause.getStatusCode()).isEqualTo(statusCode);
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isFalse();
-  }
-
-  private void assertFutureCancelMetaCancel(OperationFuture<Color, Currency> future)
-      throws InterruptedException, ExecutionException, TimeoutException {
-    Exception exception = null;
-    try {
-      future.get(3, TimeUnit.SECONDS);
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertThat(exception).isNotNull();
-    assertThat(future.isDone()).isTrue();
-    assertThat(future.isCancelled()).isTrue();
-
-    try {
-      future.peekMetadata().get();
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertThat(future.peekMetadata()).isSameInstanceAs(future.peekMetadata());
-    assertThat(exception).isNotNull();
-    assertThat(future.peekMetadata().isDone()).isTrue();
-    assertThat(future.peekMetadata().isCancelled()).isTrue();
-
-    try {
-      future.getMetadata().get();
-    } catch (CancellationException e) {
-      exception = e;
-    }
-    assertThat(future.getMetadata()).isSameInstanceAs(future.getMetadata());
-    assertThat(exception).isNotNull();
-    assertThat(future.getMetadata().isDone()).isTrue();
-    assertThat(future.getMetadata().isCancelled()).isTrue();
-  }
-
-  private Color getColor(float blueValue) {
-    return new Color(0.0f, 0.0f, blueValue);
-  }
-
-  private ClientContext getClientContext(FakeChannel channel, ScheduledExecutorService executor) {
-    return ClientContext.newBuilder()
-        .setTransportChannel(FakeTransportChannel.create(channel))
-        .setExecutor(executor)
-        .setDefaultCallContext(FakeCallContext.createDefault())
-        .build();
-  }
-
-  private OperationSnapshot getOperation(
-      String name,
-      Object response,
-      StatusCode errorCode,
-      Object metadata,
-      boolean done,
-      String errorMessage) {
-    FakeOperationSnapshot.Builder builder =
-        FakeOperationSnapshot.newBuilder().setName(name).setDone(done);
-    if (response != null) {
-      builder.setResponse(response);
-    }
-    if (errorCode != null) {
-      builder.setErrorCode(errorCode);
-    } else {
-      builder.setErrorCode(FakeStatusCode.of(StatusCode.Code.OK));
-    }
-    if (metadata != null) {
-      builder.setMetadata(metadata);
-    }
-    if (errorMessage != null) {
-      builder.setErrorMessage(errorMessage);
-    }
-    return builder.build();
-  }
-
-  private OperationSnapshot getOperation(
-      String name, Object response, StatusCode errorCode, Object metadata, boolean done) {
-    return getOperation(name, response, errorCode, metadata, done, null);
-  }
-
-  private <RequestT> UnaryCallable<RequestT, OperationSnapshot> mockGetOpSnapshotCallable(
-      final StatusCode.Code returnStatusCode, final OperationSnapshot... results) {
-    return new UnaryCallable<RequestT, OperationSnapshot>() {
-      private int index = 0;
-
-      @Override
-      public ApiFuture<OperationSnapshot> futureCall(RequestT request, ApiCallContext context) {
-        FakeCallContext fakeCallContext = (FakeCallContext) context;
-        if (fakeCallContext != null
-            && fakeCallContext.getTimeout() != null
-            && fakeCallContext.getTimeout().isZero()) {
-          throw new DeadlineExceededException(
-              "Invalid timeout of 0 s",
-              null,
-              FakeStatusCode.of(StatusCode.Code.DEADLINE_EXCEEDED),
-              true);
-        }
-        OperationSnapshot response = results[index];
-        if (index < results.length - 1) {
-          index += 1;
-        }
-        return newFuture(returnStatusCode, response);
-      }
-    };
-  }
-
-  private UnaryCallable<Integer, OperationSnapshot> getUnexpectedStartCallable() {
-    return new UnaryCallable<Integer, OperationSnapshot>() {
-      @Override
-      public ApiFuture<OperationSnapshot> futureCall(Integer request, ApiCallContext context) {
-        return ApiFutures.immediateFailedFuture(
-            new UnsupportedOperationException("Unexpected call to start operation"));
-      }
-    };
-  }
-
-  private class UnsupportedOperationApi implements LongRunningClient {
-    @Override
-    public UnaryCallable<String, OperationSnapshot> getOperationCallable() {
-      throw new UnsupportedOperationException("Didn't expect call to getOperationCallable()");
-    }
-
-    @Override
-    public UnaryCallable<String, Void> cancelOperationCallable() {
-      throw new UnsupportedOperationException("Didn't expect call to cancelOperationCallable()");
-    }
-
-    @Override
-    public UnaryCallable<String, Void> deleteOperationCallable() {
-      throw new UnsupportedOperationException("Didn't expect call to deleteOperationCallable()");
-    }
-  }
-
-  private LongRunningClient mockGetOperation(
-      final StatusCode.Code returnStatusCode, final OperationSnapshot... results) {
-    return new UnsupportedOperationApi() {
-      private UnaryCallable<String, OperationSnapshot> getOperationCallable =
-          mockGetOpSnapshotCallable(returnStatusCode, results);
-
-      @Override
-      public UnaryCallable<String, OperationSnapshot> getOperationCallable() {
-        return getOperationCallable;
-      }
-    };
-  }
-
-  private LongRunningClient mockCancelOperation(final StatusCode.Code returnStatusCode) {
-    return new UnsupportedOperationApi() {
-      private UnaryCallable<String, Void> cancelOperationCallable =
-          new UnaryCallable<String, Void>() {
-            @Override
-            public ApiFuture<Void> futureCall(String request, ApiCallContext context) {
-              return newFuture(returnStatusCode, null);
-            }
-          };
-
-      @Override
-      public UnaryCallable<String, Void> cancelOperationCallable() {
-        return cancelOperationCallable;
-      }
-    };
-  }
-
-  private <ResponseT> ApiFuture<ResponseT> newFuture(
-      StatusCode.Code returnStatusCode, ResponseT response) {
-    if (StatusCode.Code.OK.equals(returnStatusCode)) {
-      return ApiFutures.immediateFuture(response);
-    } else {
-      return ApiFutures.immediateFailedFuture(
-          ApiExceptionFactory.createException(null, FakeStatusCode.of(returnStatusCode), false));
-    }
-  }
-
-  private void assertExceptionMatchesCode(FakeStatusCode code, Throwable exception) {
-    Class<?> expectedClass;
-    switch (code.getCode()) {
-      case CANCELLED:
-        expectedClass = CancelledException.class;
-        break;
-        //      case NOT_FOUND:
-        //        expectedClass = NotFoundException.class;
-        //        break;
-      case UNKNOWN:
-        expectedClass = UnknownException.class;
-        break;
-        //      case INVALID_ARGUMENT:
-        //        expectedClass = InvalidArgumentException.class;
-        //        break;
-      case DEADLINE_EXCEEDED:
-        expectedClass = DeadlineExceededException.class;
-        break;
-      case ALREADY_EXISTS:
-        expectedClass = AlreadyExistsException.class;
-        break;
-        //      case PERMISSION_DENIED:
-        //        expectedClass = PermissionDeniedException.class;
-        //        break;
-        //      case RESOURCE_EXHAUSTED:
-        //        expectedClass = ResourceExhaustedException.class;
-        //        break;
-      case FAILED_PRECONDITION:
-        expectedClass = FailedPreconditionException.class;
-        break;
-        //      case ABORTED:
-        //        expectedClass = AbortedException.class;
-        //        break;
-        //      case OUT_OF_RANGE:
-        //        expectedClass = OutOfRangeException.class;
-        //        break;
-        //      case INTERNAL:
-        //        expectedClass = InternalException.class;
-        //        break;
-      case UNAVAILABLE:
-        expectedClass = UnavailableException.class;
-        break;
-        //      case DATA_LOSS:
-        //        expectedClass = DataLossException.class;
-        //        break;
-        //      case UNAUTHENTICATED:
-        //        expectedClass = UnauthenticatedException.class;
-        //        break;
-
-      default:
-        expectedClass = ApiException.class;
-    }
-    assertThat(exception).isInstanceOf(expectedClass);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/PagedCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/PagedCallSettingsTest.java
deleted file mode 100644
index 25c6b8064..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/PagedCallSettingsTest.java
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.collect.Sets;
-import com.google.common.truth.Truth;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class PagedCallSettingsTest {
-
-  @Test
-  public void testEmptyBuilder() {
-    @SuppressWarnings("unchecked")
-    PagedListResponseFactory<Integer, String, Long> pagedListResponseFactory =
-        Mockito.mock(PagedListResponseFactory.class);
-    PagedCallSettings.Builder<Integer, String, Long> builder =
-        PagedCallSettings.newBuilder(pagedListResponseFactory);
-
-    Truth.assertThat(builder.getPagedListResponseFactory())
-        .isSameInstanceAs(pagedListResponseFactory);
-    Truth.assertThat(builder.getRetryableCodes().size()).isEqualTo(0);
-    Truth.assertThat(builder.getRetrySettings()).isNotNull();
-
-    PagedCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getPagedListResponseFactory())
-        .isSameInstanceAs(pagedListResponseFactory);
-    Truth.assertThat(settings.getRetryableCodes().size()).isEqualTo(0);
-    Truth.assertThat(settings.getRetrySettings()).isNotNull();
-  }
-
-  @Test
-  public void testBuilder() {
-    @SuppressWarnings("unchecked")
-    PagedListResponseFactory<Integer, String, Long> pagedListResponseFactory =
-        Mockito.mock(PagedListResponseFactory.class);
-    PagedCallSettings.Builder<Integer, String, Long> builder =
-        PagedCallSettings.newBuilder(pagedListResponseFactory);
-
-    Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    builder.setRetryableCodes(retryCodes);
-    builder.setRetrySettings(retrySettings);
-
-    Truth.assertThat(builder.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(builder.getRetrySettings()).isEqualTo(retrySettings);
-
-    PagedCallSettings settings = builder.build();
-
-    Truth.assertThat(settings.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(settings.getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void testBuilderFromSettings() throws Exception {
-    @SuppressWarnings("unchecked")
-    PagedListResponseFactory<Integer, String, Long> pagedListResponseFactory =
-        Mockito.mock(PagedListResponseFactory.class);
-    PagedCallSettings.Builder<Integer, String, Long> builder =
-        PagedCallSettings.newBuilder(pagedListResponseFactory);
-
-    Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    builder.setRetryableCodes(retryCodes);
-    builder.setRetrySettings(retrySettings);
-
-    Truth.assertThat(builder.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(builder.getRetrySettings()).isEqualTo(retrySettings);
-
-    PagedCallSettings settings = builder.build();
-    PagedCallSettings.Builder newBuilder = settings.toBuilder();
-
-    Truth.assertThat(newBuilder.getRetryableCodes().size()).isEqualTo(1);
-    Truth.assertThat(newBuilder.getRetrySettings()).isEqualTo(retrySettings);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/PagedCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/PagedCallableTest.java
deleted file mode 100644
index de1dfaf6b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/PagedCallableTest.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakePagedApi.ListIntegersPagedResponse;
-import com.google.api.gax.rpc.testing.FakePagedApi.ListIntegersPagedResponseFactory;
-import com.google.api.gax.rpc.testing.FakePagedApi.PagedStashCallable;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class PagedCallableTest {
-
-  @Test
-  public void futureCall() {
-    List<List<Integer>> results =
-        Arrays.asList(
-            Arrays.asList(0, 1, 2), Arrays.asList(3, 4), Collections.<Integer>emptyList());
-    PagedStashCallable callable = new PagedStashCallable(results);
-    PagedCallable<Integer, List<Integer>, ListIntegersPagedResponse> pagedCallable =
-        new PagedCallable<>(callable, new ListIntegersPagedResponseFactory());
-
-    Truth.assertThat(
-            ImmutableList.copyOf(
-                pagedCallable.call(0, FakeCallContext.createDefault()).iterateAll()))
-        .containsExactly(0, 1, 2, 3, 4)
-        .inOrder();
-  }
-
-  @Test
-  public void testToString() {
-    PagedStashCallable stash = new PagedStashCallable(null);
-    PagedCallable<Integer, List<Integer>, ListIntegersPagedResponse> pagedCallable =
-        new PagedCallable<>(stash, new ListIntegersPagedResponseFactory());
-    Truth.assertThat(pagedCallable.toString()).contains("paged");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/PagingTest.java b/gax/src/test/java/com/google/api/gax/rpc/PagingTest.java
deleted file mode 100644
index e1655b6bf..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/PagingTest.java
+++ /dev/null
@@ -1,187 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.paging.FixedSizeCollection;
-import com.google.api.gax.paging.Page;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakePagedApi.ListIntegersPagedResponse;
-import com.google.api.gax.rpc.testing.FakePagedApi.ListIntegersPagedResponseFactory;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.api.pathtemplate.ValidationException;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class PagingTest {
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    clientContext =
-        ClientContext.newBuilder()
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @SuppressWarnings("unchecked")
-  UnaryCallable<Integer, List<Integer>> callIntList = Mockito.mock(UnaryCallable.class);
-
-  @Test
-  public void nonPaged() {
-    ArgumentCaptor<Integer> requestCapture = ArgumentCaptor.forClass(Integer.class);
-    Mockito.when(callIntList.futureCall(requestCapture.capture(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1, 2)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(3, 4)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-    UnaryCallable<Integer, List<Integer>> callable =
-        FakeCallableFactory.createUnpagedCallable(
-            callIntList,
-            PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-            clientContext);
-    Truth.assertThat(ImmutableList.copyOf(callable.call(0))).containsExactly(0, 1, 2).inOrder();
-    Truth.assertThat(ImmutableList.copyOf(callable.call(2))).containsExactly(3, 4).inOrder();
-    Truth.assertThat(ImmutableList.copyOf(callable.call(4))).isEmpty();
-    Truth.assertThat(requestCapture.getAllValues()).containsExactly(0, 2, 4).inOrder();
-  }
-
-  @Test
-  public void paged() {
-    ArgumentCaptor<Integer> requestCapture = ArgumentCaptor.forClass(Integer.class);
-    Mockito.when(callIntList.futureCall(requestCapture.capture(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1, 2)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(3, 4)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-    UnaryCallable<Integer, ListIntegersPagedResponse> callable =
-        FakeCallableFactory.createPagedCallable(
-            callIntList,
-            PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-            clientContext);
-    Truth.assertThat(ImmutableList.copyOf(callable.call(0).iterateAll()))
-        .containsExactly(0, 1, 2, 3, 4)
-        .inOrder();
-    Truth.assertThat(requestCapture.getAllValues()).containsExactly(0, 2, 4).inOrder();
-  }
-
-  @Test
-  public void pagedByPage() {
-    ArgumentCaptor<Integer> requestCapture = ArgumentCaptor.forClass(Integer.class);
-    Mockito.when(callIntList.futureCall(requestCapture.capture(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1, 2)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(3, 4)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-
-    Page<Integer> page =
-        FakeCallableFactory.createPagedCallable(
-                callIntList,
-                PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-                clientContext)
-            .call(0)
-            .getPage();
-
-    Truth.assertThat(page.getValues()).containsExactly(0, 1, 2).inOrder();
-    Truth.assertThat(page.hasNextPage()).isTrue();
-
-    page = page.getNextPage();
-    Truth.assertThat(page.getValues()).containsExactly(3, 4).inOrder();
-    Truth.assertThat(page.hasNextPage()).isTrue();
-
-    page = page.getNextPage();
-    Truth.assertThat(page.getValues()).isEmpty();
-    Truth.assertThat(page.hasNextPage()).isFalse();
-    Truth.assertThat(page.getNextPage()).isNull();
-    Truth.assertThat(requestCapture.getAllValues()).containsExactly(0, 2, 4).inOrder();
-  }
-
-  @Test
-  public void pagedByFixedSizeCollection() {
-    ArgumentCaptor<Integer> requestCapture = ArgumentCaptor.forClass(Integer.class);
-    Mockito.when(callIntList.futureCall(requestCapture.capture(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1, 2)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(3, 4)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(5, 6, 7)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-    FixedSizeCollection<Integer> fixedSizeCollection =
-        FakeCallableFactory.createPagedCallable(
-                callIntList,
-                PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-                clientContext)
-            .call(0)
-            .expandToFixedSizeCollection(5);
-
-    Truth.assertThat(fixedSizeCollection.getValues()).containsExactly(0, 1, 2, 3, 4).inOrder();
-    Truth.assertThat(fixedSizeCollection.getNextCollection().getValues())
-        .containsExactly(5, 6, 7)
-        .inOrder();
-    Truth.assertThat(requestCapture.getAllValues()).containsExactly(0, 2, 4, 7).inOrder();
-  }
-
-  @Test(expected = ValidationException.class)
-  public void pagedFixedSizeCollectionTooManyElements() {
-    Mockito.when(callIntList.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1, 2)))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(3, 4)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-
-    FakeCallableFactory.createPagedCallable(
-            callIntList,
-            PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-            clientContext)
-        .call(0)
-        .expandToFixedSizeCollection(4);
-  }
-
-  @Test(expected = ValidationException.class)
-  public void pagedFixedSizeCollectionTooSmallCollectionSize() {
-    Mockito.when(callIntList.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(ApiFutures.immediateFuture(Arrays.asList(0, 1)))
-        .thenReturn(ApiFutures.immediateFuture(Collections.<Integer>emptyList()));
-
-    FakeCallableFactory.createPagedCallable(
-            callIntList,
-            PagedCallSettings.newBuilder(new ListIntegersPagedResponseFactory()).build(),
-            clientContext)
-        .call(0)
-        .expandToFixedSizeCollection(2);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/RequestParamsBuilderTest.java b/gax/src/test/java/com/google/api/gax/rpc/RequestParamsBuilderTest.java
deleted file mode 100644
index 30f4d7e62..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/RequestParamsBuilderTest.java
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * Copyright 2022 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.pathtemplate.PathTemplate;
-import java.util.Map;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class RequestParamsBuilderTest {
-
-  private RequestParamsBuilder requestParamsBuilder;
-
-  @Before
-  public void setUp() {
-    requestParamsBuilder = RequestParamsBuilder.create();
-  }
-
-  @Test
-  public void add_happyPath() {
-    Map<String, String> actual =
-        getRoutingHeaders(
-            "projects/**/{table_location=instances/*}",
-            "projects/my_cozy_home/instances/living_room");
-    assertThat(actual).containsExactly("table_location", "instances/living_room");
-  }
-
-  @Test
-  public void build_shouldKeepLastEntryIfMultipleEntriesHaveTheSameKeyRatherThanErrorOut() {
-    requestParamsBuilder.add(
-        "projects/my_cozy_home/instances/living_room",
-        "table_location",
-        PathTemplate.create("projects/**/{table_location=instances/*}"));
-    requestParamsBuilder.add(
-        "projects/my_cozy_home/instances/living_room",
-        "table_location",
-        PathTemplate.create("{table_location=**}"));
-    requestParamsBuilder.add(
-        "projects/my_cozy_home/instances/living_room",
-        "routing_id",
-        PathTemplate.create("{routing_id=**}"));
-    Map<String, String> actual = requestParamsBuilder.build();
-
-    // Should contain two entries instead of three, also should only keep the last entry if there
-    // are multiple entries with the same key
-    assertThat(actual)
-        .containsExactly(
-            "table_location",
-            "projects/my_cozy_home/instances/living_room",
-            "routing_id",
-            "projects/my_cozy_home/instances/living_room");
-  }
-
-  @Test
-  public void add_matchedValuesWithNoRoutingHeaderKey() {
-    Map<String, String> actual = getRoutingHeaders("projects/**", "projects/my_cozy_home/");
-    assertThat(actual).isEmpty();
-  }
-
-  @Test
-  public void add_emptyMatchedValues() {
-    Map<String, String> actual =
-        getRoutingHeaders("projects/**/{table_location=instances/*}", "projects/does_not_matter");
-    assertThat(actual).isEmpty();
-  }
-
-  @Test
-  public void add_nullFieldValue() {
-    Map<String, String> actual = getRoutingHeaders("projects/**", null);
-    assertThat(actual).isEmpty();
-  }
-
-  private Map<String, String> getRoutingHeaders(String patternString, String fieldValue) {
-    PathTemplate pathTemplate = PathTemplate.create(patternString);
-    requestParamsBuilder.add(fieldValue, "table_location", pathTemplate);
-    return requestParamsBuilder.build();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/RequestUrlParamsEncoderTest.java b/gax/src/test/java/com/google/api/gax/rpc/RequestUrlParamsEncoderTest.java
deleted file mode 100644
index 3239bd148..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/RequestUrlParamsEncoderTest.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.mockito.Mockito.when;
-
-import com.google.common.collect.ImmutableMap;
-import java.util.Collections;
-import java.util.Map;
-import org.junit.Test;
-import org.mockito.Mockito;
-
-public class RequestUrlParamsEncoderTest {
-
-  @Test
-  public void testEncodeValidationSuccess() throws Exception {
-    @SuppressWarnings("unchecked")
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(2, ImmutableMap.of("param1", "value+1", "param2", "value+2+%26"));
-
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, true);
-    String encodedParams = encoder.encode(2);
-
-    assertEquals("param1=value+1&param2=value+2+%26", encodedParams);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testEncodeValidationFail() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, ImmutableMap.of("param1", "value+1", "param2", "value+2+&"));
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, true);
-    encoder.encode(1);
-  }
-
-  @Test
-  public void testEncodeNoValidationSuccess() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, ImmutableMap.of("param1", "value+1", "param2", "value+2+&"));
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    String encodedParams = encoder.encode(1);
-
-    assertEquals("param1=value+1&param2=value+2+&", encodedParams);
-  }
-
-  @Test(expected = IllegalArgumentException.class)
-  public void testEncodeNullName() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, Collections.singletonMap((String) null, "value1"));
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    encoder.encode(1);
-  }
-
-  @Test
-  public void testEncodeNullValue() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, Collections.singletonMap("param1", (String) null));
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    String encodedParams = encoder.encode(1);
-    assertEquals("", encodedParams);
-  }
-
-  @Test
-  public void testEncodeEmptyValue() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, Collections.singletonMap("param1", ""));
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    String encodedParams = encoder.encode(1);
-    assertEquals("param1=", encodedParams);
-  }
-
-  @Test
-  public void testEncodeNullAndEmptyParams() throws Exception {
-    RequestParamsExtractor<Integer> extractor =
-        getMockExtractor(1, Collections.<String, String>emptyMap());
-    RequestUrlParamsEncoder<Integer> encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    String encodedParams = encoder.encode(1);
-    assertEquals("", encodedParams);
-
-    extractor = getMockExtractor(1, null);
-    encoder = new RequestUrlParamsEncoder<>(extractor, false);
-    NullPointerException exception = null;
-    try {
-      encoder.encode(1);
-    } catch (NullPointerException e) {
-      exception = e;
-    }
-    assertNotNull(exception);
-  }
-
-  private RequestParamsExtractor<Integer> getMockExtractor(
-      Integer input, Map<String, String> output) {
-    @SuppressWarnings("unchecked")
-    RequestParamsExtractor<Integer> extractor =
-        (RequestParamsExtractor<Integer>) Mockito.mock(RequestParamsExtractor.class);
-    when(extractor.extract(input)).thenReturn(output);
-    return extractor;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/RetryingTest.java b/gax/src/test/java/com/google/api/gax/rpc/RetryingTest.java
deleted file mode 100644
index b58bd2c2c..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/RetryingTest.java
+++ /dev/null
@@ -1,454 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.core.RecordingScheduler;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Sets;
-import com.google.common.truth.Truth;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.UncheckedExecutionException;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class RetryingTest {
-
-  @SuppressWarnings("unchecked")
-  private UnaryCallable<Integer, Integer> callInt = Mockito.mock(UnaryCallable.class);
-
-  private RecordingScheduler executor;
-  private FakeApiClock fakeClock;
-  private ClientContext clientContext;
-
-  private static final RetrySettings FAST_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(2L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(2L))
-          .setInitialRpcTimeout(Duration.ofMillis(2L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofMillis(2L))
-          .setTotalTimeout(Duration.ofMillis(10L))
-          .build();
-  private static final RetrySettings FAILING_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setMaxAttempts(2)
-          .setInitialRetryDelay(Duration.ofNanos(0L))
-          .setRetryDelayMultiplier(1)
-          .setMaxRetryDelay(Duration.ofMillis(0L))
-          .setInitialRpcTimeout(Duration.ofNanos(1L))
-          .setRpcTimeoutMultiplier(1)
-          .setMaxRpcTimeout(Duration.ofNanos(1L))
-          .setTotalTimeout(Duration.ofNanos(1L))
-          .build();
-
-  @Before
-  public void resetClock() {
-    fakeClock = new FakeApiClock(System.nanoTime());
-    executor = RecordingScheduler.create(fakeClock);
-    clientContext =
-        ClientContext.newBuilder()
-            .setExecutor(executor)
-            .setClock(fakeClock)
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @After
-  public void teardown() {
-    executor.shutdownNow();
-  }
-
-  static <V> ApiFuture<V> immediateFailedFuture(Throwable t) {
-    return ApiFutures.<V>immediateFailedFuture(t);
-  }
-
-  @Test
-  public void retry() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetrying(FAST_RETRY_SETTINGS);
-  }
-
-  @Test
-  public void retryUsingContext() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.INTERNAL), false);
-    Mockito.when(callInt.futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetryingUsingContext(
-        FAILING_RETRY_SETTINGS,
-        FakeCallContext.createDefault()
-            .withRetrySettings(FAST_RETRY_SETTINGS)
-            .withRetryableCodes(Sets.newHashSet(StatusCode.Code.INTERNAL)));
-  }
-
-  @Test(expected = ApiException.class)
-  public void retryTotalTimeoutExceeded() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .setMaxRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .build();
-
-    assertRetrying(retrySettings);
-  }
-
-  @Test
-  public void retryUsingContextTotalTimeoutExceeded() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.INTERNAL), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    RetrySettings retrySettings =
-        FAST_RETRY_SETTINGS
-            .toBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .setMaxRetryDelay(Duration.ofMillis(Integer.MAX_VALUE))
-            .build();
-
-    try {
-      assertRetryingUsingContext(
-          FAILING_RETRY_SETTINGS,
-          FakeCallContext.createDefault()
-              .withRetrySettings(retrySettings)
-              .withRetryableCodes(Sets.newHashSet(StatusCode.Code.INTERNAL)));
-      fail("missing expected exception");
-    } catch (ApiException e) {
-      assertEquals(Code.INTERNAL, e.getStatusCode().getCode());
-    }
-  }
-
-  @Test(expected = ApiException.class)
-  public void retryMaxAttemptsExceeded() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetrying(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(2).build());
-  }
-
-  @Test
-  public void retryUsingContextMaxAttemptsExceeded() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.INTERNAL), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    try {
-      assertRetryingUsingContext(
-          FAILING_RETRY_SETTINGS,
-          FakeCallContext.createDefault()
-              .withRetrySettings(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(2).build())
-              .withRetryableCodes(Sets.newHashSet(StatusCode.Code.INTERNAL)));
-      fail("missing expected exception");
-    } catch (ApiException e) {
-      assertEquals(Code.INTERNAL, e.getStatusCode().getCode());
-    }
-  }
-
-  @Test
-  public void retryWithinMaxAttempts() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetrying(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(3).build());
-  }
-
-  @Test
-  public void retryUsingContextWithinMaxAttempts() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.INTERNAL), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetryingUsingContext(
-        FAILING_RETRY_SETTINGS,
-        FakeCallContext.createDefault()
-            .withRetrySettings(FAST_RETRY_SETTINGS.toBuilder().setMaxAttempts(3).build())
-            .withRetryableCodes(Sets.newHashSet(StatusCode.Code.INTERNAL)));
-  }
-
-  @Test
-  public void retryWithOnlyMaxAttempts() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.immediateFuture(2));
-
-    RetrySettings retrySettings = RetrySettings.newBuilder().setMaxAttempts(3).build();
-
-    assertRetrying(retrySettings);
-    Mockito.verify(callInt, Mockito.times(3))
-        .futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any());
-  }
-
-  @Test
-  public void retryUsingContextWithOnlyMaxAttempts() {
-    Throwable throwable =
-        new UnavailableException(null, FakeStatusCode.of(StatusCode.Code.INTERNAL), false);
-    Mockito.when(callInt.futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.immediateFuture(2));
-
-    RetrySettings retrySettings = RetrySettings.newBuilder().setMaxAttempts(3).build();
-
-    assertRetryingUsingContext(
-        FAILING_RETRY_SETTINGS,
-        FakeCallContext.createDefault()
-            .withRetrySettings(retrySettings)
-            .withRetryableCodes(Sets.newHashSet(StatusCode.Code.INTERNAL)));
-    Mockito.verify(callInt, Mockito.times(3))
-        .futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any());
-  }
-
-  @Test
-  public void retryWithoutRetrySettings() {
-    Mockito.when(callInt.futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any()))
-        .thenReturn(ApiFutures.immediateFuture(2));
-
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-
-    assertRetrying(retrySettings);
-    Mockito.verify(callInt).futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any());
-  }
-
-  @Test
-  public void retryUsingContextWithoutRetrySettings() {
-    Mockito.when(callInt.futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any()))
-        .thenReturn(ApiFutures.immediateFuture(2));
-
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-
-    assertRetryingUsingContext(
-        FAILING_RETRY_SETTINGS, FakeCallContext.createDefault().withRetrySettings(retrySettings));
-    Mockito.verify(callInt).futureCall(Mockito.<Integer>any(), Mockito.<ApiCallContext>any());
-  }
-
-  @Test
-  public void retryOnStatusUnknown() {
-    Throwable throwable =
-        new UnknownException(null, FakeStatusCode.of(StatusCode.Code.UNKNOWN), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-
-    assertRetrying(FAST_RETRY_SETTINGS);
-  }
-
-  @Test
-  public void retryOnUnexpectedException() {
-    Throwable throwable =
-        new UnknownException("foobar", null, FakeStatusCode.of(StatusCode.Code.UNKNOWN), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable));
-    try {
-      assertRetrying(FAST_RETRY_SETTINGS);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (ApiException expected) {
-      Truth.assertThat(expected).isSameInstanceAs(throwable);
-    }
-  }
-
-  @Test
-  public void retryNoRecover() {
-    Throwable throwable =
-        new FailedPreconditionException(
-            "foobar", null, FakeStatusCode.of(StatusCode.Code.FAILED_PRECONDITION), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-    try {
-      assertRetrying(FAST_RETRY_SETTINGS);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (ApiException expected) {
-      Truth.assertThat(expected).isSameInstanceAs(throwable);
-    }
-  }
-
-  @Test
-  public void retryUsingContextNoRecover() {
-    Throwable throwable =
-        new FailedPreconditionException(
-            "foobar", null, FakeStatusCode.of(StatusCode.Code.FAILED_PRECONDITION), false);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable))
-        .thenReturn(ApiFutures.<Integer>immediateFuture(2));
-    try {
-      assertRetryingUsingContext(
-          FAILING_RETRY_SETTINGS,
-          FakeCallContext.createDefault()
-              .withRetrySettings(FAST_RETRY_SETTINGS)
-              .withRetryableCodes(
-                  Sets.newHashSet(Code.UNAVAILABLE, Code.DEADLINE_EXCEEDED, Code.UNKNOWN)));
-      Assert.fail("Callable should have thrown an exception");
-    } catch (ApiException expected) {
-      Truth.assertThat(expected).isSameInstanceAs(throwable);
-    }
-  }
-
-  @Test
-  public void retryKeepFailing() {
-    Throwable throwable =
-        new UnavailableException(
-            "foobar", null, FakeStatusCode.of(StatusCode.Code.UNAVAILABLE), true);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(throwable));
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(FAST_RETRY_SETTINGS);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    // Need to advance time inside the call.
-    ApiFuture<Integer> future = callable.futureCall(1);
-    try {
-      Futures.getUnchecked(future);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (UncheckedExecutionException expected) {
-      Truth.assertThat(expected).hasCauseThat().isSameInstanceAs(throwable);
-    }
-  }
-
-  @Test
-  public void testKnownStatusCode() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of(StatusCode.Code.UNAVAILABLE);
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(
-            RetryingTest.<Integer>immediateFailedFuture(
-                new FailedPreconditionException(
-                    "known", null, FakeStatusCode.of(StatusCode.Code.FAILED_PRECONDITION), false)));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(retryable)
-            .build();
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    try {
-      callable.call(1);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (FailedPreconditionException expected) {
-      Truth.assertThat(expected.getMessage()).isEqualTo("known");
-    }
-  }
-
-  @Test
-  public void testUnknownStatusCode() {
-    ImmutableSet<StatusCode.Code> retryable = ImmutableSet.of();
-    Mockito.when(callInt.futureCall((Integer) Mockito.any(), (ApiCallContext) Mockito.any()))
-        .thenReturn(RetryingTest.<Integer>immediateFailedFuture(new RuntimeException("unknown")));
-    UnaryCallSettings<Integer, Integer> callSettings =
-        UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-            .setRetryableCodes(retryable)
-            .build();
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    try {
-      callable.call(1);
-      Assert.fail("Callable should have thrown an exception");
-    } catch (RuntimeException expected) {
-      Truth.assertThat(expected).isInstanceOf(RuntimeException.class);
-    }
-  }
-
-  public static UnaryCallSettings<Integer, Integer> createSettings(RetrySettings retrySettings) {
-    return UnaryCallSettings.<Integer, Integer>newUnaryCallSettingsBuilder()
-        .setRetryableCodes(Code.UNAVAILABLE)
-        .setRetrySettings(retrySettings)
-        .build();
-  }
-
-  private void assertRetrying(RetrySettings retrySettings) {
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(retrySettings);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    Truth.assertThat(callable.call(1)).isEqualTo(2);
-  }
-
-  private void assertRetryingUsingContext(RetrySettings retrySettings, ApiCallContext context) {
-    UnaryCallSettings<Integer, Integer> callSettings = createSettings(retrySettings);
-    UnaryCallable<Integer, Integer> callable =
-        FakeCallableFactory.createUnaryCallable(callInt, callSettings, clientContext);
-    Truth.assertThat(callable.call(1, context)).isEqualTo(2);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamTest.java b/gax/src/test/java/com/google/api/gax/rpc/ServerStreamTest.java
deleted file mode 100644
index b0cdc30ce..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamTest.java
+++ /dev/null
@@ -1,237 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockStreamController;
-import com.google.common.collect.Lists;
-import com.google.common.truth.Truth;
-import java.util.Iterator;
-import java.util.List;
-import java.util.NoSuchElementException;
-import java.util.concurrent.Callable;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ServerStreamTest {
-  private ServerStream<Integer> stream;
-  private MockStreamController<Integer> controller;
-  private ExecutorService executor;
-
-  @Before
-  public void setUp() {
-    stream = new ServerStream<>();
-    controller = new MockStreamController<>(stream.observer());
-
-    stream.observer().onStart(controller);
-    executor = Executors.newCachedThreadPool();
-  }
-
-  @After
-  public void tearDown() {
-    executor.shutdownNow();
-  }
-
-  @Test
-  public void testEmptyStream() {
-    stream.observer().onComplete();
-
-    Truth.assertThat(Lists.newArrayList(stream)).isEmpty();
-  }
-
-  @Test
-  public void testMultipleItemStream() throws Exception {
-    Future<Void> producerFuture =
-        executor.submit(
-            new Callable<Void>() {
-              @Override
-              public Void call() {
-                for (int i = 0; i < 5; i++) {
-                  int requestCount = controller.popLastPull();
-
-                  Truth.assertWithMessage("ServerStream should request one item at a time")
-                      .that(requestCount)
-                      .isEqualTo(1);
-
-                  stream.observer().onResponse(i);
-                }
-                stream.observer().onComplete();
-                return null;
-              }
-            });
-
-    Future<List<Integer>> consumerFuture =
-        executor.submit(
-            new Callable<List<Integer>>() {
-              @Override
-              public List<Integer> call() {
-                return Lists.newArrayList(stream);
-              }
-            });
-
-    producerFuture.get(60, TimeUnit.SECONDS);
-    List<Integer> results = consumerFuture.get();
-    Truth.assertThat(results).containsExactly(0, 1, 2, 3, 4);
-  }
-
-  @Test
-  public void testEarlyTermination() throws Exception {
-    Future<Void> taskFuture =
-        executor.submit(
-            new Callable<Void>() {
-              @Override
-              public Void call() {
-                int i = 0;
-                while (controller.popLastPull() > 0) {
-                  stream.observer().onResponse(i++);
-                }
-                controller.waitForCancel();
-                stream.observer().onError(new CancellationException("cancelled"));
-                return null;
-              }
-            });
-
-    List<Integer> results = Lists.newArrayList();
-    for (Integer result : stream) {
-      results.add(result);
-
-      if (result == 1) {
-        stream.cancel();
-      }
-    }
-
-    taskFuture.get(30, TimeUnit.SECONDS);
-
-    Truth.assertThat(results).containsExactly(0, 1);
-  }
-
-  @Test
-  public void testErrorPropagation() {
-    ClassCastException e = new ClassCastException("fake error");
-
-    stream.observer().onError(e);
-
-    Throwable actualError = null;
-    try {
-      Truth.assertThat(Lists.newArrayList(stream)).isNotNull();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-
-    Truth.assertThat(actualError).hasMessageThat().contains(e.getMessage());
-    Truth.assertThat(actualError).isEqualTo(e);
-  }
-
-  @Test
-  public void testNoErrorsBetweenHasNextAndNext() {
-    Iterator<Integer> it = stream.iterator();
-
-    controller.popLastPull();
-    stream.observer().onResponse(1);
-
-    Truth.assertThat(it.hasNext()).isTrue();
-
-    RuntimeException fakeError = new RuntimeException("fake");
-    stream.observer().onError(fakeError);
-    Truth.assertThat(it.next()).isEqualTo(1);
-
-    // Now the error should be thrown
-    try {
-      it.next();
-      throw new RuntimeException("ServerStream never threw an error!");
-    } catch (RuntimeException e) {
-      Truth.assertThat(e).isSameInstanceAs(fakeError);
-    }
-  }
-
-  @Test
-  public void testReady() {
-    Iterator<Integer> it = stream.iterator();
-    Truth.assertThat(stream.isReceiveReady()).isFalse();
-
-    controller.popLastPull();
-    stream.observer().onResponse(1);
-    Truth.assertThat(stream.isReceiveReady()).isTrue();
-
-    it.next();
-    Truth.assertThat(stream.isReceiveReady()).isFalse();
-  }
-
-  @Test
-  public void testNextAfterEOF() {
-    Iterator<Integer> it = stream.iterator();
-    stream.observer().onComplete();
-
-    // Precondition
-    Truth.assertThat(it.hasNext()).isFalse();
-
-    Throwable actualError = null;
-    try {
-      it.next();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    Truth.assertThat(actualError).isInstanceOf(NoSuchElementException.class);
-  }
-
-  @Test
-  public void testAfterError() {
-    Iterator<Integer> it = stream.iterator();
-
-    RuntimeException expectError = new RuntimeException("my upstream error");
-    stream.observer().onError(expectError);
-
-    Throwable actualError = null;
-
-    try {
-      @SuppressWarnings("unused")
-      boolean ignored = it.hasNext();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-
-    Truth.assertThat(actualError).isEqualTo(expectError);
-
-    try {
-      it.next();
-    } catch (Throwable t) {
-      actualError = t;
-    }
-    Truth.assertThat(actualError).isEqualTo(expectError);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingAttemptCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingAttemptCallableTest.java
deleted file mode 100644
index a0c8b833f..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingAttemptCallableTest.java
+++ /dev/null
@@ -1,524 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.retrying.ServerStreamingAttemptException;
-import com.google.api.gax.retrying.StreamResumptionStrategy;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeApiException;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCall;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCallable;
-import com.google.api.gax.tracing.BaseApiTracer;
-import com.google.common.collect.Queues;
-import com.google.common.truth.Truth;
-import java.util.concurrent.BlockingDeque;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class ServerStreamingAttemptCallableTest {
-  private MockServerStreamingCallable<String, String> innerCallable;
-  private AccumulatingObserver observer;
-  private FakeRetryingFuture fakeRetryingFuture;
-  private StreamResumptionStrategy<String, String> resumptionStrategy;
-  private static Duration totalTimeout = Duration.ofHours(1);
-  private FakeCallContext mockedCallContext;
-
-  @Before
-  public void setUp() {
-    innerCallable = new MockServerStreamingCallable<>();
-    observer = new AccumulatingObserver(true);
-    resumptionStrategy = new MyStreamResumptionStrategy();
-    mockedCallContext = Mockito.mock(FakeCallContext.class);
-  }
-
-  private ServerStreamingAttemptCallable<String, String> createCallable() {
-    return createCallable(FakeCallContext.createDefault());
-  }
-
-  private ServerStreamingAttemptCallable<String, String> createCallable(ApiCallContext context) {
-    ServerStreamingAttemptCallable<String, String> callable =
-        new ServerStreamingAttemptCallable<>(
-            innerCallable, resumptionStrategy, "request", context, observer);
-
-    fakeRetryingFuture = new FakeRetryingFuture(callable);
-    callable.setExternalFuture(fakeRetryingFuture);
-
-    return callable;
-  }
-
-  @Test
-  public void testUserProvidedContextTimeout() {
-    // Mock up the ApiCallContext as if the user provided a timeout and streamWaitTimeout.
-    Mockito.doReturn(BaseApiTracer.getInstance()).when(mockedCallContext).getTracer();
-    Mockito.doReturn(Duration.ofHours(5)).when(mockedCallContext).getTimeout();
-    Mockito.doReturn(Duration.ofHours(5)).when(mockedCallContext).getStreamWaitTimeout();
-
-    ServerStreamingAttemptCallable<String, String> callable = createCallable(mockedCallContext);
-    callable.start();
-
-    // Ensure that the callable did not overwrite the user provided timeouts
-    Mockito.verify(mockedCallContext, Mockito.times(1)).getTimeout();
-    Mockito.verify(mockedCallContext, Mockito.never()).withTimeout(totalTimeout);
-    Mockito.verify(mockedCallContext, Mockito.times(1)).getStreamWaitTimeout();
-    Mockito.verify(mockedCallContext, Mockito.never())
-        .withStreamWaitTimeout(Mockito.any(Duration.class));
-
-    // Should notify outer observer
-    Truth.assertThat(observer.controller).isNotNull();
-
-    // Should configure the inner controller correctly.
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isTrue();
-    Truth.assertThat(call.getRequest()).isEqualTo("request");
-
-    // Send a response in auto flow mode.
-    call.getController().getObserver().onResponse("response1");
-    call.getController().getObserver().onResponse("response2");
-    call.getController().getObserver().onComplete();
-
-    // Make sure the responses are received
-    Truth.assertThat(observer.responses).containsExactly("response1", "response2").inOrder();
-    fakeRetryingFuture.assertSuccess();
-  }
-
-  @Test
-  public void testNoUserProvidedContextTimeout() {
-    // Mock up the ApiCallContext as if the user did not provide custom timeouts.
-    Mockito.doReturn(BaseApiTracer.getInstance()).when(mockedCallContext).getTracer();
-    Mockito.doReturn(null).when(mockedCallContext).getTimeout();
-    Mockito.doReturn(null).when(mockedCallContext).getStreamWaitTimeout();
-    Mockito.doReturn(mockedCallContext).when(mockedCallContext).withTimeout(totalTimeout);
-    Mockito.doReturn(mockedCallContext)
-        .when(mockedCallContext)
-        .withStreamWaitTimeout(Mockito.any(Duration.class));
-
-    ServerStreamingAttemptCallable<String, String> callable = createCallable(mockedCallContext);
-    callable.start();
-
-    // Ensure that the callable configured the timeouts via the Settings in the
-    // absence of user-defined timeouts.
-    Mockito.verify(mockedCallContext, Mockito.times(1)).getTimeout();
-    Mockito.verify(mockedCallContext, Mockito.times(1)).withTimeout(totalTimeout);
-    Mockito.verify(mockedCallContext, Mockito.times(1)).getStreamWaitTimeout();
-    Mockito.verify(mockedCallContext, Mockito.times(1))
-        .withStreamWaitTimeout(Mockito.any(Duration.class));
-
-    // Should notify outer observer
-    Truth.assertThat(observer.controller).isNotNull();
-
-    // Should configure the inner controller correctly.
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isTrue();
-    Truth.assertThat(call.getRequest()).isEqualTo("request");
-
-    // Send a response in auto flow mode.
-    call.getController().getObserver().onResponse("response1");
-    call.getController().getObserver().onResponse("response2");
-    call.getController().getObserver().onComplete();
-
-    // Make sure the responses are received
-    Truth.assertThat(observer.responses).containsExactly("response1", "response2").inOrder();
-    fakeRetryingFuture.assertSuccess();
-  }
-
-  @Test
-  public void testNoErrorsAutoFlow() {
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    // Should notify outer observer
-    Truth.assertThat(observer.controller).isNotNull();
-
-    // Should configure the inner controller correctly.
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isTrue();
-    Truth.assertThat(call.getRequest()).isEqualTo("request");
-
-    // Send a response in auto flow mode.
-    call.getController().getObserver().onResponse("response1");
-    call.getController().getObserver().onResponse("response2");
-    call.getController().getObserver().onComplete();
-
-    // Make sure the responses are received
-    Truth.assertThat(observer.responses).containsExactly("response1", "response2").inOrder();
-    fakeRetryingFuture.assertSuccess();
-  }
-
-  @Test
-  public void testNoErrorsManualFlow() {
-    observer = new AccumulatingObserver(false);
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    // Should notify outer observer.
-    Truth.assertThat(observer.controller).isNotNull();
-
-    // Should configure the inner controller correctly.
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-    Truth.assertThat(call.getRequest()).isEqualTo("request");
-
-    // Request and send message 1.
-    observer.controller.request(1);
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(1);
-    call.getController().getObserver().onResponse("response1");
-
-    // Request & send message 1.
-    observer.controller.request(1);
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(1);
-    call.getController().getObserver().onResponse("response2");
-
-    call.getController().getObserver().onComplete();
-
-    // Make sure the responses are received
-    Truth.assertThat(observer.responses).containsExactly("response1", "response2").inOrder();
-    fakeRetryingFuture.assertSuccess();
-  }
-
-  @Test
-  @SuppressWarnings("ConstantConditions")
-  public void testInitialRetry() {
-    resumptionStrategy = new MyStreamResumptionStrategy();
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-
-    // Send initial error
-    FakeApiException initialError = new FakeApiException(null, Code.UNAVAILABLE, true);
-    call.getController().getObserver().onError(initialError);
-
-    // Should notify the outer future
-    Throwable outerError = null;
-    try {
-      fakeRetryingFuture.getAttemptResult().get(1, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      outerError = e.getCause();
-    } catch (Throwable e) {
-      outerError = e;
-    }
-    Truth.assertThat(outerError).isInstanceOf(ServerStreamingAttemptException.class);
-    Truth.assertThat(((ServerStreamingAttemptException) outerError).hasSeenResponses()).isFalse();
-    Truth.assertThat(((ServerStreamingAttemptException) outerError).canResume()).isTrue();
-    Truth.assertThat(outerError.getCause()).isEqualTo(initialError);
-
-    // Make the retry call
-    callable.call();
-    call = innerCallable.popLastCall();
-
-    // Verify the request and send a response
-    Truth.assertThat(call.getRequest()).isEqualTo("request > 0");
-  }
-
-  @Test
-  @SuppressWarnings("ConstantConditions")
-  public void testMidRetry() {
-    resumptionStrategy = new MyStreamResumptionStrategy();
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-
-    // Respond to the initial request with a coupple responses and an error.
-    Truth.assertThat(call.getRequest()).isEqualTo("request");
-    call.getController().getObserver().onResponse("response1");
-    call.getController().getObserver().onResponse("response2");
-
-    FakeApiException innerError = new FakeApiException(null, Code.UNAVAILABLE, true);
-    call.getController().getObserver().onError(innerError);
-
-    // Should notify the outer future
-    Throwable outerError = null;
-    try {
-      fakeRetryingFuture.getAttemptResult().get(1, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      outerError = e.getCause();
-    } catch (Throwable e) {
-      outerError = e;
-    }
-    Truth.assertThat(outerError).isInstanceOf(ServerStreamingAttemptException.class);
-    Truth.assertThat(((ServerStreamingAttemptException) outerError).hasSeenResponses()).isTrue();
-    Truth.assertThat(((ServerStreamingAttemptException) outerError).canResume()).isTrue();
-    Truth.assertThat(outerError.getCause()).isEqualTo(innerError);
-
-    // Make the retry call
-    callable.call();
-    call = innerCallable.popLastCall();
-
-    // Verify that the request was narrowed and send a response
-    Truth.assertThat(call.getRequest()).isEqualTo("request > 2");
-    call.getController().getObserver().onResponse("response3");
-    Truth.assertThat(observer.responses)
-        .containsExactly("response1", "response2", "response3")
-        .inOrder();
-  }
-
-  @Test
-  public void testRequestCountIsPreserved() {
-    observer = new AccumulatingObserver(false);
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    observer.controller.request(5);
-
-    Truth.assertThat(observer.controller).isNotNull();
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call).isNotNull();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(5);
-    // decrement
-    call.getController().getObserver().onResponse("response");
-    // and then error
-    call.getController()
-        .getObserver()
-        .onError(new FakeApiException(null, Code.UNAUTHENTICATED, true));
-
-    // Make the retry call
-    callable.call();
-    call = innerCallable.popLastCall();
-
-    // Verify that the count is correct
-    Truth.assertThat(call.getController().popLastPull()).isEqualTo(4);
-  }
-
-  @Test
-  public void testCancel() {
-    observer = new AccumulatingObserver(false);
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    observer.controller.request(1);
-
-    Truth.assertThat(observer.controller).isNotNull();
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-    Truth.assertThat(call).isNotNull();
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
-
-    observer.controller.cancel();
-
-    // Check upstream is cancelled
-    Truth.assertThat(call.getController().isCancelled()).isTrue();
-
-    // and after upstream cancellation is processed, downstream is cancelled, but the cause is
-    // replaced
-    RuntimeException innerException =
-        new RuntimeException("Some internal representation of cancel");
-    call.getController().getObserver().onError(innerException);
-
-    Throwable outerError = null;
-    try {
-      fakeRetryingFuture.getAttemptResult().get(1, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      outerError = e.getCause();
-    } catch (Throwable e) {
-      outerError = e;
-    }
-
-    Truth.assertThat(outerError).isInstanceOf(ServerStreamingAttemptException.class);
-    Truth.assertThat(outerError.getCause()).isInstanceOf(CancellationException.class);
-
-    // Make sure that the stack trace of the cancellation is preserved
-    boolean includesMeInStackTrace = false;
-    for (StackTraceElement e : outerError.getCause().getStackTrace()) {
-      if (ServerStreamingAttemptCallableTest.class.getName().equals(e.getClassName())) {
-        includesMeInStackTrace = true;
-        break;
-      }
-    }
-    Truth.assertWithMessage("Cancel caller included in stack trace")
-        .that(includesMeInStackTrace)
-        .isTrue();
-  }
-
-  @Test
-  public void testResponseSubstitution() {
-    resumptionStrategy =
-        new MyStreamResumptionStrategy() {
-          @Override
-          public String processResponse(String response) {
-            return super.processResponse(response) + "+suffix";
-          }
-        };
-
-    observer = new AccumulatingObserver(false);
-    ServerStreamingAttemptCallable<String, String> callable = createCallable();
-    callable.start();
-
-    MockServerStreamingCall<String, String> call = innerCallable.popLastCall();
-
-    // Send initial response & then error
-    call.getController().getObserver().onResponse("first");
-    call.getController().getObserver().onError(new FakeApiException(null, Code.UNAVAILABLE, true));
-
-    // Make the retry call
-    callable.call();
-    call = innerCallable.popLastCall();
-
-    // Send another couple of responses (the first one will be ignored)
-    call.getController().getObserver().onResponse("second");
-    call.getController().getObserver().onResponse("third");
-    call.getController().getObserver().onComplete();
-
-    // Verify the request and send a response
-    Truth.assertThat(observer.responses)
-        .containsExactly("first+suffix", "second+suffix", "third+suffix");
-  }
-
-  static class MyStreamResumptionStrategy implements StreamResumptionStrategy<String, String> {
-    private int responseCount;
-
-    @Override
-    public StreamResumptionStrategy<String, String> createNew() {
-      return new MyStreamResumptionStrategy();
-    }
-
-    @Override
-    public String processResponse(String response) {
-      responseCount++;
-      return response;
-    }
-
-    @Override
-    public String getResumeRequest(String originalRequest) {
-      return originalRequest + " > " + responseCount;
-    }
-
-    @Override
-    public boolean canResume() {
-      return true;
-    }
-  }
-
-  static class AccumulatingObserver implements ResponseObserver<String> {
-    final boolean autoFlow;
-    StreamController controller;
-    final BlockingDeque<String> responses = Queues.newLinkedBlockingDeque();
-    private Throwable error;
-    private boolean complete;
-
-    AccumulatingObserver(boolean autoFlow) {
-      this.autoFlow = autoFlow;
-    }
-
-    @Override
-    public void onStart(StreamController controller) {
-      this.controller = controller;
-      if (!autoFlow) {
-        controller.disableAutoInboundFlowControl();
-      }
-    }
-
-    @Override
-    public void onResponse(String response) {
-      responses.add(response);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      this.error = t;
-    }
-
-    @Override
-    public void onComplete() {
-      this.complete = true;
-    }
-  }
-
-  private static class FakeRetryingFuture extends AbstractApiFuture<Void>
-      implements RetryingFuture<Void> {
-    private final ServerStreamingAttemptCallable<String, String> attemptCallable;
-    private ApiFuture<Void> attemptFuture;
-    private TimedAttemptSettings attemptSettings;
-
-    FakeRetryingFuture(ServerStreamingAttemptCallable<String, String> attemptCallable) {
-      this.attemptCallable = attemptCallable;
-      attemptSettings =
-          TimedAttemptSettings.newBuilder()
-              .setGlobalSettings(RetrySettings.newBuilder().setTotalTimeout(totalTimeout).build())
-              .setFirstAttemptStartTimeNanos(0)
-              .setAttemptCount(0)
-              .setOverallAttemptCount(0)
-              .setRandomizedRetryDelay(Duration.ofMillis(1))
-              .setRetryDelay(Duration.ofMillis(1))
-              .setRpcTimeout(Duration.ofMinutes(1))
-              .build();
-    }
-
-    @Override
-    public void setAttemptFuture(ApiFuture<Void> attemptFuture) {
-      this.attemptFuture = attemptFuture;
-    }
-
-    @Override
-    public ServerStreamingAttemptCallable<String, String> getCallable() {
-      return attemptCallable;
-    }
-
-    @Override
-    public TimedAttemptSettings getAttemptSettings() {
-      return attemptSettings;
-    }
-
-    @Override
-    public ApiFuture<Void> peekAttemptResult() {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ApiFuture<Void> getAttemptResult() {
-      return attemptFuture;
-    }
-
-    void assertSuccess() {
-      Throwable actualError = null;
-      try {
-        attemptFuture.get(1, TimeUnit.SECONDS);
-      } catch (Throwable t) {
-        actualError = t;
-      }
-      Truth.assertThat(actualError).isNull();
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallSettingsTest.java
deleted file mode 100644
index a14268f8d..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallSettingsTest.java
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.common.collect.ImmutableSet;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class ServerStreamingCallSettingsTest {
-  @Test
-  public void retryableCodesAreNotLost() {
-    Set<Code> codes = ImmutableSet.of(Code.UNAVAILABLE, Code.RESOURCE_EXHAUSTED);
-    ServerStreamingCallSettings.Builder<Object, Object> builder =
-        ServerStreamingCallSettings.newBuilder();
-    builder.setRetryableCodes(codes);
-
-    assertThat(builder.getRetryableCodes()).containsExactlyElementsIn(codes);
-    assertThat(builder.build().getRetryableCodes()).containsExactlyElementsIn(codes);
-    assertThat(builder.build().toBuilder().getRetryableCodes()).containsExactlyElementsIn(codes);
-  }
-
-  @Test
-  public void retryableCodesVarArgs() {
-    ServerStreamingCallSettings.Builder<Object, Object> builder =
-        ServerStreamingCallSettings.newBuilder().setRetryableCodes(Code.UNKNOWN, Code.ABORTED);
-
-    assertThat(builder.getRetryableCodes()).containsExactly(Code.UNKNOWN, Code.ABORTED);
-  }
-
-  @Test
-  public void retryableSettingsAreNotLost() {
-    RetrySettings retrySettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    ServerStreamingCallSettings.Builder<Object, Object> builder =
-        ServerStreamingCallSettings.newBuilder();
-    builder.setRetrySettings(retrySettings);
-
-    assertThat(builder.getRetrySettings()).isEqualTo(retrySettings);
-    assertThat(builder.build().getRetrySettings()).isEqualTo(retrySettings);
-    assertThat(builder.build().toBuilder().getRetrySettings()).isEqualTo(retrySettings);
-  }
-
-  @Test
-  public void idleTimeoutIsNotLost() {
-    Duration idleTimeout = Duration.ofSeconds(5);
-
-    ServerStreamingCallSettings.Builder<Object, Object> builder =
-        ServerStreamingCallSettings.newBuilder();
-    builder.setIdleTimeout(idleTimeout);
-
-    assertThat(builder.getIdleTimeout()).isEqualTo(idleTimeout);
-    assertThat(builder.build().getIdleTimeout()).isEqualTo(idleTimeout);
-    assertThat(builder.build().toBuilder().getIdleTimeout()).isEqualTo(idleTimeout);
-  }
-
-  @Test
-  public void testRetrySettingsBuilder() {
-    RetrySettings initialSettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    ServerStreamingCallSettings.Builder<Object, Object> builder =
-        ServerStreamingCallSettings.newBuilder().setRetrySettings(initialSettings);
-
-    builder.retrySettings().setMaxRetryDelay(Duration.ofMinutes(1));
-
-    assertThat(builder.getRetrySettings().getMaxRetryDelay()).isEqualTo(Duration.ofMinutes(1));
-    assertThat(builder.build().getRetrySettings().getMaxRetryDelay())
-        .isEqualTo(Duration.ofMinutes(1));
-  }
-
-  @Test
-  public void testToString() {
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-    Set<StatusCode.Code> retryableCodes = ImmutableSet.of(StatusCode.Code.DEADLINE_EXCEEDED);
-    Duration idleTime = Duration.ofSeconds(100);
-    ServerStreamingCallSettings serverCallSettings =
-        ServerStreamingCallSettings.newBuilder()
-            .setRetrySettings(retrySettings)
-            .setRetryableCodes(retryableCodes)
-            .setIdleTimeout(idleTime)
-            .build();
-    assertThat(serverCallSettings.toString()).contains("idleTimeout=" + idleTime);
-    assertThat(serverCallSettings.toString()).contains("retryableCodes=" + retryableCodes);
-    assertThat(serverCallSettings.toString()).contains("retrySettings=" + retrySettings);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallableTest.java
deleted file mode 100644
index ca292257f..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingCallableTest.java
+++ /dev/null
@@ -1,269 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeSimpleApi.StashCallable;
-import com.google.api.gax.rpc.testing.FakeStreamingApi.ServerStreamingStashCallable;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableList;
-import com.google.common.truth.Truth;
-import java.util.Arrays;
-import java.util.List;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class ServerStreamingCallableTest {
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    clientContext =
-        ClientContext.newBuilder()
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  @Test
-  public void serverStreaming() {
-    ServerStreamingStashCallable<Integer, Integer> callIntList =
-        new ServerStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    ServerStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createServerStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    AccumulatingStreamObserver responseObserver = new AccumulatingStreamObserver();
-    callable.call(0, responseObserver);
-    Truth.assertThat(ImmutableList.copyOf(responseObserver.getValues()))
-        .containsExactly(0, 1, 2)
-        .inOrder();
-    Truth.assertThat(callIntList.getActualRequest()).isEqualTo(0);
-  }
-
-  @Test
-  public void testServerStreamingCall() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-    ServerStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-    @SuppressWarnings("unchecked")
-    StateCheckingResponseObserver<Integer> observer =
-        Mockito.mock(StateCheckingResponseObserver.class);
-    Integer request = 1;
-    callable.call(request, observer);
-    Truth.assertThat(stashCallable.getActualObserver()).isSameInstanceAs(observer);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    Truth.assertThat(stashCallable.getContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void testServerStreamingCallWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-    ServerStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-    @SuppressWarnings("unchecked")
-    ResponseObserver<Integer> observer = Mockito.mock(StateCheckingResponseObserver.class);
-    Integer request = 1;
-    callable.call(request, observer, context);
-    Truth.assertThat(stashCallable.getActualObserver()).isSameInstanceAs(observer);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void blockingServerStreaming() {
-    ServerStreamingStashCallable<Integer, Integer> callIntList =
-        new ServerStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    ServerStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createServerStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-    Truth.assertThat(ImmutableList.copyOf(callable.call(0))).containsExactly(0, 1, 2).inOrder();
-    Truth.assertThat(callIntList.getActualRequest()).isEqualTo(0);
-  }
-
-  @Test
-  public void testIteratedServerStreamingCall() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-    ServerStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-    Integer request = 1;
-    callable.call(request);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    Truth.assertThat(stashCallable.getContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void testIteratedServerStreamingCallWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-    ServerStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-    Integer request = 1;
-    callable.call(request, context);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void testFirstElementCall() {
-    ServerStreamingStashCallable<Integer, Integer> callIntList =
-        new ServerStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    ServerStreamingCallable<Integer, Integer> streamingCallable =
-        FakeCallableFactory.createServerStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    UnaryCallable<Integer, Integer> callable = streamingCallable.first();
-    Truth.assertThat(callable.call(0)).isEqualTo(0);
-    Truth.assertThat(callIntList.getActualRequest()).isEqualTo(0);
-  }
-
-  @Test
-  public void testFirstElementCallWithDefaultContext() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-
-    final StashCallable<Integer, Integer> stashFirstCallable = new StashCallable<>(11);
-
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<Integer, Integer>() {
-          @Override
-          public UnaryCallable<Integer, Integer> first() {
-            return stashFirstCallable;
-          }
-        };
-
-    UnaryCallable<Integer, Integer> firstCallable =
-        stashCallable.withDefaultCallContext(defaultCallContext).first();
-    Integer request = 1;
-    firstCallable.call(request);
-    Truth.assertThat(stashFirstCallable.getRequest()).isSameInstanceAs(request);
-    Truth.assertThat(stashFirstCallable.getContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void testFirstElementCallWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-
-    UnaryCallable<Integer, Integer> firstCallable =
-        stashCallable.first().withDefaultCallContext(FakeCallContext.createDefault());
-    Integer request = 1;
-    firstCallable.call(request, context);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-
-  @Test
-  public void testAllElementCall() {
-    ServerStreamingStashCallable<Integer, Integer> callIntList =
-        new ServerStreamingStashCallable<>(Arrays.asList(0, 1, 2));
-
-    ServerStreamingCallable<Integer, Integer> streamingCallable =
-        FakeCallableFactory.createServerStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    UnaryCallable<Integer, List<Integer>> callable = streamingCallable.all();
-    Truth.assertThat(callable.call(0)).containsExactly(0, 1, 2).inOrder();
-    Truth.assertThat(callIntList.getActualRequest()).isEqualTo(0);
-  }
-
-  @Test
-  public void testAllElementCallWithDefaultContext() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-
-    UnaryCallable<Integer, List<Integer>> firstCallable =
-        stashCallable.all().withDefaultCallContext(defaultCallContext);
-    Integer request = 1;
-    firstCallable.call(request);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    Truth.assertThat(stashCallable.getContext()).isSameInstanceAs(defaultCallContext);
-  }
-
-  @Test
-  public void testAllElementCallWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    ApiCallContext context =
-        FakeCallContext.createDefault().withChannel(channel).withCredentials(credentials);
-    ServerStreamingStashCallable<Integer, Integer> stashCallable =
-        new ServerStreamingStashCallable<>();
-
-    UnaryCallable<Integer, List<Integer>> firstCallable =
-        stashCallable.all().withDefaultCallContext(FakeCallContext.createDefault());
-    Integer request = 1;
-    firstCallable.call(request, context);
-    Truth.assertThat(stashCallable.getActualRequest()).isSameInstanceAs(request);
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    Truth.assertThat(actualContext.getChannel()).isSameInstanceAs(channel);
-    Truth.assertThat(actualContext.getCredentials()).isSameInstanceAs(credentials);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/SpoolingCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/SpoolingCallableTest.java
deleted file mode 100644
index c968c2c87..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/SpoolingCallableTest.java
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCall;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCallable;
-import com.google.common.truth.Truth;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class SpoolingCallableTest {
-  private MockServerStreamingCallable<String, String> upstream;
-  private SpoolingCallable<String, String> callable;
-
-  @Before
-  public void setup() {
-    upstream = new MockServerStreamingCallable<>();
-    callable = new SpoolingCallable<>(upstream);
-  }
-
-  @Test
-  public void testHappyPath() throws InterruptedException, ExecutionException {
-    ApiFuture<List<String>> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isTrue();
-
-    call.getController().getObserver().onResponse("response1");
-    call.getController().getObserver().onResponse("response2");
-    call.getController().getObserver().onComplete();
-
-    Truth.assertThat(result.get()).containsExactly("response1", "response2").inOrder();
-  }
-
-  @Test
-  public void testEarlyTermination() throws Exception {
-    ApiFuture<List<String>> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    // The caller cancels the stream while receiving responses
-    call.getController().getObserver().onResponse("response1");
-    result.cancel(true);
-    call.getController().getObserver().onResponse("response2");
-
-    // The cancellation should propagate upstream
-    Truth.assertThat(call.getController().isCancelled()).isTrue();
-    // Then we fake a cancellation going the other way (it will be wrapped in StatusRuntimeException
-    // for grpc)
-    call.getController()
-        .getObserver()
-        .onError(new RuntimeException("Some other upstream cancellation indicator"));
-
-    // However the inner cancellation exception will be masked by an outer CancellationException
-    try {
-      result.get();
-      Assert.fail("Callable should have thrown an exception");
-    } catch (CancellationException expected) {
-      Truth.assertThat(expected).hasMessageThat().contains("Task was cancelled.");
-    }
-  }
-
-  @Test
-  public void testNoResults() throws Exception {
-    ApiFuture<List<String>> result = callable.futureCall("request");
-    MockServerStreamingCall<String, String> call = upstream.popLastCall();
-
-    call.getController().getObserver().onComplete();
-
-    Truth.assertThat(result.get()).isEmpty();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/StreamingCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/StreamingCallableTest.java
deleted file mode 100644
index f946aff92..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/StreamingCallableTest.java
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static org.junit.Assert.assertSame;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeCallableFactory;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.FakeStreamingApi.ClientStreamingStashCallable;
-import com.google.api.gax.rpc.testing.FakeTransportChannel;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.truth.Truth;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Set;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class StreamingCallableTest {
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    clientContext =
-        ClientContext.newBuilder()
-            .setDefaultCallContext(FakeCallContext.createDefault())
-            .setTransportChannel(FakeTransportChannel.create(new FakeChannel()))
-            .build();
-  }
-
-  private static class AccumulatingStreamObserver implements ApiStreamObserver<Integer> {
-    private List<Integer> values = new ArrayList<>();
-    private Throwable error;
-    private boolean completed = false;
-
-    @Override
-    public void onNext(Integer value) {
-      values.add(value);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      error = t;
-    }
-
-    @Override
-    public void onCompleted() {
-      completed = true;
-    }
-
-    public List<Integer> getValues() {
-      if (!completed) {
-        throw new IllegalStateException("Stream not completed.");
-      }
-      if (error != null) {
-        throw ApiExceptionFactory.createException(error, FakeStatusCode.of(Code.UNKNOWN), false);
-      }
-      return values;
-    }
-  }
-
-  @Test
-  public void clientStreaming() {
-    ClientStreamingStashCallable<Integer, Integer> callIntList =
-        new ClientStreamingStashCallable<>(100);
-
-    ClientStreamingCallable<Integer, Integer> callable =
-        FakeCallableFactory.createClientStreamingCallable(
-            callIntList,
-            StreamingCallSettings.<Integer, Integer>newBuilder().build(),
-            clientContext);
-
-    AccumulatingStreamObserver responseObserver = new AccumulatingStreamObserver();
-    ApiStreamObserver<Integer> requestObserver = callable.clientStreamingCall(responseObserver);
-    requestObserver.onNext(0);
-    requestObserver.onNext(2);
-    requestObserver.onNext(4);
-    requestObserver.onCompleted();
-
-    Truth.assertThat(ImmutableList.copyOf(responseObserver.getValues()))
-        .containsExactly(100)
-        .inOrder();
-    Truth.assertThat(callIntList.getActualRequests()).containsExactly(0, 2, 4).inOrder();
-  }
-
-  @Test
-  @SuppressWarnings("unchecked")
-  public void testClientStreamingCall() {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    ClientStreamingStashCallable<Integer, Integer> stashCallable =
-        new ClientStreamingStashCallable<>();
-    ApiStreamObserver<Integer> observer = Mockito.mock(ApiStreamObserver.class);
-    ClientStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-    callable.clientStreamingCall(observer);
-    assertSame(observer, stashCallable.getActualObserver());
-    assertSame(defaultCallContext, stashCallable.getContext());
-  }
-
-  @Test
-  @SuppressWarnings("unchecked")
-  public void testClientStreamingCallWithContext() {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    RetrySettings retrySettings = Mockito.mock(RetrySettings.class);
-    Set<StatusCode.Code> retryableCodes =
-        ImmutableSet.of(
-            StatusCode.Code.INTERNAL,
-            StatusCode.Code.UNAVAILABLE,
-            StatusCode.Code.DEADLINE_EXCEEDED);
-    ApiCallContext context =
-        FakeCallContext.createDefault()
-            .withChannel(channel)
-            .withCredentials(credentials)
-            .withRetrySettings(retrySettings)
-            .withRetryableCodes(retryableCodes);
-    ClientStreamingStashCallable<Integer, Integer> stashCallable =
-        new ClientStreamingStashCallable<>();
-    ApiStreamObserver<Integer> observer = Mockito.mock(ApiStreamObserver.class);
-    ClientStreamingCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-    callable.clientStreamingCall(observer, context);
-    assertSame(observer, stashCallable.getActualObserver());
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    assertSame(channel, actualContext.getChannel());
-    assertSame(credentials, actualContext.getCredentials());
-    assertSame(retrySettings, actualContext.getRetrySettings());
-    assertSame(retryableCodes, actualContext.getRetryableCodes());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/StreamingRetryAlgorithmTest.java b/gax/src/test/java/com/google/api/gax/rpc/StreamingRetryAlgorithmTest.java
deleted file mode 100644
index 740000723..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/StreamingRetryAlgorithmTest.java
+++ /dev/null
@@ -1,228 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiClock;
-import com.google.api.gax.retrying.BasicResultRetryAlgorithm;
-import com.google.api.gax.retrying.ExponentialRetryAlgorithm;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.retrying.RetryingContext;
-import com.google.api.gax.retrying.ServerStreamingAttemptException;
-import com.google.api.gax.retrying.StreamingRetryAlgorithm;
-import com.google.api.gax.retrying.TimedAttemptSettings;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class StreamingRetryAlgorithmTest {
-  private static final RetrySettings DEFAULT_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(10L))
-          .setInitialRpcTimeout(Duration.ofMillis(100L))
-          .setMaxAttempts(10)
-          .setMaxRetryDelay(Duration.ofSeconds(10L))
-          .setMaxRpcTimeout(Duration.ofSeconds(30L))
-          .setRetryDelayMultiplier(1.4)
-          .setRpcTimeoutMultiplier(1.5)
-          .setTotalTimeout(Duration.ofMinutes(10L))
-          .build();
-
-  private static final RetrySettings CONTEXT_RETRY_SETTINGS =
-      RetrySettings.newBuilder()
-          .setInitialRetryDelay(Duration.ofMillis(20L))
-          .setInitialRpcTimeout(Duration.ofMillis(200L))
-          .setMaxAttempts(10)
-          .setMaxRetryDelay(Duration.ofSeconds(20L))
-          .setMaxRpcTimeout(Duration.ofSeconds(60L))
-          .setRetryDelayMultiplier(2.4)
-          .setRpcTimeoutMultiplier(2.5)
-          .setTotalTimeout(Duration.ofMinutes(20L))
-          .build();
-
-  @Test
-  public void testFirstAttemptUsesDefaultSettings() {
-    RetryingContext context = mock(RetryingContext.class);
-    BasicResultRetryAlgorithm<String> resultAlgorithm = new BasicResultRetryAlgorithm<>();
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt(context);
-    assertThat(attempt.getGlobalSettings()).isSameInstanceAs(DEFAULT_RETRY_SETTINGS);
-    assertThat(attempt.getRpcTimeout()).isEqualTo(DEFAULT_RETRY_SETTINGS.getInitialRpcTimeout());
-  }
-
-  @Test
-  public void testFirstAttemptUsesContextSettings() {
-    RetryingContext context = mock(RetryingContext.class);
-    when(context.getRetrySettings()).thenReturn(CONTEXT_RETRY_SETTINGS);
-    BasicResultRetryAlgorithm<String> resultAlgorithm = new BasicResultRetryAlgorithm<>();
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    TimedAttemptSettings attempt = algorithm.createFirstAttempt(context);
-    assertThat(attempt.getGlobalSettings()).isSameInstanceAs(CONTEXT_RETRY_SETTINGS);
-    assertThat(attempt.getRpcTimeout()).isEqualTo(CONTEXT_RETRY_SETTINGS.getInitialRpcTimeout());
-  }
-
-  @Test
-  public void testNextAttemptReturnsNullWhenShouldNotRetry() {
-    RetryingContext context = mock(RetryingContext.class);
-    @SuppressWarnings("unchecked")
-    BasicResultRetryAlgorithm<String> resultAlgorithm = mock(BasicResultRetryAlgorithm.class);
-    UnavailableException exception = mock(UnavailableException.class);
-    when(resultAlgorithm.shouldRetry(context, exception, null)).thenReturn(false);
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    TimedAttemptSettings attempt =
-        algorithm.createNextAttempt(context, exception, null, mock(TimedAttemptSettings.class));
-    assertThat(attempt).isNull();
-
-    TimedAttemptSettings attemptWithoutContext =
-        algorithm.createNextAttempt(exception, null, mock(TimedAttemptSettings.class));
-    assertThat(attemptWithoutContext).isNull();
-  }
-
-  @Test
-  public void testNextAttemptReturnsResultAlgorithmSettingsWhenShouldRetry() {
-    RetryingContext context = mock(RetryingContext.class);
-    @SuppressWarnings("unchecked")
-    BasicResultRetryAlgorithm<String> resultAlgorithm = mock(BasicResultRetryAlgorithm.class);
-    UnavailableException exception = mock(UnavailableException.class);
-    when(resultAlgorithm.shouldRetry(context, exception, null)).thenReturn(true);
-    TimedAttemptSettings next = mock(TimedAttemptSettings.class);
-    when(resultAlgorithm.createNextAttempt(
-            Mockito.eq(context),
-            Mockito.eq(exception),
-            Mockito.<String>isNull(),
-            any(TimedAttemptSettings.class)))
-        .thenReturn(next);
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    TimedAttemptSettings first = algorithm.createFirstAttempt(context);
-    TimedAttemptSettings attempt = algorithm.createNextAttempt(context, exception, null, first);
-    assertThat(attempt).isSameInstanceAs(next);
-  }
-
-  @Test
-  public void testNextAttemptResetsTimedSettings() {
-    RetryingContext context = mock(RetryingContext.class);
-    BasicResultRetryAlgorithm<String> resultAlgorithm = new BasicResultRetryAlgorithm<>();
-
-    ServerStreamingAttemptException exception = mock(ServerStreamingAttemptException.class);
-    when(exception.canResume()).thenReturn(true);
-    when(exception.hasSeenResponses()).thenReturn(true);
-    UnavailableException cause = mock(UnavailableException.class);
-    when(exception.getCause()).thenReturn(cause);
-
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    TimedAttemptSettings first = algorithm.createFirstAttempt(context);
-    TimedAttemptSettings second =
-        algorithm.createNextAttempt(context, mock(Exception.class), null, first);
-    TimedAttemptSettings third = algorithm.createNextAttempt(context, exception, null, second);
-    assertThat(third.getFirstAttemptStartTimeNanos())
-        .isEqualTo(first.getFirstAttemptStartTimeNanos());
-    // The timeout values are reset to the second call.
-    assertThat(third.getRpcTimeout()).isEqualTo(second.getRpcTimeout());
-  }
-
-  @Test
-  public void testShouldNotRetryIfAttemptIsNonResumable() {
-    RetryingContext context = mock(RetryingContext.class);
-
-    ServerStreamingAttemptException exception = mock(ServerStreamingAttemptException.class);
-    when(exception.canResume()).thenReturn(false);
-    UnavailableException cause = mock(UnavailableException.class);
-    when(exception.getCause()).thenReturn(cause);
-
-    BasicResultRetryAlgorithm<String> resultAlgorithm = new BasicResultRetryAlgorithm<>();
-
-    ExponentialRetryAlgorithm timedAlgorithm =
-        new ExponentialRetryAlgorithm(DEFAULT_RETRY_SETTINGS, mock(ApiClock.class));
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    // This should return false because the attempt exception indicates that it is non-resumable.
-    boolean shouldRetry =
-        algorithm.shouldRetry(context, exception, null, mock(TimedAttemptSettings.class));
-    assertThat(shouldRetry).isFalse();
-
-    boolean shouldRetryWithoutContext =
-        algorithm.shouldRetry(exception, null, mock(TimedAttemptSettings.class));
-    assertThat(shouldRetryWithoutContext).isFalse();
-  }
-
-  @Test
-  public void testShouldRetryIfAllSayYes() {
-    RetryingContext context = mock(RetryingContext.class);
-
-    ServerStreamingAttemptException exception = mock(ServerStreamingAttemptException.class);
-    when(exception.canResume()).thenReturn(true);
-    UnavailableException cause = mock(UnavailableException.class);
-    when(exception.getCause()).thenReturn(cause);
-
-    BasicResultRetryAlgorithm<String> resultAlgorithm = new BasicResultRetryAlgorithm<>();
-
-    ExponentialRetryAlgorithm timedAlgorithm = mock(ExponentialRetryAlgorithm.class);
-    when(timedAlgorithm.shouldRetry(Mockito.eq(context), any(TimedAttemptSettings.class)))
-        .thenReturn(true);
-    StreamingRetryAlgorithm<String> algorithm =
-        new StreamingRetryAlgorithm<>(resultAlgorithm, timedAlgorithm);
-
-    boolean shouldRetry =
-        algorithm.shouldRetry(context, exception, null, mock(TimedAttemptSettings.class));
-    assertThat(shouldRetry).isTrue();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/TranslatingUnaryCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/TranslatingUnaryCallableTest.java
deleted file mode 100644
index af9534143..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/TranslatingUnaryCallableTest.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.common.truth.Truth;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class TranslatingUnaryCallableTest {
-
-  @Test
-  public void translate() throws Exception {
-    TranslatingUnaryCallable<Integer, Integer, String, String> callable =
-        TranslatingUnaryCallable.create(
-            new UnaryCallable<Integer, Integer>() {
-              @Override
-              public ApiFuture<Integer> futureCall(Integer request, ApiCallContext context) {
-                return ApiFutures.immediateFuture(request + 1);
-              }
-            },
-            new ApiFunction<String, Integer>() {
-              @Override
-              public Integer apply(String s) {
-                return Integer.parseInt(s);
-              }
-            },
-            new ApiFunction<Integer, String>() {
-              @Override
-              public String apply(Integer integer) {
-                return integer.toString();
-              }
-            });
-    Truth.assertThat(callable.futureCall("3").get()).isEqualTo("4");
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/UnaryCallSettingsTest.java b/gax/src/test/java/com/google/api/gax/rpc/UnaryCallSettingsTest.java
deleted file mode 100644
index 6838d5725..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/UnaryCallSettingsTest.java
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.common.collect.ImmutableSet;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class UnaryCallSettingsTest {
-
-  @Test
-  public void testSetSimpleTimeoutNoRetries() {
-    UnaryCallSettings.Builder<?, ?> builder = new UnaryCallSettings.Builder<Object, Object>();
-    builder.setSimpleTimeoutNoRetries(Duration.ofSeconds(13));
-
-    assertThat(builder.getRetryableCodes().size()).isEqualTo(0);
-    assertThat(builder.getRetrySettings().getMaxAttempts()).isEqualTo(1);
-    assertThat(builder.getRetrySettings().getTotalTimeout()).isEqualTo(Duration.ofSeconds(13));
-  }
-
-  @Test
-  public void testEquals() {
-    UnaryCallSettings.Builder<?, ?> builder = new UnaryCallSettings.Builder<Object, Object>();
-    builder.setSimpleTimeoutNoRetries(Duration.ofSeconds(13));
-
-    UnaryCallSettings<?, ?> settings13 = builder.build();
-    assertEquals(settings13, settings13);
-    assertNotEquals(settings13, null);
-    assertNotEquals(settings13, "a string");
-    assertEquals(settings13.hashCode(), settings13.hashCode());
-
-    UnaryCallSettings.Builder<?, ?> builder5 = new UnaryCallSettings.Builder<Object, Object>();
-    builder5.setSimpleTimeoutNoRetries(Duration.ofSeconds(5));
-
-    UnaryCallSettings<?, ?> settings5 = builder5.build();
-    assertNotEquals(settings13, settings5);
-    assertNotEquals(settings13.hashCode(), settings5.hashCode());
-  }
-
-  @Test
-  public void testEquals_retrySettings() {
-    RetrySettings initialSettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    UnaryCallSettings.Builder<?, ?> builder = new UnaryCallSettings.Builder<Object, Object>();
-    UnaryCallSettings<?, ?> settingsNoRetry = builder.build();
-
-    builder.setRetrySettings(initialSettings);
-    UnaryCallSettings<?, ?> settingsRetry = builder.build();
-
-    assertNotEquals(settingsRetry, settingsNoRetry);
-  }
-
-  @Test
-  public void testEquals_retryableCodes() {
-    UnaryCallSettings.Builder<?, ?> builder = new UnaryCallSettings.Builder<Object, Object>();
-    UnaryCallSettings<?, ?> settingsNoCodes = builder.build();
-
-    builder.setRetryableCodes(StatusCode.Code.CANCELLED);
-    UnaryCallSettings<?, ?> settingsCodes = builder.build();
-
-    assertNotEquals(settingsCodes, settingsNoCodes);
-
-    UnaryCallSettings<?, ?> settingsCodes2 = builder.build();
-    assertEquals(settingsCodes, settingsCodes2);
-  }
-
-  @Test
-  public void testRetrySettingsBuilder() {
-    RetrySettings initialSettings =
-        RetrySettings.newBuilder()
-            .setInitialRetryDelay(Duration.ofMillis(5))
-            .setMaxRetryDelay(Duration.ofSeconds(1))
-            .setRetryDelayMultiplier(2)
-            .setInitialRpcTimeout(Duration.ofMillis(100))
-            .setMaxRpcTimeout(Duration.ofMillis(200))
-            .setRpcTimeoutMultiplier(1.1)
-            .setJittered(true)
-            .setMaxAttempts(10)
-            .build();
-
-    UnaryCallSettings.Builder<Object, Object> builder =
-        new UnaryCallSettings.Builder<Object, Object>().setRetrySettings(initialSettings);
-
-    builder.retrySettings().setMaxRetryDelay(Duration.ofMinutes(1));
-
-    assertThat(builder.getRetrySettings().getMaxRetryDelay()).isEqualTo(Duration.ofMinutes(1));
-    assertThat(builder.build().getRetrySettings().getMaxRetryDelay())
-        .isEqualTo(Duration.ofMinutes(1));
-  }
-
-  @Test
-  public void testToString() {
-    RetrySettings retrySettings = RetrySettings.newBuilder().build();
-    Set<StatusCode.Code> retryableCodes = ImmutableSet.of(StatusCode.Code.DEADLINE_EXCEEDED);
-    UnaryCallSettings<?, ?> unaryCallSettings =
-        UnaryCallSettings.newUnaryCallSettingsBuilder()
-            .setRetrySettings(retrySettings)
-            .setRetryableCodes(retryableCodes)
-            .build();
-    assertThat(unaryCallSettings.toString()).contains("retryableCodes=" + retryableCodes);
-    assertThat(unaryCallSettings.toString()).contains("retrySettings=" + retrySettings);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/UnaryCallableTest.java b/gax/src/test/java/com/google/api/gax/rpc/UnaryCallableTest.java
deleted file mode 100644
index 0e16545d4..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/UnaryCallableTest.java
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2016 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertSame;
-
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeChannel;
-import com.google.api.gax.rpc.testing.FakeSimpleApi.StashCallable;
-import com.google.auth.Credentials;
-import com.google.common.collect.ImmutableSet;
-import java.util.Set;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-/** Tests for {@link UnaryCallable}. */
-@RunWith(JUnit4.class)
-public class UnaryCallableTest {
-
-  @Test
-  public void simpleCall() throws Exception {
-    StashCallable<Integer, Integer> stashCallable = new StashCallable<>(1);
-
-    Integer response = stashCallable.call(2, FakeCallContext.createDefault());
-    assertEquals(Integer.valueOf(1), response);
-    FakeCallContext callContext = (FakeCallContext) stashCallable.getContext();
-    assertNull(callContext.getChannel());
-    assertNull(callContext.getCredentials());
-  }
-
-  @Test
-  public void call() throws Exception {
-    ApiCallContext defaultCallContext = FakeCallContext.createDefault();
-    StashCallable<Integer, Integer> stashCallable = new StashCallable<>(1);
-    UnaryCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(defaultCallContext);
-
-    Integer response = callable.call(2);
-    assertEquals(Integer.valueOf(1), response);
-    assertNotNull(stashCallable.getContext());
-    assertSame(defaultCallContext, stashCallable.getContext());
-  }
-
-  @Test
-  public void callWithContext() throws Exception {
-    FakeChannel channel = new FakeChannel();
-    Credentials credentials = Mockito.mock(Credentials.class);
-    RetrySettings retrySettings = Mockito.mock(RetrySettings.class);
-    Set<StatusCode.Code> retryableCodes =
-        ImmutableSet.of(
-            StatusCode.Code.INTERNAL,
-            StatusCode.Code.UNAVAILABLE,
-            StatusCode.Code.DEADLINE_EXCEEDED);
-    ApiCallContext context =
-        FakeCallContext.createDefault()
-            .withChannel(channel)
-            .withCredentials(credentials)
-            .withRetrySettings(retrySettings)
-            .withRetryableCodes(retryableCodes);
-    StashCallable<Integer, Integer> stashCallable = new StashCallable<>(1);
-    UnaryCallable<Integer, Integer> callable =
-        stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
-
-    Integer response = callable.call(2, context);
-    assertEquals(Integer.valueOf(1), response);
-    FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
-    assertSame(channel, actualContext.getChannel());
-    assertSame(credentials, actualContext.getCredentials());
-    assertSame(retrySettings, actualContext.getRetrySettings());
-    assertThat(actualContext.getRetryableCodes()).containsExactlyElementsIn(retryableCodes);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/WatchdogTest.java b/gax/src/test/java/com/google/api/gax/rpc/WatchdogTest.java
deleted file mode 100644
index e20218452..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/WatchdogTest.java
+++ /dev/null
@@ -1,313 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.FakeApiClock;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCall;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCallable;
-import com.google.common.collect.Queues;
-import java.util.Queue;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class WatchdogTest {
-  private static final ScheduledExecutorService EXECUTOR = Executors.newScheduledThreadPool(1);
-
-  private FakeApiClock clock;
-  private final Duration checkInterval = Duration.ofMillis(1000);
-  private Duration waitTime = Duration.ofSeconds(10);
-  private Duration idleTime = Duration.ofMinutes(5);
-
-  private Watchdog watchdog;
-  private MockServerStreamingCallable<String, String> callable;
-  private AccumulatingObserver<String> innerObserver;
-  private MockServerStreamingCall<String, String> call;
-
-  @Before
-  public void setUp() {
-    clock = new FakeApiClock(0);
-    watchdog = Watchdog.create(clock, checkInterval, EXECUTOR);
-
-    callable = new MockServerStreamingCallable<>();
-    innerObserver = new AccumulatingObserver<>();
-    callable.call("request", watchdog.watch(innerObserver, waitTime, idleTime));
-    call = callable.popLastCall();
-  }
-
-  @Test
-  public void testRequestPassthrough() throws Exception {
-    innerObserver.controller.get().request(1);
-    assertThat(call.getController().popLastPull()).isEqualTo(1);
-  }
-
-  @Test
-  public void testWaitTimeout() throws Exception {
-    innerObserver.controller.get(1, TimeUnit.MILLISECONDS).request(1);
-
-    clock.incrementNanoTime(waitTime.toNanos() - 1);
-    watchdog.run();
-    assertThat(call.getController().isCancelled()).isFalse();
-
-    clock.incrementNanoTime(1);
-    watchdog.run();
-    assertThat(call.getController().isCancelled()).isTrue();
-    call.getController()
-        .getObserver()
-        .onError(new RuntimeException("Some upstream exception representing cancellation"));
-
-    Throwable actualError = null;
-    try {
-      innerObserver.done.get();
-    } catch (ExecutionException t) {
-      actualError = t.getCause();
-    }
-    assertThat(actualError).isInstanceOf(WatchdogTimeoutException.class);
-  }
-
-  @Test
-  public void testIdleTimeout() throws InterruptedException {
-    clock.incrementNanoTime(idleTime.toNanos() - 1);
-    watchdog.run();
-    assertThat(call.getController().isCancelled()).isFalse();
-
-    clock.incrementNanoTime(1);
-    watchdog.run();
-    assertThat(call.getController().isCancelled()).isTrue();
-    call.getController()
-        .getObserver()
-        .onError(new RuntimeException("Some upstream exception representing cancellation"));
-
-    Throwable actualError = null;
-    try {
-      innerObserver.done.get();
-    } catch (ExecutionException t) {
-      actualError = t.getCause();
-    }
-    assertThat(actualError).isInstanceOf(WatchdogTimeoutException.class);
-  }
-
-  @Test
-  public void testTimedOutBeforeStart() throws InterruptedException {
-    MockServerStreamingCallable<String, String> callable1 = new MockServerStreamingCallable<>();
-    AccumulatingObserver<String> downstreamObserver1 = new AccumulatingObserver<>();
-    ResponseObserver observer = watchdog.watch(downstreamObserver1, waitTime, idleTime);
-    clock.incrementNanoTime(idleTime.toNanos() + 1);
-    // This should not remove callable1 from watched list
-    watchdog.run();
-    assertThat(downstreamObserver1.done.isDone()).isFalse();
-
-    callable1.call("request", observer);
-    // This should cancel callable1
-    watchdog.run();
-    MockServerStreamingCall<String, String> call1 = callable1.popLastCall();
-    assertThat(call1.getController().isCancelled()).isTrue();
-    call1.getController().getObserver().onError(new CancellationException("User cancelled"));
-    Throwable error = null;
-    try {
-      downstreamObserver1.done.get();
-    } catch (ExecutionException t) {
-      error = t.getCause();
-    }
-    assertThat(error).isInstanceOf(WatchdogTimeoutException.class);
-  }
-
-  @Test
-  public void testMultiple() throws Exception {
-    // Start stream1
-    AccumulatingObserver<String> downstreamObserver1 = new AccumulatingObserver<>();
-    callable.call("request", watchdog.watch(downstreamObserver1, waitTime, idleTime));
-    MockServerStreamingCall<String, String> call1 = callable.popLastCall();
-    downstreamObserver1.controller.get().request(1);
-
-    // Start stream2
-    AccumulatingObserver<String> downstreamObserver2 = new AccumulatingObserver<>();
-    callable.call("req2", watchdog.watch(downstreamObserver2, waitTime, idleTime));
-    MockServerStreamingCall<String, String> call2 = callable.popLastCall();
-    downstreamObserver2.controller.get().request(1);
-
-    // Give stream1 a response at the last possible moment
-    clock.incrementNanoTime(waitTime.toNanos());
-    call1.getController().getObserver().onResponse("resp1");
-
-    // run the callable
-    watchdog.run();
-
-    // Call1 should be ok
-    assertThat(call1.getController().isCancelled()).isFalse();
-    // Should not throw
-    assertThat(downstreamObserver1.done.isDone()).isFalse();
-
-    // Call2 should be timed out
-    assertThat(call2.getController().isCancelled()).isTrue();
-    call2.getController().getObserver().onError(new CancellationException("User cancelled"));
-    Throwable error = null;
-    try {
-      downstreamObserver2.done.get();
-    } catch (ExecutionException t) {
-      error = t.getCause();
-    }
-    assertThat(error).isInstanceOf(WatchdogTimeoutException.class);
-  }
-
-  @Test
-  @SuppressWarnings("unchecked")
-  public void testWatchdogBeingClosed() {
-    ScheduledFuture future = Mockito.mock(ScheduledFuture.class);
-    ScheduledExecutorService mockExecutor = getMockExecutorService(future);
-    Watchdog underTest = Watchdog.create(clock, checkInterval, mockExecutor);
-    assertThat(underTest).isInstanceOf(BackgroundResource.class);
-
-    underTest.close();
-    underTest.shutdown();
-
-    Mockito.verify(mockExecutor)
-        .scheduleAtFixedRate(
-            underTest, checkInterval.toMillis(), checkInterval.toMillis(), TimeUnit.MILLISECONDS);
-    Mockito.verify(future, Mockito.times(2)).cancel(false);
-
-    underTest.shutdownNow();
-    Mockito.verify(future).cancel(true);
-    Mockito.verifyNoMoreInteractions(mockExecutor);
-  }
-
-  @Test
-  public void awaitTermination_shouldReturnTrueIfFutureIsDone() throws Exception {
-    int duration = 1000;
-    TimeUnit timeUnit = TimeUnit.MILLISECONDS;
-    ScheduledFuture future = Mockito.mock(ScheduledFuture.class);
-    ScheduledExecutorService mockExecutor = getMockExecutorService(future);
-    Watchdog watchdog = Watchdog.create(clock, checkInterval, mockExecutor);
-    watchdog.shutdown();
-
-    boolean actual = watchdog.awaitTermination(duration, timeUnit);
-
-    assertThat(actual).isTrue();
-  }
-
-  @Test
-  public void awaitTermination_shouldReturnFalseIfGettingFutureTimedOut() throws Exception {
-    int duration = 1000;
-    TimeUnit timeUnit = TimeUnit.MILLISECONDS;
-    ScheduledFuture future = Mockito.mock(ScheduledFuture.class);
-    Mockito.doThrow(new TimeoutException()).when(future).get(duration, timeUnit);
-    ScheduledExecutorService mockExecutor = getMockExecutorService(future);
-    Watchdog watchdog = Watchdog.create(clock, checkInterval, mockExecutor);
-
-    boolean actual = watchdog.awaitTermination(duration, timeUnit);
-
-    assertThat(actual).isFalse();
-  }
-
-  @Test
-  public void awaitTermination_shouldReturnTrueIfFutureIsAlreadyCancelled() throws Exception {
-    int duration = 1000;
-    TimeUnit timeUnit = TimeUnit.MILLISECONDS;
-    ScheduledFuture future = Mockito.mock(ScheduledFuture.class);
-    Mockito.doThrow(new CancellationException()).when(future).get(duration, timeUnit);
-    ScheduledExecutorService mockExecutor = getMockExecutorService(future);
-    Watchdog watchdog = Watchdog.create(clock, checkInterval, mockExecutor);
-
-    boolean actual = watchdog.awaitTermination(duration, timeUnit);
-
-    assertThat(actual).isTrue();
-  }
-
-  @Test
-  public void awaitTermination_shouldReturnFalseIfGettingFutureThrowsExecutionException()
-      throws Exception {
-    int duration = 1000;
-    TimeUnit timeUnit = TimeUnit.MILLISECONDS;
-    ScheduledFuture future = Mockito.mock(ScheduledFuture.class);
-    Mockito.doThrow(new ExecutionException(new RuntimeException()))
-        .when(future)
-        .get(duration, timeUnit);
-    ScheduledExecutorService mockExecutor = getMockExecutorService(future);
-    Watchdog watchdog = Watchdog.create(clock, checkInterval, mockExecutor);
-
-    boolean actual = watchdog.awaitTermination(duration, timeUnit);
-
-    assertThat(actual).isTrue();
-  }
-
-  private ScheduledExecutorService getMockExecutorService(ScheduledFuture future) {
-    ScheduledExecutorService mockExecutor = Mockito.mock(ScheduledExecutorService.class);
-    Mockito.when(
-            mockExecutor.scheduleAtFixedRate(
-                Mockito.any(Watchdog.class),
-                Mockito.anyLong(),
-                Mockito.anyLong(),
-                Mockito.any(TimeUnit.class)))
-        .thenReturn(future);
-    return mockExecutor;
-  }
-
-  static class AccumulatingObserver<T> implements ResponseObserver<T> {
-    SettableApiFuture<StreamController> controller = SettableApiFuture.create();
-    Queue<T> responses = Queues.newLinkedBlockingDeque();
-    SettableApiFuture<Void> done = SettableApiFuture.create();
-
-    @Override
-    public void onStart(StreamController controller) {
-      controller.disableAutoInboundFlowControl();
-      this.controller.set(controller);
-    }
-
-    @Override
-    public void onResponse(T response) {
-      responses.add(response);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      done.setException(t);
-    }
-
-    @Override
-    public void onComplete() {
-      done.set(null);
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/internal/ApiCallContextOptionsTest.java b/gax/src/test/java/com/google/api/gax/rpc/internal/ApiCallContextOptionsTest.java
deleted file mode 100644
index cf4f785bb..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/internal/ApiCallContextOptionsTest.java
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.internal;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class ApiCallContextOptionsTest {
-
-  private static final ApiCallContext.Key<Integer> INTEGER_KEY = ApiCallContext.Key.create("key1");
-  private static final ApiCallContext.Key<String> STRING_KEY = ApiCallContext.Key.create("key2");
-  private static final ApiCallContext.Key<Double> DOUBLE_KEY = ApiCallContext.Key.create("key3");
-
-  @Test
-  public void testWithOption() {
-    ApiCallContextOptions options =
-        ApiCallContextOptions.getDefaultOptions()
-            .withOption(INTEGER_KEY, 1)
-            .withOption(STRING_KEY, "test")
-            .withOption(DOUBLE_KEY, 2.0);
-    assertThat(options.getOption(INTEGER_KEY)).isEqualTo(1);
-    assertThat(options.getOption(STRING_KEY)).isEqualTo("test");
-    assertThat(options.getOption(DOUBLE_KEY)).isEqualTo(2.0);
-
-    ApiCallContextOptions updatedOptions = options.withOption(INTEGER_KEY, 10);
-    assertThat(updatedOptions.getOption(INTEGER_KEY)).isEqualTo(10);
-    assertThat(options.getOption(STRING_KEY)).isEqualTo("test");
-    assertThat(options.getOption(DOUBLE_KEY)).isEqualTo(2.0);
-  }
-
-  @Test
-  public void testMergeEmpty() {
-    ApiCallContextOptions options =
-        ApiCallContextOptions.getDefaultOptions()
-            .withOption(INTEGER_KEY, 1)
-            .withOption(STRING_KEY, "test");
-
-    ApiCallContextOptions defaultOptions = ApiCallContextOptions.getDefaultOptions();
-
-    ApiCallContextOptions mergedOptions1 = options.merge(defaultOptions);
-    assertThat(mergedOptions1.getOption(INTEGER_KEY)).isEqualTo(1);
-    assertThat(mergedOptions1.getOption(STRING_KEY)).isEqualTo("test");
-
-    ApiCallContextOptions mergedOptions2 = defaultOptions.merge(options);
-    assertThat(mergedOptions2.getOption(INTEGER_KEY)).isEqualTo(1);
-    assertThat(mergedOptions2.getOption(STRING_KEY)).isEqualTo("test");
-  }
-
-  @Test
-  public void testMergeDifferentKeys() {
-    ApiCallContextOptions options1 =
-        ApiCallContextOptions.getDefaultOptions()
-            .withOption(INTEGER_KEY, 1)
-            .withOption(STRING_KEY, "test");
-    ApiCallContextOptions options2 =
-        ApiCallContextOptions.getDefaultOptions().withOption(DOUBLE_KEY, 5.0);
-    ApiCallContextOptions mergedOptions = options1.merge(options2);
-    assertThat(mergedOptions.getOption(INTEGER_KEY)).isEqualTo(1);
-    assertThat(mergedOptions.getOption(STRING_KEY)).isEqualTo("test");
-    assertThat(mergedOptions.getOption(DOUBLE_KEY)).isEqualTo(5.0);
-  }
-
-  @Test
-  public void testMergeDuplicateKeys() {
-    ApiCallContextOptions options1 =
-        ApiCallContextOptions.getDefaultOptions()
-            .withOption(INTEGER_KEY, 1)
-            .withOption(STRING_KEY, "test");
-    ApiCallContextOptions options2 =
-        ApiCallContextOptions.getDefaultOptions()
-            .withOption(STRING_KEY, "newTest")
-            .withOption(DOUBLE_KEY, 5.0);
-    ApiCallContextOptions mergedOptions = options1.merge(options2);
-    assertThat(mergedOptions.getOption(INTEGER_KEY)).isEqualTo(1);
-    assertThat(mergedOptions.getOption(STRING_KEY)).isEqualTo("newTest");
-    assertThat(mergedOptions.getOption(DOUBLE_KEY)).isEqualTo(5.0);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/internal/HeadersTest.java b/gax/src/test/java/com/google/api/gax/rpc/internal/HeadersTest.java
deleted file mode 100644
index ebcb9bd39..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/internal/HeadersTest.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.internal;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class HeadersTest {
-
-  @Test
-  public void testMergeHeaders() {
-    Map<String, List<String>> headers1 = createHeaders("key1", "value1", "key1", "value2");
-    Map<String, List<String>> headers2 = createHeaders("key1", "value2", "key2", "value2");
-    Map<String, List<String>> mergedHeaders = Headers.mergeHeaders(headers1, headers2);
-    Map<String, List<String>> expectedHeaders =
-        createHeaders("key1", "value1", "key1", "value2", "key1", "value2", "key2", "value2");
-    assertThat(mergedHeaders).containsExactlyEntriesIn(expectedHeaders);
-  }
-
-  @Test
-  public void testMergeHeadersEmpty() {
-    Map<String, List<String>> headers1 = createHeaders();
-    Map<String, List<String>> headers2 = createHeaders("key1", "value1", "key2", "value2");
-    Map<String, List<String>> mergedHeaders = Headers.mergeHeaders(headers1, headers2);
-    Map<String, List<String>> expectedHeaders = createHeaders("key1", "value1", "key2", "value2");
-    assertThat(mergedHeaders).containsExactlyEntriesIn(expectedHeaders);
-  }
-
-  private static Map<String, List<String>> createHeaders(String... keyValues) {
-    Map<String, List<String>> headers = new HashMap<>();
-    for (int i = 0; i < keyValues.length; i += 2) {
-      String key = keyValues[i];
-      String value = keyValues[i + 1];
-      if (!headers.containsKey(key)) {
-        headers.put(key, new ArrayList<String>());
-      }
-      headers.get(key).add(value);
-    }
-    return headers;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentialsTest.java b/gax/src/test/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentialsTest.java
deleted file mode 100644
index af36e0a5b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/internal/QuotaProjectIdHidingCredentialsTest.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2020 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.internal;
-
-import com.google.auth.Credentials;
-import com.google.auth.oauth2.GoogleCredentials;
-import com.google.common.collect.ImmutableMap;
-import java.io.IOException;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mockito;
-
-@RunWith(JUnit4.class)
-public class QuotaProjectIdHidingCredentialsTest {
-  private static final String QUOTA_PROJECT_ID_KEY = "x-goog-user-project";
-  private static final String QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE =
-      "quota_project_id_from_credentials";
-
-  @Test
-  public void quotaProjectIdHidingCredentials_getRequestMetadata() throws IOException {
-    // Credentials with quota project id
-    Map<String, List<String>> metaDataWithQuota =
-        ImmutableMap.of(
-            "k1",
-            Collections.singletonList("v1"),
-            QUOTA_PROJECT_ID_KEY,
-            Collections.singletonList(QUOTA_PROJECT_ID_FROM_CREDENTIALS_VALUE));
-    Credentials credentialsWithQuotaProjectId = Mockito.mock(GoogleCredentials.class);
-    Mockito.when(credentialsWithQuotaProjectId.getRequestMetadata(null))
-        .thenReturn(metaDataWithQuota);
-    QuotaProjectIdHidingCredentials quotaProjectIdHidingCredentials =
-        new QuotaProjectIdHidingCredentials(credentialsWithQuotaProjectId);
-    Map<String, List<String>> metaDataHidingQuota =
-        quotaProjectIdHidingCredentials.getRequestMetadata();
-
-    Assert.assertTrue(metaDataWithQuota.containsKey(QUOTA_PROJECT_ID_KEY));
-    Assert.assertFalse(metaDataHidingQuota.containsKey(QUOTA_PROJECT_ID_KEY));
-    Assert.assertEquals(metaDataWithQuota.size() - 1, metaDataHidingQuota.size());
-
-    // Credentials without quota project id
-    Map<String, List<String>> metaDataWithoutQuota =
-        ImmutableMap.of("k1", Collections.singletonList("v1"));
-    Credentials credentialsWithoutQuotaProjectId = Mockito.mock(GoogleCredentials.class);
-    Mockito.when(credentialsWithoutQuotaProjectId.getRequestMetadata(null))
-        .thenReturn(metaDataWithoutQuota);
-    QuotaProjectIdHidingCredentials quotaProjectIdHidingCredentialsWithout =
-        new QuotaProjectIdHidingCredentials(credentialsWithoutQuotaProjectId);
-    Map<String, List<String>> metaDataHidingQuotaWithout =
-        quotaProjectIdHidingCredentials.getRequestMetadata();
-
-    Assert.assertEquals(
-        quotaProjectIdHidingCredentialsWithout.getRequestMetadata(), metaDataWithoutQuota);
-  }
-
-  @Test
-  public void quotaProjectIdHidingCredentials_getAuthenticationType() throws IOException {
-    final String mockType = "mock_type";
-    Credentials credentials = Mockito.mock(GoogleCredentials.class);
-    Mockito.when(credentials.getAuthenticationType()).thenReturn(mockType);
-    Mockito.when(credentials.hasRequestMetadata()).thenReturn(true);
-    Mockito.when(credentials.hasRequestMetadataOnly()).thenReturn(false);
-
-    QuotaProjectIdHidingCredentials quotaProjectIdHidingCredentials =
-        new QuotaProjectIdHidingCredentials(credentials);
-    quotaProjectIdHidingCredentials.refresh();
-
-    Assert.assertEquals(quotaProjectIdHidingCredentials.getAuthenticationType(), mockType);
-    Assert.assertTrue(quotaProjectIdHidingCredentials.hasRequestMetadata());
-    Assert.assertFalse(quotaProjectIdHidingCredentials.hasRequestMetadataOnly());
-
-    Mockito.verify(credentials, Mockito.atLeastOnce()).refresh();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/mtls/AbstractMtlsTransportChannelTest.java b/gax/src/test/java/com/google/api/gax/rpc/mtls/AbstractMtlsTransportChannelTest.java
deleted file mode 100644
index a75c7b812..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/mtls/AbstractMtlsTransportChannelTest.java
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.mtls;
-
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-import com.google.api.gax.rpc.mtls.MtlsProvider.MtlsEndpointUsagePolicy;
-import com.google.api.gax.rpc.testing.FakeMtlsProvider;
-import java.io.IOException;
-import java.security.GeneralSecurityException;
-import org.junit.Test;
-
-public abstract class AbstractMtlsTransportChannelTest {
-  /**
-   * Returns the mTLS object from the created transport channel. mTLS object is created with mTLS
-   * keystore. For HttpJsonTransportChannel, the mTLS object is the SslContext; for
-   * GrpcTransportChannel, the mTLS object is the ChannelCredentials. The transport channel is mTLS
-   * if and only if the related mTLS object is not null.
-   */
-  protected abstract Object getMtlsObjectFromTransportChannel(MtlsProvider provider)
-      throws IOException, GeneralSecurityException;
-
-  @Test
-  public void testNotUseClientCertificate() throws IOException, GeneralSecurityException {
-    MtlsProvider provider =
-        new FakeMtlsProvider(false, MtlsEndpointUsagePolicy.AUTO, null, "", false);
-    assertNull(getMtlsObjectFromTransportChannel(provider));
-  }
-
-  @Test
-  public void testUseClientCertificate() throws IOException, GeneralSecurityException {
-    MtlsProvider provider =
-        new FakeMtlsProvider(
-            true,
-            MtlsEndpointUsagePolicy.AUTO,
-            FakeMtlsProvider.createTestMtlsKeyStore(),
-            "",
-            false);
-    assertNotNull(getMtlsObjectFromTransportChannel(provider));
-  }
-
-  @Test
-  public void testNoClientCertificate() throws IOException, GeneralSecurityException {
-    MtlsProvider provider =
-        new FakeMtlsProvider(true, MtlsEndpointUsagePolicy.AUTO, null, "", false);
-    assertNull(getMtlsObjectFromTransportChannel(provider));
-  }
-
-  @Test
-  public void testGetKeyStoreThrows() throws GeneralSecurityException {
-    // Test the case where provider.getKeyStore() throws.
-    MtlsProvider provider =
-        new FakeMtlsProvider(true, MtlsEndpointUsagePolicy.AUTO, null, "", true);
-    try {
-      getMtlsObjectFromTransportChannel(provider);
-      fail("should throw an exception");
-    } catch (IOException e) {
-      assertTrue(
-          "expected getKeyStore to throw an exception",
-          e.getMessage().contains("getKeyStore throws exception"));
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/mtls/MtlsProviderTest.java b/gax/src/test/java/com/google/api/gax/rpc/mtls/MtlsProviderTest.java
deleted file mode 100644
index 49be7aab5..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/mtls/MtlsProviderTest.java
+++ /dev/null
@@ -1,215 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.mtls;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.security.GeneralSecurityException;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-@RunWith(JUnit4.class)
-public class MtlsProviderTest {
-  private static class TestCertProviderCommandProcess extends Process {
-    private boolean runForever;
-    private int exitValue;
-
-    public TestCertProviderCommandProcess(int exitValue, boolean runForever) {
-      this.runForever = runForever;
-      this.exitValue = exitValue;
-    }
-
-    @Override
-    public OutputStream getOutputStream() {
-      return null;
-    }
-
-    @Override
-    public InputStream getInputStream() {
-      return null;
-    }
-
-    @Override
-    public InputStream getErrorStream() {
-      return null;
-    }
-
-    @Override
-    public int waitFor() throws InterruptedException {
-      return 0;
-    }
-
-    @Override
-    public int exitValue() {
-      if (runForever) {
-        throw new IllegalThreadStateException();
-      }
-      return exitValue;
-    }
-
-    @Override
-    public void destroy() {}
-  }
-
-  static class TestProcessProvider implements MtlsProvider.ProcessProvider {
-    private int exitCode;
-
-    public TestProcessProvider(int exitCode) {
-      this.exitCode = exitCode;
-    }
-
-    @Override
-    public Process createProcess(InputStream metadata) throws IOException {
-      return new TestCertProviderCommandProcess(exitCode, false);
-    }
-  }
-
-  @Test
-  public void testUseMtlsEndpointAlways() {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "always" : "false",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertEquals(
-        MtlsProvider.MtlsEndpointUsagePolicy.ALWAYS, mtlsProvider.getMtlsEndpointUsagePolicy());
-  }
-
-  @Test
-  public void testUseMtlsEndpointAuto() {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "auto" : "false",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertEquals(
-        MtlsProvider.MtlsEndpointUsagePolicy.AUTO, mtlsProvider.getMtlsEndpointUsagePolicy());
-  }
-
-  @Test
-  public void testUseMtlsEndpointNever() {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "never" : "false",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertEquals(
-        MtlsProvider.MtlsEndpointUsagePolicy.NEVER, mtlsProvider.getMtlsEndpointUsagePolicy());
-  }
-
-  @Test
-  public void testUseMtlsClientCertificateTrue() {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "auto" : "true",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertTrue(mtlsProvider.useMtlsClientCertificate());
-  }
-
-  @Test
-  public void testUseMtlsClientCertificateFalse() {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "auto" : "false",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertFalse(mtlsProvider.useMtlsClientCertificate());
-  }
-
-  @Test
-  public void testGetKeyStore() throws IOException {
-    MtlsProvider mtlsProvider =
-        new MtlsProvider(
-            name -> name.equals("GOOGLE_API_USE_MTLS_ENDPOINT") ? "always" : "false",
-            new TestProcessProvider(0),
-            "/path/to/missing/file");
-    assertNull(mtlsProvider.getKeyStore());
-  }
-
-  @Test
-  public void testGetKeyStoreNonZeroExitCode()
-      throws IOException, InterruptedException, GeneralSecurityException {
-    try {
-      InputStream metadata =
-          this.getClass()
-              .getClassLoader()
-              .getResourceAsStream("com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem");
-      MtlsProvider.getKeyStore(metadata, new TestProcessProvider(1));
-      fail("should throw an exception");
-    } catch (IOException e) {
-      assertTrue(
-          "expected to fail with nonzero exit code",
-          e.getMessage().contains("Cert provider command failed with exit code: 1"));
-    }
-  }
-
-  @Test
-  public void testExtractCertificateProviderCommand() throws IOException {
-    InputStream inputStream =
-        this.getClass()
-            .getClassLoader()
-            .getResourceAsStream("com/google/api/gax/rpc/mtls/mtls_context_aware_metadata.json");
-    List<String> command = MtlsProvider.extractCertificateProviderCommand(inputStream);
-    assertEquals(2, command.size());
-    assertEquals("some_binary", command.get(0));
-    assertEquals("some_argument", command.get(1));
-  }
-
-  @Test
-  public void testRunCertificateProviderCommandSuccess() throws IOException, InterruptedException {
-    Process certCommandProcess = new TestCertProviderCommandProcess(0, false);
-    int exitValue = MtlsProvider.runCertificateProviderCommand(certCommandProcess, 100);
-    assertEquals(0, exitValue);
-  }
-
-  @Test
-  public void testRunCertificateProviderCommandTimeout() throws InterruptedException {
-    Process certCommandProcess = new TestCertProviderCommandProcess(0, true);
-    try {
-      MtlsProvider.runCertificateProviderCommand(certCommandProcess, 100);
-      fail("should throw an exception");
-    } catch (IOException e) {
-      assertTrue(
-          "expected to fail with timeout",
-          e.getMessage().contains("cert provider command timed out"));
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeApiException.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeApiException.java
deleted file mode 100644
index e76b9fafb..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeApiException.java
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiException;
-
-@InternalApi("for testing")
-public class FakeApiException extends ApiException {
-
-  @BetaApi
-  public FakeApiException(Throwable cause, FakeStatusCode.Code statusCode, boolean retryable) {
-    super(cause, FakeStatusCode.of(statusCode), retryable);
-  }
-
-  @BetaApi
-  public FakeApiException(
-      String message, Throwable cause, FakeStatusCode.Code statusCode, boolean retryable) {
-    super(message, cause, FakeStatusCode.of(statusCode), retryable);
-  }
-
-  /**
-   * Returns the status code of the underlying exception. In cases where the underlying status code
-   * can't be determined, the status code will be FakeStatusCode.Code.UNKNOWN.
-   */
-  public FakeStatusCode getStatusCode() {
-    return (FakeStatusCode) super.getStatusCode();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeBatchableApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeBatchableApi.java
deleted file mode 100644
index 525815f34..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeBatchableApi.java
+++ /dev/null
@@ -1,226 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.batching.BatchEntry;
-import com.google.api.gax.batching.BatchingRequestBuilder;
-import com.google.api.gax.batching.PartitionKey;
-import com.google.api.gax.batching.RequestBuilder;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BatchedRequestIssuer;
-import com.google.api.gax.rpc.BatchingDescriptor;
-import com.google.api.gax.rpc.UnaryCallable;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.List;
-
-@InternalApi("for testing")
-public class FakeBatchableApi {
-
-  public static class LabeledIntList {
-    public String label;
-    public List<Integer> ints;
-
-    public LabeledIntList(String label, Integer... numbers) {
-      this(label, new ArrayList<>(Arrays.asList(numbers)));
-    }
-
-    public LabeledIntList(String label, List<Integer> ints) {
-      this.label = label;
-      this.ints = ints;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-      if (this == o) {
-        return true;
-      }
-      if (o == null || getClass() != o.getClass()) {
-        return false;
-      }
-
-      LabeledIntList that = (LabeledIntList) o;
-
-      if (!label.equals(that.label)) {
-        return false;
-      }
-      return ints.equals(that.ints);
-    }
-
-    @Override
-    public int hashCode() {
-      int result = label.hashCode();
-      result = 31 * result + ints.hashCode();
-      return result;
-    }
-
-    public LabeledIntList clone() {
-      return new LabeledIntList(this.label, new ArrayList<>(this.ints));
-    }
-  }
-
-  public static LabeledIntSquarerCallable callLabeledIntSquarer = new LabeledIntSquarerCallable();
-
-  public static class LabeledIntSquarerCallable
-      extends UnaryCallable<LabeledIntList, List<Integer>> {
-
-    @Override
-    public ApiFuture<List<Integer>> futureCall(LabeledIntList request, ApiCallContext context) {
-      List<Integer> result = new ArrayList<>();
-      for (Integer i : request.ints) {
-        result.add(i * i);
-      }
-      return ApiFutures.immediateFuture(result);
-    }
-  }
-
-  public static SquarerBatchingDescriptor SQUARER_BATCHING_DESC = new SquarerBatchingDescriptor();
-
-  public static class SquarerBatchingDescriptor
-      implements BatchingDescriptor<LabeledIntList, List<Integer>> {
-
-    @Override
-    public PartitionKey getBatchPartitionKey(LabeledIntList request) {
-      return new PartitionKey(request.label);
-    }
-
-    @Override
-    public RequestBuilder<LabeledIntList> getRequestBuilder() {
-      return new RequestBuilder<LabeledIntList>() {
-
-        LabeledIntList list;
-
-        @Override
-        public void appendRequest(LabeledIntList request) {
-          if (list == null) {
-            list = request;
-          } else {
-            list.ints.addAll(request.ints);
-          }
-        }
-
-        @Override
-        public LabeledIntList build() {
-          return list;
-        }
-      };
-    }
-
-    @Override
-    public void splitResponse(
-        List<Integer> batchResponse,
-        Collection<? extends BatchedRequestIssuer<List<Integer>>> batch) {
-      int batchMessageIndex = 0;
-      for (BatchedRequestIssuer<List<Integer>> responder : batch) {
-        List<Integer> messageIds = new ArrayList<>();
-        long messageCount = responder.getMessageCount();
-        for (int i = 0; i < messageCount; i++) {
-          messageIds.add(batchResponse.get(batchMessageIndex));
-          batchMessageIndex += 1;
-        }
-        responder.setResponse(messageIds);
-      }
-    }
-
-    @Override
-    public void splitException(
-        Throwable throwable, Collection<? extends BatchedRequestIssuer<List<Integer>>> batch) {
-      for (BatchedRequestIssuer<List<Integer>> responder : batch) {
-        responder.setException(throwable);
-      }
-    }
-
-    @Override
-    public long countElements(LabeledIntList request) {
-      return request.ints.size();
-    }
-
-    @Override
-    public long countBytes(LabeledIntList request) {
-      long counter = 0;
-      for (Integer i : request.ints) {
-        counter += i;
-      }
-      // Limit the byte size to simulate merged messages having smaller serialized size than the sum
-      // of their components.
-      return Math.min(counter, 5);
-    }
-  }
-
-  public static SquarerBatchingDescriptorV2 SQUARER_BATCHING_DESC_V2 =
-      new SquarerBatchingDescriptorV2();
-
-  public static class SquarerBatchingDescriptorV2
-      implements com.google.api.gax.batching.BatchingDescriptor<
-          Integer, Integer, LabeledIntList, List<Integer>> {
-
-    @Override
-    public BatchingRequestBuilder<Integer, LabeledIntList> newRequestBuilder(
-        final LabeledIntList prototype) {
-      return new BatchingRequestBuilder<Integer, LabeledIntList>() {
-        final LabeledIntList labelList = prototype.clone();
-
-        @Override
-        public void add(Integer element) {
-          labelList.ints.add(element);
-        }
-
-        @Override
-        public LabeledIntList build() {
-          return labelList;
-        }
-      };
-    }
-
-    @Override
-    public void splitResponse(
-        List<Integer> batchResponse, List<BatchEntry<Integer, Integer>> batch) {
-      for (int i = 0; i < batchResponse.size(); i++) {
-        batch.get(i).getResultFuture().set(batchResponse.get(i));
-      }
-    }
-
-    @Override
-    public void splitException(Throwable throwable, List<BatchEntry<Integer, Integer>> batch) {
-      for (BatchEntry<Integer, Integer> entry : batch) {
-        entry.getResultFuture().setException(throwable);
-      }
-    }
-
-    @Override
-    public long countBytes(Integer element) {
-      return 1;
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallContext.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallContext.java
deleted file mode 100644
index 84d40e11c..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallContext.java
+++ /dev/null
@@ -1,425 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.retrying.RetrySettings;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.TransportChannel;
-import com.google.api.gax.rpc.internal.ApiCallContextOptions;
-import com.google.api.gax.rpc.internal.Headers;
-import com.google.api.gax.tracing.ApiTracer;
-import com.google.api.gax.tracing.BaseApiTracer;
-import com.google.auth.Credentials;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.ImmutableSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.threeten.bp.Duration;
-
-@InternalApi("for testing")
-public class FakeCallContext implements ApiCallContext {
-  private final Credentials credentials;
-  private final FakeChannel channel;
-  private final Duration timeout;
-  private final Duration streamWaitTimeout;
-  private final Duration streamIdleTimeout;
-  private final ImmutableMap<String, List<String>> extraHeaders;
-  private final ApiCallContextOptions options;
-  private final ApiTracer tracer;
-  private final RetrySettings retrySettings;
-  private final ImmutableSet<StatusCode.Code> retryableCodes;
-
-  private FakeCallContext(
-      Credentials credentials,
-      FakeChannel channel,
-      Duration timeout,
-      Duration streamWaitTimeout,
-      Duration streamIdleTimeout,
-      ImmutableMap<String, List<String>> extraHeaders,
-      ApiCallContextOptions options,
-      ApiTracer tracer,
-      RetrySettings retrySettings,
-      Set<StatusCode.Code> retryableCodes) {
-    this.credentials = credentials;
-    this.channel = channel;
-    this.timeout = timeout;
-    this.streamWaitTimeout = streamWaitTimeout;
-    this.streamIdleTimeout = streamIdleTimeout;
-    this.extraHeaders = extraHeaders;
-    this.options = options;
-    this.tracer = tracer;
-    this.retrySettings = retrySettings;
-    this.retryableCodes = retryableCodes == null ? null : ImmutableSet.copyOf(retryableCodes);
-  }
-
-  public static FakeCallContext createDefault() {
-    return new FakeCallContext(
-        null,
-        null,
-        null,
-        null,
-        null,
-        ImmutableMap.<String, List<String>>of(),
-        ApiCallContextOptions.getDefaultOptions(),
-        null,
-        null,
-        null);
-  }
-
-  @Override
-  public FakeCallContext nullToSelf(ApiCallContext inputContext) {
-    FakeCallContext fakeCallContext;
-    if (inputContext == null) {
-      fakeCallContext = this;
-    } else {
-      if (!(inputContext instanceof FakeCallContext)) {
-        throw new IllegalArgumentException(
-            "context must be an instance of FakeCallContext, but found "
-                + inputContext.getClass().getName());
-      }
-      fakeCallContext = (FakeCallContext) inputContext;
-    }
-    return fakeCallContext;
-  }
-
-  @Override
-  public ApiCallContext merge(ApiCallContext inputCallContext) {
-    if (inputCallContext == null) {
-      return this;
-    }
-    if (!(inputCallContext instanceof FakeCallContext)) {
-      throw new IllegalArgumentException(
-          "context must be an instance of FakeCallContext, but found "
-              + inputCallContext.getClass().getName());
-    }
-    FakeCallContext fakeCallContext = (FakeCallContext) inputCallContext;
-
-    FakeChannel newChannel = fakeCallContext.channel;
-    if (newChannel == null) {
-      newChannel = channel;
-    }
-
-    Credentials newCallCredentials = fakeCallContext.credentials;
-    if (newCallCredentials == null) {
-      newCallCredentials = credentials;
-    }
-
-    Duration newTimeout = fakeCallContext.timeout;
-    if (newTimeout == null) {
-      newTimeout = timeout;
-    }
-
-    Duration newStreamWaitTimeout = fakeCallContext.streamWaitTimeout;
-    if (newStreamWaitTimeout == null) {
-      newStreamWaitTimeout = streamWaitTimeout;
-    }
-
-    Duration newStreamIdleTimeout = fakeCallContext.streamIdleTimeout;
-    if (newStreamIdleTimeout == null) {
-      newStreamIdleTimeout = streamIdleTimeout;
-    }
-
-    ApiTracer newTracer = fakeCallContext.tracer;
-    if (newTracer == null) {
-      newTracer = this.tracer;
-    }
-
-    RetrySettings newRetrySettings = fakeCallContext.retrySettings;
-    if (newRetrySettings == null) {
-      newRetrySettings = this.retrySettings;
-    }
-
-    Set<StatusCode.Code> newRetryableCodes = fakeCallContext.retryableCodes;
-    if (newRetryableCodes == null) {
-      newRetryableCodes = this.retryableCodes;
-    }
-
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(extraHeaders, fakeCallContext.extraHeaders);
-
-    ApiCallContextOptions newOptions = options.merge(fakeCallContext.options);
-
-    return new FakeCallContext(
-        newCallCredentials,
-        newChannel,
-        newTimeout,
-        newStreamWaitTimeout,
-        newStreamIdleTimeout,
-        newExtraHeaders,
-        newOptions,
-        newTracer,
-        newRetrySettings,
-        newRetryableCodes);
-  }
-
-  public RetrySettings getRetrySettings() {
-    return retrySettings;
-  }
-
-  public FakeCallContext withRetrySettings(RetrySettings retrySettings) {
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        retrySettings,
-        this.retryableCodes);
-  }
-
-  public Set<StatusCode.Code> getRetryableCodes() {
-    return retryableCodes;
-  }
-
-  public FakeCallContext withRetryableCodes(Set<StatusCode.Code> retryableCodes) {
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        retryableCodes);
-  }
-
-  public Credentials getCredentials() {
-    return credentials;
-  }
-
-  public FakeChannel getChannel() {
-    return channel;
-  }
-
-  @Override
-  public Duration getTimeout() {
-    return timeout;
-  }
-
-  @Nullable
-  @Override
-  public Duration getStreamWaitTimeout() {
-    return streamWaitTimeout;
-  }
-
-  @Nullable
-  @Override
-  public Duration getStreamIdleTimeout() {
-    return streamIdleTimeout;
-  }
-
-  @Override
-  public FakeCallContext withCredentials(Credentials credentials) {
-    return new FakeCallContext(
-        credentials,
-        this.channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public FakeCallContext withTransportChannel(TransportChannel inputChannel) {
-    Preconditions.checkNotNull(inputChannel);
-    if (!(inputChannel instanceof FakeTransportChannel)) {
-      throw new IllegalArgumentException(
-          "Expected FakeTransportChannel, got " + inputChannel.getClass().getName());
-    }
-    FakeTransportChannel transportChannel = (FakeTransportChannel) inputChannel;
-    return withChannel(transportChannel.getChannel());
-  }
-
-  public FakeCallContext withChannel(FakeChannel channel) {
-    return new FakeCallContext(
-        this.credentials,
-        channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public FakeCallContext withTimeout(Duration timeout) {
-    // Default RetrySettings use 0 for RPC timeout. Treat that as disabled timeouts.
-    if (timeout != null && (timeout.isZero() || timeout.isNegative())) {
-      timeout = null;
-    }
-
-    // Prevent expanding timeouts
-    if (timeout != null && this.timeout != null && this.timeout.compareTo(timeout) <= 0) {
-      return this;
-    }
-
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public ApiCallContext withStreamWaitTimeout(@Nullable Duration streamWaitTimeout) {
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        this.timeout,
-        streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public ApiCallContext withStreamIdleTimeout(@Nullable Duration streamIdleTimeout) {
-    Preconditions.checkNotNull(streamIdleTimeout);
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public ApiCallContext withExtraHeaders(Map<String, List<String>> extraHeaders) {
-    Preconditions.checkNotNull(extraHeaders);
-    ImmutableMap<String, List<String>> newExtraHeaders =
-        Headers.mergeHeaders(this.extraHeaders, extraHeaders);
-    return new FakeCallContext(
-        credentials,
-        channel,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        newExtraHeaders,
-        this.options,
-        this.tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  @Override
-  public Map<String, List<String>> getExtraHeaders() {
-    return this.extraHeaders;
-  }
-
-  @Override
-  public <T> ApiCallContext withOption(Key<T> key, T value) {
-    Preconditions.checkNotNull(key);
-    ApiCallContextOptions newOptions = options.withOption(key, value);
-    return new FakeCallContext(
-        credentials,
-        channel,
-        timeout,
-        streamWaitTimeout,
-        streamIdleTimeout,
-        extraHeaders,
-        newOptions,
-        tracer,
-        retrySettings,
-        retryableCodes);
-  }
-
-  @Override
-  public <T> T getOption(Key<T> key) {
-    Preconditions.checkNotNull(key);
-    return options.getOption(key);
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  @Nonnull
-  public ApiTracer getTracer() {
-    if (tracer == null) {
-      return BaseApiTracer.getInstance();
-    }
-    return tracer;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  public ApiCallContext withTracer(@Nonnull ApiTracer tracer) {
-    Preconditions.checkNotNull(tracer);
-
-    return new FakeCallContext(
-        this.credentials,
-        this.channel,
-        this.timeout,
-        this.streamWaitTimeout,
-        this.streamIdleTimeout,
-        this.extraHeaders,
-        this.options,
-        tracer,
-        this.retrySettings,
-        this.retryableCodes);
-  }
-
-  public static FakeCallContext create(ClientContext clientContext) {
-    return FakeCallContext.createDefault()
-        .withTransportChannel(clientContext.getTransportChannel())
-        .withCredentials(clientContext.getCredentials());
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallableFactory.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallableFactory.java
deleted file mode 100644
index 017ffa561..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeCallableFactory.java
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.BatchingCallSettings;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.Callables;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.LongRunningClient;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-
-@InternalApi("for testing")
-public class FakeCallableFactory {
-  private FakeCallableFactory() {}
-
-  private static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBaseUnaryCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        new FakeExceptionCallable<>(innerCallable, callSettings.getRetryableCodes());
-    callable = Callables.retrying(callable, callSettings, clientContext);
-    return callable;
-  }
-
-  /**
-   * Create a callable object with grpc-specific functionality. Designed for use by generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param callSettings {@link UnaryCallSettings} to configure the method-level settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      UnaryCallSettings<RequestT, ResponseT> callSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        createBaseUnaryCallable(innerCallable, callSettings, clientContext);
-    return callable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a callable object that represents a simple call to a paged API method. Designed for use
-   * by generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the method-level settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, ResponseT> createUnpagedCallable(
-          UnaryCallable<RequestT, ResponseT> innerCallable,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        createBaseUnaryCallable(innerCallable, pagedCallSettings, clientContext);
-    return callable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a paged callable object that represents a paged API method. Designed for use by
-   * generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param pagedCallSettings {@link PagedCallSettings} to configure the paged settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT, PagedListResponseT>
-      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
-          UnaryCallable<RequestT, ResponseT> innerCallable,
-          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> pagedCallSettings,
-          ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        createBaseUnaryCallable(innerCallable, pagedCallSettings, clientContext);
-    UnaryCallable<RequestT, PagedListResponseT> pagedCallable =
-        Callables.paged(callable, pagedCallSettings);
-    return pagedCallable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a callable object that represents a batching API method. Designed for use by generated
-   * code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param batchingCallSettings {@link BatchingCallSettings} to configure the batching related
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link UnaryCallable} callable object.
-   */
-  public static <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
-      UnaryCallable<RequestT, ResponseT> innerCallable,
-      BatchingCallSettings<RequestT, ResponseT> batchingCallSettings,
-      ClientContext clientContext) {
-    UnaryCallable<RequestT, ResponseT> callable =
-        createBaseUnaryCallable(innerCallable, batchingCallSettings, clientContext);
-    callable = Callables.batching(callable, batchingCallSettings, clientContext);
-    return callable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Creates a callable object that represents a long-running operation. Designed for use by
-   * generated code.
-   *
-   * @param innerCallable the callable that starts the operation
-   * @param operationCallSettings {@link OperationCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @param longRunningClient {@link LongRunningClient} to use to poll for updates on the Operation.
-   * @return {@link com.google.api.gax.rpc.OperationCallable} callable object.
-   */
-  public static <RequestT, ResponseT, MetadataT>
-      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
-          UnaryCallable<RequestT, OperationSnapshot> innerCallable,
-          OperationCallSettings<RequestT, ResponseT, MetadataT> operationCallSettings,
-          ClientContext clientContext,
-          LongRunningClient longRunningClient) {
-    UnaryCallable<RequestT, OperationSnapshot> initialCallable =
-        createBaseUnaryCallable(
-            innerCallable, operationCallSettings.getInitialCallSettings(), clientContext);
-    OperationCallable<RequestT, ResponseT, MetadataT> operationCallable =
-        Callables.longRunningOperation(
-            initialCallable, operationCallSettings, clientContext, longRunningClient);
-    return operationCallable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a bidirectional streaming callable object with grpc-specific functionality. Designed for
-   * use by generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link BidiStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
-          BidiStreamingCallable<RequestT, ResponseT> innerCallable,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return innerCallable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a server-streaming callable with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link ServerStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
-          ServerStreamingCallable<RequestT, ResponseT> innerCallable,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return innerCallable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-
-  /**
-   * Create a client-streaming callable object with grpc-specific functionality. Designed for use by
-   * generated code.
-   *
-   * @param innerCallable the callable that performs the work
-   * @param streamingCallSettings {@link StreamingCallSettings} to configure the method-level
-   *     settings with.
-   * @param clientContext {@link ClientContext} to use to connect to the service.
-   * @return {@link ClientStreamingCallable} callable object.
-   */
-  public static <RequestT, ResponseT>
-      ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
-          ClientStreamingCallable<RequestT, ResponseT> innerCallable,
-          StreamingCallSettings<RequestT, ResponseT> streamingCallSettings,
-          ClientContext clientContext) {
-    return innerCallable.withDefaultCallContext(FakeCallContext.create(clientContext));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeChannel.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeChannel.java
deleted file mode 100644
index b725da363..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeChannel.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-
-@InternalApi("for testing")
-public class FakeChannel {}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeClientSettings.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeClientSettings.java
deleted file mode 100644
index 7bd913993..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeClientSettings.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.ClientSettings;
-import com.google.api.gax.rpc.StubSettings;
-import java.io.IOException;
-
-@InternalApi("for testing")
-public class FakeClientSettings extends ClientSettings {
-
-  private FakeClientSettings(Builder builder) throws IOException {
-    super(builder);
-  }
-
-  @Override
-  public ClientSettings.Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  public static class Builder extends ClientSettings.Builder {
-
-    public Builder(ClientSettings settings) {
-      super(settings);
-    }
-
-    public Builder(ClientContext clientContext) {
-      super(new FakeStubSettings.Builder(clientContext));
-    }
-
-    public Builder(StubSettings stubSettings) {
-      super(stubSettings.toBuilder());
-    }
-
-    public Builder() {
-      super(new FakeStubSettings.Builder());
-    }
-
-    @Override
-    public FakeClientSettings build() throws IOException {
-      return new FakeClientSettings(this);
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeExceptionCallable.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeExceptionCallable.java
deleted file mode 100644
index 89a8c9128..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeExceptionCallable.java
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutureCallback;
-import com.google.api.core.ApiFutures;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableSet;
-import java.util.Set;
-import java.util.concurrent.CancellationException;
-
-/**
- * Transforms all {@code Throwable}s thrown during a call into an instance of {@link ApiException}.
- *
- * <p>Package-private for internal use.
- */
-class FakeExceptionCallable<RequestT, ResponseT> extends UnaryCallable<RequestT, ResponseT> {
-  private final UnaryCallable<RequestT, ResponseT> callable;
-  private final ImmutableSet<Code> retryableCodes;
-
-  FakeExceptionCallable(UnaryCallable<RequestT, ResponseT> callable, Set<Code> retryableCodes) {
-    this.callable = Preconditions.checkNotNull(callable);
-    this.retryableCodes = ImmutableSet.copyOf(retryableCodes);
-  }
-
-  @Override
-  public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
-    FakeCallContext context = FakeCallContext.createDefault().nullToSelf(inputContext);
-    ApiFuture<ResponseT> innerCallFuture = callable.futureCall(request, context);
-    ExceptionTransformingFuture transformingFuture =
-        new ExceptionTransformingFuture(innerCallFuture);
-    ApiFutures.addCallback(innerCallFuture, transformingFuture, directExecutor());
-    return transformingFuture;
-  }
-
-  private class ExceptionTransformingFuture extends AbstractApiFuture<ResponseT>
-      implements ApiFutureCallback<ResponseT> {
-    private ApiFuture<ResponseT> innerCallFuture;
-    private volatile boolean cancelled = false;
-
-    public ExceptionTransformingFuture(ApiFuture<ResponseT> innerCallFuture) {
-      this.innerCallFuture = innerCallFuture;
-    }
-
-    @Override
-    protected void interruptTask() {
-      cancelled = true;
-      innerCallFuture.cancel(true);
-    }
-
-    @Override
-    public void onSuccess(ResponseT r) {
-      super.set(r);
-    }
-
-    @Override
-    public void onFailure(Throwable throwable) {
-      StatusCode.Code statusCode = StatusCode.Code.UNKNOWN;
-      boolean canRetry = false;
-      boolean rethrow = false;
-      if (throwable instanceof FakeStatusException) {
-        FakeStatusException e = (FakeStatusException) throwable;
-        statusCode = e.getStatusCode().getCode();
-        canRetry = retryableCodes.contains(e.getStatusCode().getCode());
-      } else if (throwable instanceof CancellationException && cancelled) {
-        // this just circled around, so ignore.
-        return;
-      } else if (throwable instanceof ApiException) {
-        rethrow = true;
-      } else {
-        // Do not retry on unknown throwable, even when UNKNOWN is in retryableCodes
-        statusCode = StatusCode.Code.UNKNOWN;
-        canRetry = false;
-      }
-      if (rethrow) {
-        super.setException(throwable);
-      } else {
-        super.setException(
-            ApiExceptionFactory.createException(
-                throwable, FakeStatusCode.of(statusCode), canRetry));
-      }
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeMtlsProvider.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeMtlsProvider.java
deleted file mode 100644
index e5f5c3a91..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeMtlsProvider.java
+++ /dev/null
@@ -1,90 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.client.util.SecurityUtils;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.mtls.MtlsProvider;
-import java.io.IOException;
-import java.io.InputStream;
-import java.security.GeneralSecurityException;
-import java.security.KeyStore;
-
-@InternalApi("for testing")
-public class FakeMtlsProvider extends MtlsProvider {
-  private boolean useClientCertificate;
-  private MtlsEndpointUsagePolicy mtlsEndpointUsagePolicy;
-  private KeyStore keyStore;
-  private boolean throwExceptionForGetKeyStore;
-
-  public FakeMtlsProvider(
-      boolean useClientCertificate,
-      MtlsEndpointUsagePolicy mtlsEndpointUsagePolicy,
-      KeyStore keystore,
-      String keyStorePassword,
-      boolean throwExceptionForGetKeyStore) {
-    super();
-    this.useClientCertificate = useClientCertificate;
-    this.mtlsEndpointUsagePolicy = mtlsEndpointUsagePolicy;
-    this.keyStore = keystore;
-    this.throwExceptionForGetKeyStore = throwExceptionForGetKeyStore;
-  }
-
-  @Override
-  public boolean useMtlsClientCertificate() {
-    return useClientCertificate;
-  }
-
-  @Override
-  public MtlsEndpointUsagePolicy getMtlsEndpointUsagePolicy() {
-    return mtlsEndpointUsagePolicy;
-  }
-
-  @Override
-  public KeyStore getKeyStore() throws IOException {
-    if (throwExceptionForGetKeyStore) {
-      throw new IOException("getKeyStore throws exception");
-    }
-    return keyStore;
-  }
-
-  public static KeyStore createTestMtlsKeyStore() throws IOException {
-    try {
-      InputStream certAndKey =
-          FakeMtlsProvider.class
-              .getClassLoader()
-              .getResourceAsStream("com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem");
-      return SecurityUtils.createMtlsKeyStore(certAndKey);
-    } catch (GeneralSecurityException e) {
-      throw new IOException("Failed to create key store", e);
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationApi.java
deleted file mode 100644
index 7cfb80b12..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationApi.java
+++ /dev/null
@@ -1,147 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.OperationCallable;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.concurrent.ExecutionException;
-
-@InternalApi("for testing")
-public class FakeOperationApi {
-  public static class OperationStashCallable extends OperationCallable<Integer, String, Long> {
-
-    private ApiCallContext context;
-    private Integer request;
-    private Map<String, FakeOperationFuture> operations = new HashMap<>();
-    private ApiCallContext resumeContext;
-    private ApiCallContext cancelContext;
-    private boolean wasCancelCalled = false;
-
-    @Override
-    public OperationFuture<String, Long> futureCall(Integer request, ApiCallContext context) {
-      this.request = request;
-      this.context = context;
-      String opName = "opName-" + request;
-      FakeOperationFuture opFuture = new FakeOperationFuture(request.toString(), opName);
-      operations.put(opName, opFuture);
-      return opFuture;
-    }
-
-    @Override
-    public OperationFuture<String, Long> resumeFutureCall(
-        String operationName, ApiCallContext context) {
-      if (!operations.containsKey(operationName)) {
-        throw new IllegalArgumentException("Operation not found: " + operationName);
-      }
-      resumeContext = context;
-      return operations.get(operationName);
-    }
-
-    @Override
-    public ApiFuture<Void> cancel(String operationName, ApiCallContext context) {
-      wasCancelCalled = true;
-      cancelContext = context;
-      return ApiFutures.immediateFuture(null);
-    }
-
-    public ApiCallContext getContext() {
-      return context;
-    }
-
-    public Integer getRequest() {
-      return request;
-    }
-
-    public ApiCallContext getResumeContext() {
-      return resumeContext;
-    }
-
-    public boolean wasCancelCalled() {
-      return wasCancelCalled;
-    }
-
-    public ApiCallContext getCancelContext() {
-      return cancelContext;
-    }
-  }
-
-  public static class FakeOperationFuture extends AbstractApiFuture<String>
-      implements OperationFuture<String, Long> {
-
-    private final String result;
-    private final String operationName;
-
-    public FakeOperationFuture(String result, String operationName) {
-      this.result = result;
-      this.operationName = operationName;
-    }
-
-    @Override
-    public String get() {
-      return result;
-    }
-
-    @Override
-    public String getName() throws InterruptedException, ExecutionException {
-      return operationName;
-    }
-
-    @Override
-    public ApiFuture<OperationSnapshot> getInitialFuture() {
-      throw new UnsupportedOperationException("getInitialFuture() not implemented");
-    }
-
-    @Override
-    public RetryingFuture<OperationSnapshot> getPollingFuture() {
-      throw new UnsupportedOperationException("getPollingFuture() not implemented");
-    }
-
-    @Override
-    public ApiFuture<Long> peekMetadata() {
-      return null;
-    }
-
-    @Override
-    public ApiFuture<Long> getMetadata() {
-      return null;
-    }
-  }
-
-  public static class FakeOperation {}
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationSnapshot.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationSnapshot.java
deleted file mode 100644
index 59db2a800..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeOperationSnapshot.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.rpc.StatusCode;
-import com.google.auto.value.AutoValue;
-import javax.annotation.Nullable;
-
-@InternalApi("for testing")
-@AutoValue
-public abstract class FakeOperationSnapshot implements OperationSnapshot {
-
-  @Override
-  public abstract String getName();
-
-  @Override
-  @Nullable
-  public abstract Object getMetadata();
-
-  @Override
-  public abstract boolean isDone();
-
-  @Override
-  @Nullable
-  public abstract Object getResponse();
-
-  @Override
-  public abstract StatusCode getErrorCode();
-
-  @Override
-  @Nullable
-  public abstract String getErrorMessage();
-
-  public static Builder newBuilder() {
-    return new AutoValue_FakeOperationSnapshot.Builder();
-  }
-
-  @AutoValue.Builder
-  public abstract static class Builder {
-    public abstract Builder setName(String value);
-
-    public abstract Builder setMetadata(Object value);
-
-    public abstract Builder setDone(boolean value);
-
-    public abstract Builder setResponse(Object value);
-
-    public abstract Builder setErrorCode(StatusCode value);
-
-    public abstract Builder setErrorMessage(String value);
-
-    public abstract FakeOperationSnapshot build();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakePagedApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakePagedApi.java
deleted file mode 100644
index 6d4589d18..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakePagedApi.java
+++ /dev/null
@@ -1,186 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
-
-import com.google.api.core.ApiFunction;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.paging.AbstractFixedSizeCollection;
-import com.google.api.gax.paging.AbstractPage;
-import com.google.api.gax.paging.AbstractPagedListResponse;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.PageContext;
-import com.google.api.gax.rpc.PagedListDescriptor;
-import com.google.api.gax.rpc.PagedListResponseFactory;
-import com.google.api.gax.rpc.UnaryCallable;
-import java.util.List;
-
-@InternalApi("for testing")
-public class FakePagedApi {
-  public static class PagedStashCallable extends UnaryCallable<Integer, List<Integer>> {
-
-    ApiCallContext context;
-    Integer request;
-    List<List<Integer>> results;
-    int currentResultToReturn = 0;
-
-    public PagedStashCallable(List<List<Integer>> results) {
-      this.results = results;
-    }
-
-    @Override
-    public ApiFuture<List<Integer>> futureCall(Integer request, ApiCallContext context) {
-      this.request = request;
-      this.context = context;
-      List<Integer> result = results.get(currentResultToReturn);
-      currentResultToReturn += 1;
-      return ApiFutures.immediateFuture(result);
-    }
-  }
-
-  private static class StashPagedListDescriptor
-      implements PagedListDescriptor<Integer, List<Integer>, Integer> {
-    @Override
-    public String emptyToken() {
-      return "";
-    }
-
-    @Override
-    public Integer injectToken(Integer payload, String token) {
-      return Integer.parseInt(token);
-    }
-
-    @Override
-    public String extractNextToken(List<Integer> payload) {
-      int size = payload.size();
-      return size == 0 ? emptyToken() : payload.get(size - 1).toString();
-    }
-
-    @Override
-    public Iterable<Integer> extractResources(List<Integer> payload) {
-      return payload;
-    }
-
-    @Override
-    public Integer injectPageSize(Integer payload, int pageSize) {
-      return payload;
-    }
-
-    @Override
-    public Integer extractPageSize(Integer payload) {
-      return 3;
-    }
-  }
-
-  public static class ListIntegersPagedResponse
-      extends AbstractPagedListResponse<
-          Integer, List<Integer>, Integer, ListIntegersPage, ListIntegersSizedPage> {
-
-    protected ListIntegersPagedResponse(ListIntegersPage page) {
-      super(page, ListIntegersSizedPage.createEmptyCollection());
-    }
-
-    public static ListIntegersPagedResponse create(
-        PageContext<Integer, List<Integer>, Integer> context, List<Integer> response) {
-      ListIntegersPage page = new ListIntegersPage(context, response);
-      return new ListIntegersPagedResponse(page);
-    }
-
-    public static ApiFuture<ListIntegersPagedResponse> create(
-        PageContext<Integer, List<Integer>, Integer> context,
-        ApiFuture<List<Integer>> futureResponse) {
-      ApiFuture<ListIntegersPage> futurePage =
-          new ListIntegersPage(null, null).createPageAsync(context, futureResponse);
-      return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListIntegersPage, ListIntegersPagedResponse>() {
-            @Override
-            public ListIntegersPagedResponse apply(ListIntegersPage input) {
-              return new ListIntegersPagedResponse(input);
-            }
-          },
-          directExecutor());
-    }
-  }
-
-  private static class ListIntegersPage
-      extends AbstractPage<Integer, List<Integer>, Integer, ListIntegersPage> {
-
-    public ListIntegersPage(
-        PageContext<Integer, List<Integer>, Integer> context, List<Integer> response) {
-      super(context, response);
-    }
-
-    @Override
-    protected ListIntegersPage createPage(
-        PageContext<Integer, List<Integer>, Integer> context, List<Integer> response) {
-      return new ListIntegersPage(context, response);
-    }
-  }
-
-  private static class ListIntegersSizedPage
-      extends AbstractFixedSizeCollection<
-          Integer, List<Integer>, Integer, ListIntegersPage, ListIntegersSizedPage> {
-
-    private ListIntegersSizedPage(List<ListIntegersPage> pages, int collectionSize) {
-      super(pages, collectionSize);
-    }
-
-    private static ListIntegersSizedPage createEmptyCollection() {
-      return new ListIntegersSizedPage(null, 0);
-    }
-
-    @Override
-    protected ListIntegersSizedPage createCollection(
-        List<ListIntegersPage> pages, int collectionSize) {
-      return new ListIntegersSizedPage(pages, collectionSize);
-    }
-  }
-
-  public static class ListIntegersPagedResponseFactory
-      implements PagedListResponseFactory<Integer, List<Integer>, ListIntegersPagedResponse> {
-
-    private final StashPagedListDescriptor streamingDescriptor = new StashPagedListDescriptor();
-
-    @Override
-    public ApiFuture<ListIntegersPagedResponse> getFuturePagedResponse(
-        UnaryCallable<Integer, List<Integer>> callable,
-        Integer request,
-        ApiCallContext context,
-        ApiFuture<List<Integer>> futureResponse) {
-      PageContext<Integer, List<Integer>, Integer> pageContext =
-          PageContext.create(callable, streamingDescriptor, request, context);
-      return ListIntegersPagedResponse.create(pageContext, futureResponse);
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeSimpleApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeSimpleApi.java
deleted file mode 100644
index fce6002b6..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeSimpleApi.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-
-@InternalApi("for testing")
-public class FakeSimpleApi {
-  public static class StashCallable<RequestT, ResponseT>
-      extends UnaryCallable<RequestT, ResponseT> {
-
-    private ApiCallContext context;
-    private RequestT request;
-    private ResponseT result;
-
-    public StashCallable(ResponseT result) {
-      this.result = result;
-    }
-
-    @Override
-    public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext context) {
-      this.request = request;
-      this.context = context;
-      return ApiFutures.immediateFuture(result);
-    }
-
-    public ApiCallContext getContext() {
-      return context;
-    }
-
-    public RequestT getRequest() {
-      return request;
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusCode.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusCode.java
deleted file mode 100644
index 5deb20826..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusCode.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.StatusCode;
-
-@InternalApi("for testing")
-public class FakeStatusCode implements StatusCode {
-  private final Code code;
-
-  public FakeStatusCode(Code code) {
-    this.code = code;
-  }
-
-  @Override
-  public Code getCode() {
-    return code;
-  }
-
-  @Override
-  public Code getTransportCode() {
-    return getCode();
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-
-    FakeStatusCode that = (FakeStatusCode) o;
-
-    return code == that.code;
-  }
-
-  @Override
-  public int hashCode() {
-    return code != null ? code.hashCode() : 0;
-  }
-
-  public static FakeStatusCode of(Code code) {
-    return new FakeStatusCode(code);
-  }
-
-  @Override
-  public String toString() {
-    return code.toString();
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusException.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusException.java
deleted file mode 100644
index 4846b299a..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStatusException.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-
-@InternalApi("for testing")
-public class FakeStatusException extends Exception {
-  private final FakeStatusCode fakeStatusCode;
-
-  public static String formatCode(FakeStatusCode.Code code) {
-    if (code == null) {
-      return "";
-    } else {
-      return code.toString();
-    }
-  }
-
-  public static String formatCodeAsPrefix(FakeStatusCode.Code code) {
-    if (code == null) {
-      return "";
-    } else {
-      return code + ": ";
-    }
-  }
-
-  public FakeStatusException(FakeStatusCode.Code statusCode) {
-    super(formatCode(statusCode));
-    fakeStatusCode = FakeStatusCode.of(statusCode);
-  }
-
-  public FakeStatusException(Throwable cause, FakeStatusCode.Code statusCode) {
-    super(formatCode(statusCode), cause);
-    fakeStatusCode = FakeStatusCode.of(statusCode);
-  }
-
-  public FakeStatusException(String message, Throwable cause, FakeStatusCode.Code statusCode) {
-    super(formatCodeAsPrefix(statusCode) + message, cause);
-    fakeStatusCode = FakeStatusCode.of(statusCode);
-  }
-
-  /**
-   * Returns the status code of the underlying grpc exception. In cases where the underlying
-   * exception is not of type StatusException or StatusRuntimeException, the status code will be
-   * Status.Code.UNKNOWN. For more information about status codes see
-   * https://github.com/grpc/grpc-java/blob/master/api/src/main/java/io/grpc/Status.java
-   */
-  public FakeStatusCode getStatusCode() {
-    return fakeStatusCode;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStreamingApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStreamingApi.java
deleted file mode 100644
index b438c641b..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStreamingApi.java
+++ /dev/null
@@ -1,325 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiExceptionFactory;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamReadyObserver;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.Queues;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.CancellationException;
-
-@InternalApi("for testing")
-public class FakeStreamingApi {
-
-  public static class BidiStreamingStashCallable<RequestT, ResponseT>
-      extends BidiStreamingCallable<RequestT, ResponseT> {
-    private ApiCallContext context;
-    private ResponseObserver<ResponseT> responseObserver;
-    private AccumulatingClientStream<RequestT> clientStream;
-    private List<ResponseT> responseList;
-
-    public BidiStreamingStashCallable() {
-      responseList = new ArrayList<>();
-    }
-
-    public BidiStreamingStashCallable(List<ResponseT> responseList) {
-      this.responseList = responseList;
-    }
-
-    @Override
-    public ClientStream<RequestT> internalCall(
-        ResponseObserver<ResponseT> responseObserver,
-        ClientStreamReadyObserver<RequestT> onReady,
-        ApiCallContext context) {
-      Preconditions.checkNotNull(responseObserver);
-      this.responseObserver = responseObserver;
-      this.context = context;
-      this.clientStream = new AccumulatingClientStream<>();
-
-      StreamControllerStash<ResponseT> controller =
-          new StreamControllerStash<>(responseList, responseObserver);
-      controller.startBidi();
-      onReady.onReady(clientStream);
-
-      return clientStream;
-    }
-
-    public ApiCallContext getContext() {
-      return context;
-    }
-
-    public ResponseObserver<ResponseT> getActualObserver() {
-      return responseObserver;
-    }
-
-    public List<RequestT> getActualRequests() {
-      return clientStream.getValues();
-    }
-
-    private void sendResponses() {
-      for (ResponseT response : responseList) {
-        responseObserver.onResponse(response);
-      }
-      responseObserver.onComplete();
-    }
-
-    private class AccumulatingClientStream<T> implements ClientStream<T> {
-      private List<T> requestList = new ArrayList<>();
-      private Throwable error;
-      private boolean completed = false;
-
-      @Override
-      public void send(T value) {
-        requestList.add(value);
-      }
-
-      @Override
-      public void closeSendWithError(Throwable t) {
-        error = t;
-      }
-
-      @Override
-      public void closeSend() {
-        completed = true;
-      }
-
-      @Override
-      public boolean isSendReady() {
-        return true;
-      }
-
-      public List<T> getValues() {
-        if (!completed) {
-          throw new IllegalStateException("Stream not completed.");
-        }
-        if (error != null) {
-          throw ApiExceptionFactory.createException(error, FakeStatusCode.of(Code.UNKNOWN), false);
-        }
-        return requestList;
-      }
-    }
-  }
-
-  public static class ServerStreamingStashCallable<RequestT, ResponseT>
-      extends ServerStreamingCallable<RequestT, ResponseT> {
-    private ApiCallContext context;
-    private ResponseObserver<ResponseT> actualObserver;
-    private RequestT actualRequest;
-    private List<ResponseT> responseList;
-
-    public ServerStreamingStashCallable() {
-      responseList = new ArrayList<>();
-    }
-
-    public ServerStreamingStashCallable(List<ResponseT> responseList) {
-      this.responseList = responseList;
-    }
-
-    @Override
-    public void call(
-        RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-      Preconditions.checkNotNull(request);
-      Preconditions.checkNotNull(responseObserver);
-      this.actualRequest = request;
-      this.actualObserver = responseObserver;
-      this.context = context;
-
-      StreamControllerStash<ResponseT> controller =
-          new StreamControllerStash<>(responseList, responseObserver);
-      controller.start();
-    }
-
-    public ApiCallContext getContext() {
-      return context;
-    }
-
-    public ResponseObserver<ResponseT> getActualObserver() {
-      return actualObserver;
-    }
-
-    public RequestT getActualRequest() {
-      return actualRequest;
-    }
-  }
-
-  // Minimal implementation of back pressure aware stream controller. Not threadsafe
-  private static class StreamControllerStash<ResponseT> implements StreamController {
-    final ResponseObserver<ResponseT> observer;
-    final Queue<ResponseT> queue;
-    boolean autoFlowControl = true;
-    long numPending;
-    Throwable error;
-    boolean delivering, closed;
-
-    public StreamControllerStash(
-        List<ResponseT> responseList, ResponseObserver<ResponseT> observer) {
-      this.observer = observer;
-      this.queue = Queues.newArrayDeque(responseList);
-    }
-
-    public void start() {
-      observer.onStart(this);
-      if (autoFlowControl) {
-        numPending = Integer.MAX_VALUE;
-      }
-      deliver();
-    }
-
-    public void startBidi() {
-      start();
-    }
-
-    @Override
-    public void disableAutoInboundFlowControl() {
-      autoFlowControl = false;
-    }
-
-    @Override
-    public void request(int count) {
-      numPending += count;
-      deliver();
-    }
-
-    @Override
-    public void cancel() {
-      error = new CancellationException("User cancelled stream");
-      deliver();
-    }
-
-    private void deliver() {
-      if (delivering || closed) return;
-      delivering = true;
-
-      try {
-        while (error == null && numPending > 0 && !queue.isEmpty()) {
-          numPending--;
-          observer.onResponse(queue.poll());
-        }
-
-        if (error != null || queue.isEmpty()) {
-          if (error != null) {
-            observer.onError(error);
-          } else {
-            observer.onComplete();
-          }
-          closed = true;
-        }
-      } finally {
-        delivering = false;
-      }
-    }
-  }
-
-  public static class ClientStreamingStashCallable<RequestT, ResponseT>
-      extends ClientStreamingCallable<RequestT, ResponseT> {
-    private ApiCallContext context;
-    private ApiStreamObserver<ResponseT> responseObserver;
-    private AccumulatingStreamObserver<RequestT> requestObserver;
-    private ResponseT response;
-
-    public ClientStreamingStashCallable() {}
-
-    public ClientStreamingStashCallable(ResponseT response) {
-      this.response = response;
-    }
-
-    @Override
-    public ApiStreamObserver<RequestT> clientStreamingCall(
-        ApiStreamObserver<ResponseT> responseObserver, ApiCallContext context) {
-      Preconditions.checkNotNull(responseObserver);
-      this.responseObserver = responseObserver;
-      this.context = context;
-      this.requestObserver = new AccumulatingStreamObserver<>();
-      return requestObserver;
-    }
-
-    public ApiCallContext getContext() {
-      return context;
-    }
-
-    public ApiStreamObserver<ResponseT> getActualObserver() {
-      return responseObserver;
-    }
-
-    public List<RequestT> getActualRequests() {
-      return requestObserver.getValues();
-    }
-
-    private void sendResponses() {
-      responseObserver.onNext(response);
-      responseObserver.onCompleted();
-    }
-
-    private class AccumulatingStreamObserver<T> implements ApiStreamObserver<T> {
-      private List<T> requestList = new ArrayList<>();
-      private Throwable error;
-      private boolean completed = false;
-
-      @Override
-      public void onNext(T value) {
-        requestList.add(value);
-      }
-
-      @Override
-      public void onError(Throwable t) {
-        error = t;
-      }
-
-      @Override
-      public void onCompleted() {
-        completed = true;
-        ClientStreamingStashCallable.this.sendResponses();
-      }
-
-      public List<T> getValues() {
-        if (!completed) {
-          throw new IllegalStateException("Stream not completed.");
-        }
-        if (error != null) {
-          throw ApiExceptionFactory.createException(error, FakeStatusCode.of(Code.UNKNOWN), false);
-        }
-        return requestList;
-      }
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStubSettings.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStubSettings.java
deleted file mode 100644
index 2c41d75a4..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeStubSettings.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.StubSettings;
-import java.io.IOException;
-
-@InternalApi("for testing")
-public class FakeStubSettings extends StubSettings {
-
-  private FakeStubSettings(Builder builder) throws IOException {
-    super(builder);
-  }
-
-  @Override
-  public StubSettings.Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  public static class Builder extends StubSettings.Builder {
-
-    public Builder(ClientContext clientContext) {
-      super(clientContext);
-    }
-
-    public Builder(StubSettings stubSettings) {
-      super(stubSettings);
-    }
-
-    public Builder() {
-      super((ClientContext) null);
-    }
-
-    @Override
-    public com.google.api.gax.rpc.testing.FakeStubSettings build() throws IOException {
-      return new com.google.api.gax.rpc.testing.FakeStubSettings(this);
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeTransportChannel.java b/gax/src/test/java/com/google/api/gax/rpc/testing/FakeTransportChannel.java
deleted file mode 100644
index 0d4abac8f..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/FakeTransportChannel.java
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.InternalApi;
-import com.google.api.gax.rpc.TransportChannel;
-import java.util.Map;
-import java.util.concurrent.Executor;
-import java.util.concurrent.TimeUnit;
-
-@InternalApi("for testing")
-public class FakeTransportChannel implements TransportChannel {
-  private final FakeChannel channel;
-  private volatile boolean isShutdown = false;
-  private volatile Map<String, String> headers;
-  private volatile Executor executor;
-
-  private FakeTransportChannel(FakeChannel channel) {
-    this.channel = channel;
-  }
-
-  public static FakeTransportChannel create(FakeChannel channel) {
-    return new FakeTransportChannel(channel);
-  }
-
-  /** The name of the Fake transport. */
-  public static String getFakeTransportName() {
-    return "fake";
-  }
-
-  @Override
-  public String getTransportName() {
-    return getFakeTransportName();
-  }
-
-  @Override
-  public FakeCallContext getEmptyCallContext() {
-    return FakeCallContext.createDefault();
-  }
-
-  @Override
-  public void shutdown() {
-    isShutdown = true;
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return isShutdown;
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return isShutdown;
-  }
-
-  @Override
-  public void shutdownNow() {
-    isShutdown = true;
-  }
-
-  @Override
-  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
-    return false;
-  }
-
-  @Override
-  public void close() {}
-
-  public FakeChannel getChannel() {
-    return channel;
-  }
-
-  public void setHeaders(Map<String, String> headers) {
-    this.headers = headers;
-  }
-
-  public Map<String, String> getHeaders() {
-    return this.headers;
-  }
-
-  public void setExecutor(Executor executor) {
-    this.executor = executor;
-  }
-
-  public Executor getExecutor() {
-    return executor;
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/rpc/testing/MockStreamingApi.java b/gax/src/test/java/com/google/api/gax/rpc/testing/MockStreamingApi.java
deleted file mode 100644
index 4daab63e9..000000000
--- a/gax/src/test/java/com/google/api/gax/rpc/testing/MockStreamingApi.java
+++ /dev/null
@@ -1,208 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.rpc.testing;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StateCheckingResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import com.google.common.collect.Queues;
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-
-public class MockStreamingApi {
-  public static class MockServerStreamingCallable<RequestT, ResponseT>
-      extends ServerStreamingCallable<RequestT, ResponseT> {
-    private final BlockingQueue<MockServerStreamingCall<RequestT, ResponseT>> calls =
-        Queues.newLinkedBlockingDeque();
-
-    @Override
-    public void call(
-        RequestT request, ResponseObserver<ResponseT> responseObserver, ApiCallContext context) {
-      MockStreamController<ResponseT> controller = new MockStreamController<>(responseObserver);
-      calls.add(new MockServerStreamingCall<>(request, controller));
-      responseObserver.onStart(controller);
-    }
-
-    public MockServerStreamingCall<RequestT, ResponseT> popLastCall() {
-      try {
-        return calls.poll(1, TimeUnit.SECONDS);
-      } catch (Throwable e) {
-        return null;
-      }
-    }
-  }
-
-  public static class MockServerStreamingCall<RequestT, ResponseT> {
-    private final RequestT request;
-    private final MockStreamController<ResponseT> controller;
-
-    public MockServerStreamingCall(RequestT request, MockStreamController<ResponseT> controller) {
-      this.request = request;
-      this.controller = controller;
-    }
-
-    public RequestT getRequest() {
-      return request;
-    }
-
-    public MockStreamController<ResponseT> getController() {
-      return controller;
-    }
-  }
-
-  public static class MockStreamController<ResponseT> implements StreamController {
-    private final ResponseObserver<ResponseT> downstreamObserver;
-    private final BlockingQueue<Integer> pulls = Queues.newLinkedBlockingQueue();
-    private SettableApiFuture<Boolean> cancelFuture = SettableApiFuture.create();
-    private boolean autoFlowControl = true;
-
-    public MockStreamController(ResponseObserver<ResponseT> downstreamObserver) {
-      this.downstreamObserver = downstreamObserver;
-    }
-
-    @Override
-    public void disableAutoInboundFlowControl() {
-      autoFlowControl = false;
-    }
-
-    @Override
-    public void request(int count) {
-      pulls.add(count);
-    }
-
-    @Override
-    public void cancel() {
-      cancelFuture.set(true);
-    }
-
-    public ResponseObserver<ResponseT> getObserver() {
-      return downstreamObserver;
-    }
-
-    public boolean isAutoFlowControlEnabled() {
-      return autoFlowControl;
-    }
-
-    public boolean isCancelled() {
-      return cancelFuture.isDone();
-    }
-
-    public void waitForCancel() {
-      try {
-        cancelFuture.get(1, TimeUnit.SECONDS);
-      } catch (Exception e) {
-        throw new RuntimeException(e);
-      }
-    }
-
-    public int popLastPull() {
-      Integer results;
-
-      try {
-        results = pulls.poll(1, TimeUnit.SECONDS);
-      } catch (InterruptedException e) {
-        Thread.currentThread().interrupt();
-        throw new RuntimeException(e);
-      }
-
-      if (results == null) {
-        return 0;
-      } else {
-        return results;
-      }
-    }
-  }
-
-  public static class MockResponseObserver<T> extends StateCheckingResponseObserver<T> {
-    private final boolean autoFlowControl;
-    private StreamController controller;
-    private final BlockingQueue<T> responses = Queues.newLinkedBlockingDeque();
-    private final SettableApiFuture<Void> done = SettableApiFuture.create();
-
-    public MockResponseObserver(boolean autoFlowControl) {
-      this.autoFlowControl = autoFlowControl;
-    }
-
-    @Override
-    protected void onStartImpl(StreamController controller) {
-      this.controller = controller;
-      if (!autoFlowControl) {
-        controller.disableAutoInboundFlowControl();
-      }
-    }
-
-    @Override
-    protected void onResponseImpl(T response) {
-      responses.add(response);
-    }
-
-    @Override
-    protected void onErrorImpl(Throwable t) {
-      done.setException(t);
-    }
-
-    @Override
-    protected void onCompleteImpl() {
-      done.set(null);
-    }
-
-    public StreamController getController() {
-      return controller;
-    }
-
-    public T popNextResponse() {
-      try {
-        return responses.poll(1, TimeUnit.SECONDS);
-      } catch (InterruptedException e) {
-        Thread.currentThread().interrupt();
-        throw new RuntimeException(e);
-      }
-    }
-
-    public Throwable getFinalError() {
-      try {
-        done.get(1, TimeUnit.SECONDS);
-        return null;
-      } catch (ExecutionException e) {
-        return e.getCause();
-      } catch (Throwable t) {
-        return t;
-      }
-    }
-
-    public boolean isDone() {
-      return done.isDone();
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerFactoryTest.java b/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerFactoryTest.java
deleted file mode 100644
index 457492acf..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerFactoryTest.java
+++ /dev/null
@@ -1,155 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.ArgumentMatchers.nullable;
-import static org.mockito.ArgumentMatchers.same;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.collect.ImmutableMap;
-import io.grpc.Context;
-import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.SpanBuilder;
-import io.opencensus.trace.Tracer;
-import io.opencensus.trace.unsafe.ContextUtils;
-import java.util.Map;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-
-@RunWith(JUnit4.class)
-public class OpencensusTracerFactoryTest {
-  @Rule public final MockitoRule mockitoRule = MockitoJUnit.rule();
-  @Mock private Tracer internalTracer;
-  @Mock private SpanBuilder spanBuilder;
-  @Mock private Span span;
-  private final Map<String, String> defaultSpanAttributes = ImmutableMap.of();
-
-  @Before
-  public void setUp() {
-    when(internalTracer.spanBuilderWithExplicitParent(anyString(), nullable(Span.class)))
-        .thenReturn(spanBuilder);
-
-    when(spanBuilder.setRecordEvents(true)).thenReturn(spanBuilder);
-
-    when(spanBuilder.startSpan()).thenReturn(span);
-  }
-
-  @Test
-  public void testSpanNamePassthrough() {
-    OpencensusTracerFactory factory =
-        new OpencensusTracerFactory(internalTracer, ImmutableMap.<String, String>of());
-
-    factory.newTracer(
-        BaseApiTracer.getInstance(), SpanName.of("FakeClient", "FakeMethod"), OperationType.Unary);
-
-    verify(internalTracer)
-        .spanBuilderWithExplicitParent(eq("FakeClient.FakeMethod"), nullable(Span.class));
-  }
-
-  @Test
-  public void testImplicitParentSpan() {
-    OpencensusTracerFactory factory =
-        new OpencensusTracerFactory(internalTracer, defaultSpanAttributes);
-
-    Span parentSpan = mock(Span.class);
-    Context origContext = ContextUtils.withValue(Context.current(), parentSpan).attach();
-
-    try {
-      factory.newTracer(
-          BaseApiTracer.getInstance(),
-          SpanName.of("FakeClient", "FakeMethod"),
-          OperationType.Unary);
-    } finally {
-      Context.current().detach(origContext);
-    }
-
-    verify(internalTracer).spanBuilderWithExplicitParent(anyString(), same(parentSpan));
-  }
-
-  @Test
-  public void testExplicitParent() {
-    OpencensusTracerFactory factory =
-        new OpencensusTracerFactory(internalTracer, defaultSpanAttributes);
-
-    Span parentSpan = mock(Span.class);
-    OpencensusTracer parentTracer =
-        new OpencensusTracer(internalTracer, parentSpan, OperationType.Unary);
-
-    factory.newTracer(parentTracer, SpanName.of("FakeClient", "FakeMethod"), OperationType.Unary);
-
-    verify(internalTracer).spanBuilderWithExplicitParent(anyString(), same(parentSpan));
-  }
-
-  @Test
-  public void testExplicitParentOverridesImplicit() {
-    OpencensusTracerFactory factory =
-        new OpencensusTracerFactory(internalTracer, defaultSpanAttributes);
-
-    Span parentSpan = mock(Span.class);
-    OpencensusTracer parentTracer =
-        new OpencensusTracer(internalTracer, parentSpan, OperationType.Unary);
-
-    Context origContext = ContextUtils.withValue(Context.current(), parentSpan).attach();
-
-    try {
-      factory.newTracer(parentTracer, SpanName.of("FakeClient", "FakeMethod"), OperationType.Unary);
-    } finally {
-      Context.current().detach(origContext);
-    }
-
-    verify(internalTracer).spanBuilderWithExplicitParent(anyString(), same(parentSpan));
-  }
-
-  @Test
-  public void testSpanAttributes() {
-    OpencensusTracerFactory factory =
-        new OpencensusTracerFactory(internalTracer, ImmutableMap.of("gax.version", "1.2.3"));
-
-    factory.newTracer(
-        BaseApiTracer.getInstance(), SpanName.of("FakeClient", "FakeMethod"), OperationType.Unary);
-
-    verify(span, times(1))
-        .putAttributes(
-            ImmutableMap.of("gax.version", AttributeValue.stringAttributeValue("1.2.3")));
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerTest.java b/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerTest.java
deleted file mode 100644
index 8cf6f82fa..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/OpencensusTracerTest.java
+++ /dev/null
@@ -1,383 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.eq;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-
-import com.google.api.gax.retrying.ServerStreamingAttemptException;
-import com.google.api.gax.rpc.ApiException;
-import com.google.api.gax.rpc.DeadlineExceededException;
-import com.google.api.gax.rpc.NotFoundException;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.collect.ImmutableMap;
-import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.EndSpanOptions;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Status;
-import io.opencensus.trace.Status.CanonicalCode;
-import io.opencensus.trace.Tracer;
-import java.util.Map;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Captor;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class OpencensusTracerTest {
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private Tracer internalTracer;
-  @Mock private Span span;
-  @Captor private ArgumentCaptor<Map<String, AttributeValue>> attributeCaptor;
-
-  private OpencensusTracer tracer;
-
-  @Before
-  public void setUp() {
-    tracer = new OpencensusTracer(internalTracer, span, OperationType.Unary);
-  }
-
-  @Test
-  public void testUnarySuccessExample() {
-    tracer.attemptStarted(0);
-    tracer.connectionSelected("1");
-    ApiException error0 =
-        new DeadlineExceededException(
-            "deadline exceeded", null, new FakeStatusCode(Code.DEADLINE_EXCEEDED), true);
-    tracer.attemptFailed(error0, Duration.ofMillis(5));
-
-    tracer.attemptStarted(1);
-    tracer.connectionSelected("2");
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    // Attempt 0
-    verify(span)
-        .addAnnotation(
-            "Attempt failed, scheduling next attempt",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(0),
-                "delay ms", AttributeValue.longAttributeValue(5),
-                "status", AttributeValue.stringAttributeValue("DEADLINE_EXCEEDED"),
-                "status message", AttributeValue.stringAttributeValue("deadline exceeded"),
-                "connection", AttributeValue.stringAttributeValue("1")));
-
-    // Attempt 1
-    verify(span)
-        .addAnnotation(
-            "Attempt succeeded",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(1),
-                "connection", AttributeValue.stringAttributeValue("2")));
-
-    verify(span)
-        .putAttributes(ImmutableMap.of("attempt count", AttributeValue.longAttributeValue(2)));
-    verify(span).end();
-
-    verifyNoMoreInteractions(span);
-  }
-
-  @Test
-  public void testBatchExample() {
-    tracer.batchRequestSent(100, 1000);
-    tracer.attemptStarted(0);
-    tracer.connectionSelected("1");
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    verify(span).putAttribute("batch count", AttributeValue.longAttributeValue(100));
-    verify(span).putAttribute("batch size", AttributeValue.longAttributeValue(1000));
-  }
-
-  @Test
-  public void testLongRunningExample() {
-    tracer = new OpencensusTracer(internalTracer, span, OperationType.LongRunning);
-
-    // Initial poll of the initial rpc
-    tracer.attemptStarted(0);
-    tracer.attemptFailed(null, Duration.ofMillis(5));
-
-    // Initial rpc finished
-    tracer.lroStartSucceeded();
-
-    // First real poll
-    tracer.attemptStarted(1);
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    // Attempt 0 - initial poll of the initial rpc
-    verify(span)
-        .addAnnotation(
-            "Scheduling next poll",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(0),
-                "delay ms", AttributeValue.longAttributeValue(5),
-                "status", AttributeValue.stringAttributeValue("OK")));
-
-    verify(span).addAnnotation("Operation started", ImmutableMap.<String, AttributeValue>of());
-
-    // Attempt 1 - first real poll
-    verify(span)
-        .addAnnotation(
-            "Polling completed", ImmutableMap.of("attempt", AttributeValue.longAttributeValue(1)));
-
-    verify(span)
-        .putAttributes(ImmutableMap.of("attempt count", AttributeValue.longAttributeValue(2)));
-    verify(span).end();
-
-    verifyNoMoreInteractions(span);
-  }
-
-  @Test
-  public void testRetriesExhaustedExample() {
-    tracer.attemptStarted(0);
-    tracer.connectionSelected("1");
-    ApiException error0 =
-        new DeadlineExceededException(
-            "deadline exceeded", null, new FakeStatusCode(Code.DEADLINE_EXCEEDED), false);
-    tracer.attemptFailedRetriesExhausted(error0);
-    tracer.operationFailed(error0);
-
-    verify(span)
-        .addAnnotation(
-            "Attempts exhausted",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(0),
-                "status", AttributeValue.stringAttributeValue("DEADLINE_EXCEEDED"),
-                "status message", AttributeValue.stringAttributeValue("deadline exceeded"),
-                "connection", AttributeValue.stringAttributeValue("1")));
-
-    verify(span)
-        .putAttributes(ImmutableMap.of("attempt count", AttributeValue.longAttributeValue(1)));
-
-    verify(span)
-        .end(
-            EndSpanOptions.builder()
-                .setStatus(Status.DEADLINE_EXCEEDED.withDescription("deadline exceeded"))
-                .build());
-
-    verifyNoMoreInteractions(span);
-  }
-
-  @Test
-  public void testCancellationExample() {
-    tracer.attemptStarted(0);
-    tracer.connectionSelected("1");
-    tracer.attemptCancelled();
-    tracer.operationCancelled();
-
-    verify(span)
-        .addAnnotation(
-            "Attempt cancelled",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(0),
-                "connection", AttributeValue.stringAttributeValue("1")));
-
-    verify(span)
-        .putAttributes(ImmutableMap.of("attempt count", AttributeValue.longAttributeValue(1)));
-
-    verify(span)
-        .end(
-            EndSpanOptions.builder()
-                .setStatus(Status.CANCELLED.withDescription("Cancelled by caller"))
-                .build());
-    verifyNoMoreInteractions(span);
-  }
-
-  @Test
-  public void testFailureExample() {
-    tracer.attemptStarted(0);
-    tracer.connectionSelected("1");
-    ApiException error0 =
-        new NotFoundException("not found", null, new FakeStatusCode(Code.NOT_FOUND), false);
-    tracer.attemptPermanentFailure(error0);
-    tracer.operationFailed(error0);
-
-    verify(span)
-        .addAnnotation(
-            "Attempt failed, error not retryable",
-            ImmutableMap.of(
-                "attempt", AttributeValue.longAttributeValue(0),
-                "status", AttributeValue.stringAttributeValue("NOT_FOUND"),
-                "status message", AttributeValue.stringAttributeValue("not found"),
-                "connection", AttributeValue.stringAttributeValue("1")));
-
-    verify(span)
-        .putAttributes(ImmutableMap.of("attempt count", AttributeValue.longAttributeValue(1)));
-
-    verify(span)
-        .end(
-            EndSpanOptions.builder()
-                .setStatus(Status.NOT_FOUND.withDescription("not found"))
-                .build());
-    verifyNoMoreInteractions(span);
-  }
-
-  @Test
-  public void testResponseCount() {
-    // Initial attempt got 2 messages, then failed
-    tracer.attemptStarted(0);
-    tracer.responseReceived();
-    tracer.responseReceived();
-    tracer.attemptFailed(new RuntimeException(), Duration.ofMillis(1));
-
-    // Next attempt got 1 message, then successfully finished the attempt and the logical operation.
-    tracer.attemptStarted(1);
-    tracer.responseReceived();
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    verify(span)
-        .addAnnotation(eq("Attempt failed, scheduling next attempt"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt response count", AttributeValue.longAttributeValue(2));
-
-    verify(span).addAnnotation(eq("Attempt succeeded"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt response count", AttributeValue.longAttributeValue(1));
-
-    verify(span).putAttributes(attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("total response count", AttributeValue.longAttributeValue(3));
-  }
-
-  @Test
-  public void testRequestCount() {
-    // Initial attempt sent 2 messages, then failed
-    tracer.attemptStarted(0);
-    tracer.requestSent();
-    tracer.requestSent();
-    tracer.attemptFailed(new RuntimeException(), Duration.ofMillis(1));
-
-    // Next attempt sent 1 message, then successfully finished the attempt and the logical
-    // operation.
-    tracer.attemptStarted(1);
-    tracer.requestSent();
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    verify(span)
-        .addAnnotation(eq("Attempt failed, scheduling next attempt"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt request count", AttributeValue.longAttributeValue(2));
-
-    verify(span).addAnnotation(eq("Attempt succeeded"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt request count", AttributeValue.longAttributeValue(1));
-
-    verify(span).putAttributes(attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("total request count", AttributeValue.longAttributeValue(3));
-  }
-
-  @Test
-  public void testAttemptNumber() {
-    tracer.attemptStarted(0);
-    tracer.attemptFailed(new RuntimeException(), Duration.ofMillis(1));
-    tracer.attemptStarted(1);
-    tracer.attemptSucceeded();
-    tracer.operationSucceeded();
-
-    verify(span)
-        .addAnnotation(eq("Attempt failed, scheduling next attempt"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt", AttributeValue.longAttributeValue(0));
-
-    verify(span).addAnnotation(eq("Attempt succeeded"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt", AttributeValue.longAttributeValue(1));
-
-    verify(span).putAttributes(attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("attempt count", AttributeValue.longAttributeValue(2));
-  }
-
-  @Test
-  public void testStatusCode() {
-    tracer.attemptStarted(0);
-    tracer.attemptFailed(
-        new DeadlineExceededException(
-            "deadline exceeded", null, new FakeStatusCode(Code.DEADLINE_EXCEEDED), true),
-        Duration.ofMillis(1));
-
-    tracer.attemptStarted(1);
-    ApiException permanentError =
-        new NotFoundException("not found", null, new FakeStatusCode(Code.NOT_FOUND), false);
-    tracer.attemptPermanentFailure(permanentError);
-    tracer.operationFailed(permanentError);
-
-    verify(span)
-        .addAnnotation(eq("Attempt failed, scheduling next attempt"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("status", AttributeValue.stringAttributeValue("DEADLINE_EXCEEDED"));
-
-    verify(span)
-        .addAnnotation(eq("Attempt failed, error not retryable"), attributeCaptor.capture());
-    assertThat(attributeCaptor.getValue())
-        .containsEntry("status", AttributeValue.stringAttributeValue("NOT_FOUND"));
-  }
-
-  @Test
-  public void testErrorConversion() {
-    for (Code code : Code.values()) {
-      ApiException error = new ApiException("fake message", null, new FakeStatusCode(code), false);
-      Status opencensusStatus = OpencensusTracer.convertErrorToStatus(error);
-      assertThat(opencensusStatus.getDescription()).isEqualTo("fake message");
-      assertThat(opencensusStatus.getCanonicalCode().toString()).isEqualTo(code.toString());
-    }
-  }
-
-  @Test
-  public void testStreamingErrorConversion() {
-    ServerStreamingAttemptException error =
-        new ServerStreamingAttemptException(
-            new DeadlineExceededException(
-                "timeout", null, new FakeStatusCode(Code.DEADLINE_EXCEEDED), true),
-            true,
-            true);
-    Status opencensusStatus = OpencensusTracer.convertErrorToStatus(error);
-    assertThat(opencensusStatus.getDescription()).isEqualTo("timeout");
-    assertThat(opencensusStatus.getCanonicalCode()).isEqualTo(CanonicalCode.DEADLINE_EXCEEDED);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TraceFinisherTest.java b/gax/src/test/java/com/google/api/gax/tracing/TraceFinisherTest.java
deleted file mode 100644
index 5aa94f651..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TraceFinisherTest.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.ApiFutures;
-import com.google.common.util.concurrent.MoreExecutors;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-@RunWith(JUnit4.class)
-public class TraceFinisherTest {
-  @Rule public MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-  @Mock private ApiTracer mockTracer;
-
-  @Test
-  public void testSuccess() {
-    ApiFuture<String> future = ApiFutures.immediateFuture("result");
-    ApiFutures.addCallback(
-        future, new TraceFinisher<String>(mockTracer), MoreExecutors.directExecutor());
-
-    verify(mockTracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testCancellation() {
-    ApiFuture<String> future = ApiFutures.immediateCancelledFuture();
-    ApiFutures.addCallback(
-        future, new TraceFinisher<String>(mockTracer), MoreExecutors.directExecutor());
-
-    verify(mockTracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testFailure() {
-    RuntimeException expectedError = new RuntimeException("fake");
-    ApiFuture<String> future = ApiFutures.immediateFailedFuture(expectedError);
-    ApiFutures.addCallback(
-        future, new TraceFinisher<String>(mockTracer), MoreExecutors.directExecutor());
-
-    verify(mockTracer, times(1)).operationFailed(expectedError);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedBatchingCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedBatchingCallableTest.java
deleted file mode 100644
index 6488dde28..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedBatchingCallableTest.java
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package com.google.api.gax.tracing;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.Mockito.reset;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BatchingDescriptor;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-public class TracedBatchingCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("FakeClient", "FakeRpc");
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  @Mock private ApiTracer tracer;
-  @Mock private BatchingDescriptor<String, String> batchingDescriptor;
-  @Mock private UnaryCallable<String, String> innerCallable;
-  private SettableApiFuture<String> innerResult;
-
-  private TracedBatchingCallable<String, String> tracedBatchingCallable;
-  private FakeCallContext callContext;
-
-  @Before
-  public void setUp() {
-    // Wire the mock tracer factory
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.Batching)))
-        .thenReturn(tracer);
-
-    // Wire the mock inner callable
-    // This is a very hacky mock, the actual batching infrastructure is completely omitted here.
-    innerResult = SettableApiFuture.create();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-
-    // Build the system under test
-    tracedBatchingCallable =
-        new TracedBatchingCallable<>(innerCallable, tracerFactory, SPAN_NAME, batchingDescriptor);
-    callContext = FakeCallContext.createDefault();
-  }
-
-  @Test
-  public void testRootTracerCreated() {
-    tracedBatchingCallable.futureCall("test", callContext);
-    verify(tracerFactory, times(1))
-        .newTracer(callContext.getTracer(), SPAN_NAME, OperationType.Batching);
-  }
-
-  @Test
-  public void testBatchAttributesStamped() {
-    when(batchingDescriptor.countElements(anyString())).thenReturn(10L);
-    when(batchingDescriptor.countBytes(anyString())).thenReturn(20L);
-
-    tracedBatchingCallable.futureCall("test", callContext);
-    verify(tracer).batchRequestSent(10, 20);
-  }
-
-  @Test
-  public void testOperationFinish() {
-    innerResult.set("successful result");
-    tracedBatchingCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testOperationFailed() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-    innerResult.setException(fakeError);
-    tracedBatchingCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-
-  @Test
-  public void testSyncError() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-
-    // Reset the irrelevant expectations from setup. (only needed to silence the warnings).
-    @SuppressWarnings("unchecked")
-    UnaryCallable<String, String>[] innerCallableWrapper = new UnaryCallable[] {innerCallable};
-    reset(innerCallableWrapper);
-
-    when(innerCallable.futureCall(eq("failing test"), any(ApiCallContext.class)))
-        .thenThrow(fakeError);
-
-    try {
-      tracedBatchingCallable.futureCall("failing test", callContext);
-    } catch (RuntimeException e) {
-      // ignored
-    }
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedBidiCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedBidiCallableTest.java
deleted file mode 100644
index 93a007f73..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedBidiCallableTest.java
+++ /dev/null
@@ -1,292 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.BidiStream;
-import com.google.api.gax.rpc.BidiStreamObserver;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStream;
-import com.google.api.gax.rpc.ClientStreamReadyObserver;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.StreamController;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-
-@RunWith(JUnit4.class)
-public class TracedBidiCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("fake-client", "fake-method");
-  public @Rule MockitoRule mockitoRule = MockitoJUnit.rule();
-
-  private FakeBidiObserver outerObserver;
-  private FakeCallContext outerCallContext;
-
-  @Mock private ApiTracerFactory tracerFactory;
-  private ApiTracer parentTracer = BaseApiTracer.getInstance();
-  @Mock private ApiTracer tracer;
-
-  private TracedBidiCallable<String, String> tracedCallable;
-
-  private FakeBidiCallable innerCallable;
-  private FakeStreamController innerController;
-
-  @Before
-  public void setUp() {
-    outerObserver = new FakeBidiObserver();
-    outerCallContext = FakeCallContext.createDefault();
-
-    when(tracerFactory.newTracer(parentTracer, SPAN_NAME, OperationType.BidiStreaming))
-        .thenReturn(tracer);
-
-    innerCallable = new FakeBidiCallable();
-    innerController = new FakeStreamController();
-    tracedCallable = new TracedBidiCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-  }
-
-  @Test
-  public void testTracerCreated() {
-    tracedCallable.call(outerObserver, outerCallContext);
-
-    verify(tracerFactory, times(1)).newTracer(parentTracer, SPAN_NAME, OperationType.BidiStreaming);
-  }
-
-  @Test
-  public void testOperationCancelled() {
-    tracedCallable.call(outerObserver, outerCallContext);
-    outerObserver.clientStream.closeSendWithError(new CancellationException());
-    innerCallable.responseObserver.onError(
-        new RuntimeException("server generated result from cancelling"));
-
-    verify(tracer, times(1)).operationCancelled();
-    assertThat(outerObserver.complete).isTrue();
-  }
-
-  @Test
-  public void testOperationCancelled2() {
-    BidiStream<String, String> stream = tracedCallable.call(outerCallContext);
-
-    stream.cancel();
-    innerCallable.responseObserver.onError(
-        new RuntimeException("server generated result from cancelling"));
-
-    verify(tracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testOperationFinished() {
-    tracedCallable.call(outerObserver, outerCallContext);
-    innerCallable.responseObserver.onComplete();
-
-    verify(tracer, times(1)).operationSucceeded();
-    assertThat(outerObserver.complete).isTrue();
-  }
-
-  @Test
-  public void testOperationFailed() {
-    RuntimeException expectedException = new RuntimeException("fake");
-
-    tracedCallable.call(outerObserver, outerCallContext);
-    innerCallable.responseObserver.onError(expectedException);
-
-    verify(tracer, times(1)).operationFailed(expectedException);
-    assertThat(outerObserver.complete).isTrue();
-    assertThat(outerObserver.error).isEqualTo(expectedException);
-  }
-
-  @Test
-  public void testSyncError() {
-    RuntimeException expectedException = new RuntimeException("fake");
-    innerCallable.syncError = expectedException;
-
-    try {
-      tracedCallable.call(outerObserver, outerCallContext);
-    } catch (RuntimeException e) {
-      // noop
-    }
-
-    verify(tracer, times(1)).operationFailed(expectedException);
-  }
-
-  @Test
-  public void testRequestNotify() {
-    tracedCallable.call(outerObserver, outerCallContext);
-    outerObserver.clientStream.send("request1");
-    outerObserver.clientStream.send("request2");
-
-    verify(tracer, times(2)).requestSent();
-    assertThat(innerCallable.clientStream.sent).containsExactly("request1", "request2");
-  }
-
-  @Test
-  public void testRequestNotify2() {
-    BidiStream<String, String> stream = tracedCallable.call(outerCallContext);
-    stream.send("request1");
-    stream.send("request2");
-
-    verify(tracer, times(2)).requestSent();
-    assertThat(innerCallable.clientStream.sent).containsExactly("request1", "request2");
-  }
-
-  @Test
-  public void testResponseNotify() {
-    tracedCallable.call(outerObserver, outerCallContext);
-
-    innerCallable.responseObserver.onResponse("response1");
-    innerCallable.responseObserver.onResponse("response2");
-
-    verify(tracer, times(2)).responseReceived();
-    assertThat(outerObserver.responses).containsExactly("response1", "response2");
-  }
-
-  private static class FakeBidiCallable extends BidiStreamingCallable<String, String> {
-    RuntimeException syncError;
-
-    FakeStreamController responseController;
-    ResponseObserver<String> responseObserver;
-    ClientStreamReadyObserver<String> onReady;
-    ApiCallContext callContext;
-    FakeClientStream clientStream;
-
-    @Override
-    public ClientStream<String> internalCall(
-        ResponseObserver<String> responseObserver,
-        ClientStreamReadyObserver<String> onReady,
-        ApiCallContext context) {
-
-      if (syncError != null) {
-        throw syncError;
-      }
-
-      this.responseController = new FakeStreamController();
-
-      this.responseObserver = responseObserver;
-      this.onReady = onReady;
-      this.callContext = context;
-      this.clientStream = new FakeClientStream();
-
-      onReady.onReady(clientStream);
-      responseObserver.onStart(responseController);
-
-      return clientStream;
-    }
-  }
-
-  private static class FakeClientStream implements ClientStream<String> {
-    private List<String> sent = new ArrayList<>();
-    private Throwable closeError;
-    private boolean closed;
-
-    @Override
-    public void send(String request) {
-      sent.add(request);
-    }
-
-    @Override
-    public void closeSendWithError(Throwable t) {
-      closed = true;
-      closeError = t;
-    }
-
-    @Override
-    public void closeSend() {
-      closed = true;
-    }
-
-    @Override
-    public boolean isSendReady() {
-      return true;
-    }
-  }
-
-  private static class FakeBidiObserver implements BidiStreamObserver<String, String> {
-    private ClientStream<String> clientStream;
-    private StreamController streamController;
-    private List<String> responses = new ArrayList<>();
-    private Throwable error;
-    private boolean complete;
-
-    @Override
-    public void onReady(ClientStream<String> stream) {
-      this.clientStream = stream;
-    }
-
-    @Override
-    public void onStart(StreamController controller) {
-      this.streamController = controller;
-    }
-
-    @Override
-    public void onResponse(String response) {
-      responses.add(response);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      this.error = t;
-      this.complete = true;
-    }
-
-    @Override
-    public void onComplete() {
-      this.complete = true;
-    }
-  }
-
-  private static class FakeStreamController implements StreamController {
-    private boolean wasCancelled;
-
-    @Override
-    public void cancel() {
-      this.wasCancelled = true;
-    }
-
-    @Override
-    public void disableAutoInboundFlowControl() {}
-
-    @Override
-    public void request(int count) {}
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedCallableTest.java
deleted file mode 100644
index 834b357e4..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedCallableTest.java
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.anyString;
-import static org.mockito.Mockito.eq;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.ApiFuture;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.Callables;
-import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.UnaryCallSettings;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-import org.threeten.bp.Duration;
-
-@RunWith(JUnit4.class)
-public class TracedCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("FakeClient", "FakeRpc");
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  private ApiTracer parentTracer;
-  @Mock private ApiTracer tracer;
-  @Mock private UnaryCallable<String, String> innerCallable;
-  private SettableApiFuture<String> innerResult;
-
-  private ApiCallContext callContext;
-  private ClientContext clientContext;
-
-  @Before
-  public void setUp() {
-    parentTracer = BaseApiTracer.getInstance();
-
-    // Wire the mock tracer factory
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.Unary)))
-        .thenReturn(tracer);
-
-    // Wire the mock inner callable
-    innerResult = SettableApiFuture.create();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-
-    callContext = FakeCallContext.createDefault();
-    clientContext = ClientContext.newBuilder().setDefaultCallContext(callContext).build();
-  }
-
-  public UnaryCallable<String, String> setupTracedUnaryCallable(
-      UnaryCallSettings<Object, Object> callSettings) {
-    UnaryCallable<String, String> callable =
-        Callables.retrying(innerCallable, callSettings, clientContext);
-    return new TracedUnaryCallable<>(callable, tracerFactory, SPAN_NAME);
-  }
-
-  @Test
-  public void testNonRetriedCallable() throws Exception {
-    // Verify that callables configured to not retry have the appropriate tracer interactions.
-    UnaryCallSettings<Object, Object> callSettings =
-        UnaryCallSettings.newUnaryCallSettingsBuilder()
-            .setSimpleTimeoutNoRetries(Duration.ofMillis(5L))
-            .build();
-    UnaryCallable<String, String> callable = setupTracedUnaryCallable(callSettings);
-    innerResult.set("No, my refrigerator is not running!");
-
-    ApiFuture<String> future = callable.futureCall("Is your refrigerator running?", callContext);
-
-    verify(tracerFactory, times(1)).newTracer(parentTracer, SPAN_NAME, OperationType.Unary);
-    verify(tracer, times(1)).attemptStarted(anyString(), anyInt());
-    verify(tracer, times(1)).attemptSucceeded();
-    verify(tracer, times(1)).operationSucceeded();
-    verifyNoMoreInteractions(tracer);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedClientStreamingCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedClientStreamingCallableTest.java
deleted file mode 100644
index cfee1c2a7..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedClientStreamingCallableTest.java
+++ /dev/null
@@ -1,210 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.ApiStreamObserver;
-import com.google.api.gax.rpc.CancelledException;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
-import java.util.List;
-import java.util.concurrent.CancellationException;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-@RunWith(JUnit4.class)
-public class TracedClientStreamingCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("fake-client", "fake-method");
-  public @Rule MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  private ApiTracer parentTracer = BaseApiTracer.getInstance();
-  @Mock private ApiTracer tracer;
-
-  private FakeClientCallable innerCallable;
-  private TracedClientStreamingCallable<String, String> tracedCallable;
-  private FakeStreamObserver outerResponseObsever;
-  private FakeCallContext callContext;
-
-  @Before
-  public void setUp() {
-    when(tracerFactory.newTracer(parentTracer, SPAN_NAME, OperationType.ClientStreaming))
-        .thenReturn(tracer);
-    innerCallable = new FakeClientCallable();
-    tracedCallable = new TracedClientStreamingCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-    outerResponseObsever = new FakeStreamObserver();
-    callContext = FakeCallContext.createDefault();
-  }
-
-  @Test
-  public void testTracerCreated() {
-    tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-
-    verify(tracerFactory, times(1))
-        .newTracer(parentTracer, SPAN_NAME, OperationType.ClientStreaming);
-  }
-
-  @Test
-  public void testCallContextPropagated() {
-    ImmutableMap<String, List<String>> extraHeaders =
-        ImmutableMap.<String, List<String>>of("header1", ImmutableList.of("value1"));
-
-    ApiCallContext newCallContext = callContext.withExtraHeaders(extraHeaders);
-    tracedCallable.clientStreamingCall(outerResponseObsever, newCallContext);
-
-    assertThat(innerCallable.callContext.getExtraHeaders()).isEqualTo(extraHeaders);
-  }
-
-  @Test
-  public void testOperationCancelled() {
-    ApiStreamObserver<String> clientStream =
-        tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-
-    clientStream.onError(new CancellationException("explicitly cancelled"));
-    innerCallable.responseObserver.onError(
-        new CancelledException(
-            "fake exception that would be generated by a client cancelling the rpc",
-            null,
-            FakeStatusCode.of(Code.CANCELLED),
-            false));
-
-    verify(tracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testOperationFinished() {
-    tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-    innerCallable.responseObserver.onNext("ignored");
-    innerCallable.responseObserver.onCompleted();
-
-    verify(tracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testOperationFailed() {
-    RuntimeException expectedError = new RuntimeException("fake error");
-    tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-    innerCallable.responseObserver.onError(expectedError);
-
-    verify(tracer, times(1)).operationFailed(expectedError);
-  }
-
-  @Test
-  public void testSyncError() {
-    RuntimeException expectedError = new RuntimeException("fake error");
-    innerCallable.syncError = expectedError;
-
-    try {
-      tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-    } catch (RuntimeException e) {
-      // noop
-    }
-
-    verify(tracer, times(1)).operationFailed(expectedError);
-  }
-
-  @Test
-  public void testRequestNotify() {
-    ApiStreamObserver<String> requestStream =
-        tracedCallable.clientStreamingCall(outerResponseObsever, callContext);
-
-    requestStream.onNext("request1");
-    requestStream.onNext("request2");
-    innerCallable.responseObserver.onNext("response");
-    innerCallable.responseObserver.onCompleted();
-
-    verify(tracer, times(2)).requestSent();
-    assertThat(outerResponseObsever.completed).isTrue();
-    assertThat(innerCallable.requestObserver.messages).containsExactly("request1", "request2");
-  }
-
-  private static class FakeClientCallable extends ClientStreamingCallable<String, String> {
-    private RuntimeException syncError;
-    private ApiStreamObserver<String> responseObserver;
-    // TODO: https://github.com/googleapis/gax-java/issues/687
-    private ApiCallContext callContext;
-    private FakeStreamObserver requestObserver;
-
-    @Override
-    public ApiStreamObserver<String> clientStreamingCall(
-        ApiStreamObserver<String> responseObserver, ApiCallContext context) {
-
-      if (syncError != null) {
-        throw syncError;
-      }
-
-      this.responseObserver = responseObserver;
-      this.callContext = context;
-      this.requestObserver = new FakeStreamObserver();
-
-      return this.requestObserver;
-    }
-  }
-
-  private static class FakeStreamObserver implements ApiStreamObserver<String> {
-    private List<String> messages = Lists.newArrayList();
-    private Throwable error;
-    private boolean completed;
-
-    @Override
-    public void onNext(String value) {
-      messages.add(value);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      error = t;
-      completed = true;
-    }
-
-    @Override
-    public void onCompleted() {
-      completed = true;
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedOperationCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedOperationCallableTest.java
deleted file mode 100644
index 80efd1f47..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedOperationCallableTest.java
+++ /dev/null
@@ -1,206 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.Mockito.reset;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.AbstractApiFuture;
-import com.google.api.core.ApiFuture;
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.longrunning.OperationFuture;
-import com.google.api.gax.longrunning.OperationSnapshot;
-import com.google.api.gax.retrying.RetryingFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-@RunWith(JUnit4.class)
-public class TracedOperationCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("FakeClient", "FakeOperation");
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  private ApiTracer parentTracer;
-  @Mock private ApiTracer tracer;
-  @Mock private OperationCallable<String, String, Long> innerCallable;
-  private FakeOperationFuture innerResult;
-
-  private TracedOperationCallable<String, String, Long> tracedOperationCallable;
-  private FakeCallContext callContext;
-
-  @Before
-  public void setUp() {
-    parentTracer = BaseApiTracer.getInstance();
-
-    // Wire the mock tracer factory
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.LongRunning)))
-        .thenReturn(tracer);
-
-    // Wire the mock inner callable
-    innerResult = new FakeOperationFuture();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-
-    // Build the system under test
-    tracedOperationCallable =
-        new TracedOperationCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-    callContext = FakeCallContext.createDefault();
-  }
-
-  @Test
-  public void testTracerCreated() {
-    tracedOperationCallable.futureCall("test", callContext);
-    verify(tracerFactory, times(1)).newTracer(parentTracer, SPAN_NAME, OperationType.LongRunning);
-  }
-
-  @Test
-  public void testOperationFinish() {
-    innerResult.set("successful result");
-    tracedOperationCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testOperationCancelled() {
-    innerResult.cancel(true);
-    tracedOperationCallable.futureCall("test", callContext);
-    verify(tracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testExternalOperationCancel() {
-    Mockito.reset(innerCallable, tracerFactory);
-
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.Unary)))
-        .thenReturn(tracer);
-
-    SettableApiFuture<Void> innerCancelResult = SettableApiFuture.create();
-    when(innerCallable.cancel(anyString(), any(ApiCallContext.class)))
-        .thenReturn(innerCancelResult);
-
-    tracedOperationCallable.cancel("some external operation", callContext);
-
-    verify(tracerFactory, times(1))
-        .newTracer(
-            parentTracer,
-            SpanName.of(SPAN_NAME.getClientName(), SPAN_NAME.getMethodName() + ".Cancel"),
-            OperationType.Unary);
-  }
-
-  @Test
-  public void testOperationFailed() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-    innerResult.setException(fakeError);
-    tracedOperationCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-
-  @Test
-  public void testSyncError() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-
-    // Reset the irrelevant expectations from setup. (only needed to silence the warnings).
-    @SuppressWarnings("unchecked")
-    OperationCallable<String, String, Long>[] innerCallableWrapper =
-        new OperationCallable[] {innerCallable};
-    reset(innerCallableWrapper);
-
-    when(innerCallable.futureCall(eq("failing test"), any(ApiCallContext.class)))
-        .thenThrow(fakeError);
-
-    try {
-      tracedOperationCallable.futureCall("failing test", callContext);
-    } catch (RuntimeException e) {
-      // ignored
-    }
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-
-  static class FakeOperationFuture extends AbstractApiFuture<String>
-      implements OperationFuture<String, Long> {
-    @Override
-    public boolean set(String value) {
-      return super.set(value);
-    }
-
-    @Override
-    public boolean setException(Throwable throwable) {
-      return super.setException(throwable);
-    }
-
-    @Override
-    public String getName() {
-      throw new UnsupportedOperationException("getInitialFuture() not implemented");
-    }
-
-    @Override
-    public ApiFuture<OperationSnapshot> getInitialFuture() {
-      throw new UnsupportedOperationException("getInitialFuture() not implemented");
-    }
-
-    @Override
-    public RetryingFuture<OperationSnapshot> getPollingFuture() {
-      throw new UnsupportedOperationException("getPollingFuture() not implemented");
-    }
-
-    @Override
-    public ApiFuture<Long> peekMetadata() {
-      throw new UnsupportedOperationException("getInitialFuture() not implemented");
-    }
-
-    @Override
-    public ApiFuture<Long> getMetadata() {
-      throw new UnsupportedOperationException("getInitialFuture() not implemented");
-    }
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedServerStreamingCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedServerStreamingCallableTest.java
deleted file mode 100644
index 660e525b5..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedServerStreamingCallableTest.java
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright 2019 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.doThrow;
-import static org.mockito.Mockito.eq;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.CancelledException;
-import com.google.api.gax.rpc.ResponseObserver;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.StatusCode.Code;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.rpc.testing.FakeStatusCode;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockResponseObserver;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCall;
-import com.google.api.gax.rpc.testing.MockStreamingApi.MockServerStreamingCallable;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-@RunWith(JUnit4.class)
-public class TracedServerStreamingCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("FakeClient", "FakeRpc");
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  @Mock private ApiTracer tracer;
-
-  private MockServerStreamingCallable<String, String> innerCallable;
-  private TracedServerStreamingCallable<String, String> tracedCallable;
-  private MockResponseObserver<String> responseObserver;
-  private ApiCallContext callContext;
-  @Mock private ApiTracer parentTracer;
-
-  @Before
-  public void setUp() {
-    // Wire the mock tracer factory
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.ServerStreaming)))
-        .thenReturn(tracer);
-    innerCallable = new MockServerStreamingCallable<>();
-
-    responseObserver = new MockResponseObserver<>(true);
-    callContext = FakeCallContext.createDefault().withTracer(parentTracer);
-
-    // Build the system under test
-    tracedCallable = new TracedServerStreamingCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-  }
-
-  @Test
-  public void testTracerCreated() {
-    tracedCallable.call("test", responseObserver, callContext);
-    verify(tracerFactory, times(1))
-        .newTracer(parentTracer, SPAN_NAME, OperationType.ServerStreaming);
-  }
-
-  @Test
-  public void testResponseNotify() {
-    tracedCallable.call("test", responseObserver, callContext);
-
-    MockServerStreamingCall<String, String> innerCall = innerCallable.popLastCall();
-    innerCall.getController().getObserver().onResponse("response1");
-    innerCall.getController().getObserver().onResponse("response2");
-
-    assertThat(responseObserver.popNextResponse()).isEqualTo("response1");
-    assertThat(responseObserver.popNextResponse()).isEqualTo("response2");
-    verify(tracer, times(2)).responseReceived();
-  }
-
-  @Test
-  public void testOperationCancelled() {
-    tracedCallable.call("test", responseObserver, callContext);
-    responseObserver.getController().cancel();
-
-    MockServerStreamingCall<String, String> innerCall = innerCallable.popLastCall();
-    innerCall
-        .getController()
-        .getObserver()
-        .onError(
-            new CancelledException("fake cancel", null, new FakeStatusCode(Code.CANCELLED), false));
-
-    assertThat(responseObserver.isDone()).isTrue();
-    verify(tracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testOperationFinish() {
-    tracedCallable.call("test", responseObserver, callContext);
-
-    MockServerStreamingCall<String, String> innerCall = innerCallable.popLastCall();
-    innerCall.getController().getObserver().onComplete();
-
-    assertThat(responseObserver.isDone()).isTrue();
-    verify(tracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testOperationFail() {
-    RuntimeException expectedError = new RuntimeException("expected error");
-
-    tracedCallable.call("test", responseObserver, callContext);
-
-    MockServerStreamingCall<String, String> innerCall = innerCallable.popLastCall();
-    innerCall.getController().getObserver().onError(expectedError);
-
-    assertThat(responseObserver.getFinalError()).isEqualTo(expectedError);
-    verify(tracer, times(1)).operationFailed(expectedError);
-  }
-
-  @Test
-  @SuppressWarnings("unchecked")
-  public void testSyncError() {
-    RuntimeException expectedError = new RuntimeException("expected error");
-
-    // Create a broken inner callable
-    ServerStreamingCallable<String, String> innerCallable = mock(ServerStreamingCallable.class);
-    doThrow(expectedError)
-        .when(innerCallable)
-        .call(
-            eq("test"),
-            (ResponseObserver<String>) any(ResponseObserver.class),
-            any(ApiCallContext.class));
-
-    // Recreate the tracedCallable using the new inner callable
-    tracedCallable = new TracedServerStreamingCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-
-    try {
-      tracedCallable.call("test", responseObserver, callContext);
-    } catch (RuntimeException e) {
-      // noop
-    }
-
-    verify(tracer, times(1)).operationFailed(expectedError);
-  }
-}
diff --git a/gax/src/test/java/com/google/api/gax/tracing/TracedUnaryCallableTest.java b/gax/src/test/java/com/google/api/gax/tracing/TracedUnaryCallableTest.java
deleted file mode 100644
index 9d066bdb4..000000000
--- a/gax/src/test/java/com/google/api/gax/tracing/TracedUnaryCallableTest.java
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * Copyright 2018 Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package com.google.api.gax.tracing;
-
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.anyString;
-import static org.mockito.Mockito.eq;
-import static org.mockito.Mockito.reset;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.google.api.core.SettableApiFuture;
-import com.google.api.gax.rpc.ApiCallContext;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.gax.rpc.testing.FakeCallContext;
-import com.google.api.gax.tracing.ApiTracerFactory.OperationType;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnit;
-import org.mockito.junit.MockitoRule;
-import org.mockito.quality.Strictness;
-
-@RunWith(JUnit4.class)
-public class TracedUnaryCallableTest {
-  private static final SpanName SPAN_NAME = SpanName.of("FakeClient", "FakeRpc");
-
-  @Rule
-  public final MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
-
-  @Mock private ApiTracerFactory tracerFactory;
-  private ApiTracer parentTracer;
-  @Mock private ApiTracer tracer;
-  @Mock private UnaryCallable<String, String> innerCallable;
-  private SettableApiFuture<String> innerResult;
-
-  private TracedUnaryCallable<String, String> tracedUnaryCallable;
-  private FakeCallContext callContext;
-
-  @Before
-  public void setUp() {
-    parentTracer = BaseApiTracer.getInstance();
-
-    // Wire the mock tracer factory
-    when(tracerFactory.newTracer(
-            any(ApiTracer.class), any(SpanName.class), eq(OperationType.Unary)))
-        .thenReturn(tracer);
-
-    // Wire the mock inner callable
-    innerResult = SettableApiFuture.create();
-    when(innerCallable.futureCall(anyString(), any(ApiCallContext.class))).thenReturn(innerResult);
-
-    // Build the system under test
-    tracedUnaryCallable = new TracedUnaryCallable<>(innerCallable, tracerFactory, SPAN_NAME);
-    callContext = FakeCallContext.createDefault();
-  }
-
-  @Test
-  public void testTracerCreated() {
-    tracedUnaryCallable.futureCall("test", callContext);
-    verify(tracerFactory, times(1)).newTracer(parentTracer, SPAN_NAME, OperationType.Unary);
-  }
-
-  @Test
-  public void testOperationFinish() {
-    innerResult.set("successful result");
-    tracedUnaryCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationSucceeded();
-  }
-
-  @Test
-  public void testOperationCancelled() {
-    innerResult.cancel(true);
-    tracedUnaryCallable.futureCall("test", callContext);
-    verify(tracer, times(1)).operationCancelled();
-  }
-
-  @Test
-  public void testOperationFailed() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-    innerResult.setException(fakeError);
-    tracedUnaryCallable.futureCall("test", callContext);
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-
-  @Test
-  public void testSyncError() {
-    RuntimeException fakeError = new RuntimeException("fake error");
-
-    // Reset the irrelevant expectations from setup. (only needed to silence the warnings).
-    @SuppressWarnings("unchecked")
-    UnaryCallable<String, String>[] innerCallableWrapper = new UnaryCallable[] {innerCallable};
-    reset(innerCallableWrapper);
-
-    when(innerCallable.futureCall(eq("failing test"), any(ApiCallContext.class)))
-        .thenThrow(fakeError);
-
-    try {
-      tracedUnaryCallable.futureCall("failing test", callContext);
-    } catch (RuntimeException e) {
-      // ignored
-    }
-
-    verify(tracer, times(1)).operationFailed(fakeError);
-  }
-}
diff --git a/gax/src/test/resources/com/google/api/gax/core/test.properties b/gax/src/test/resources/com/google/api/gax/core/test.properties
deleted file mode 100644
index 5f233db11..000000000
--- a/gax/src/test/resources/com/google/api/gax/core/test.properties
+++ /dev/null
@@ -1 +0,0 @@
-version=0.0.0
\ No newline at end of file
diff --git a/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem b/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem
deleted file mode 100644
index f95c93bcf..000000000
--- a/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtlsCertAndKey.pem
+++ /dev/null
@@ -1,30 +0,0 @@
------BEGIN CERTIFICATE-----
-MIICGzCCAYSgAwIBAgIIWrt6xtmHPs4wDQYJKoZIhvcNAQEFBQAwMzExMC8GA1UE
-AxMoMTAwOTEyMDcyNjg3OC5hcHBzLmdvb2dsZXVzZXJjb250ZW50LmNvbTAeFw0x
-MjEyMDExNjEwNDRaFw0yMjExMjkxNjEwNDRaMDMxMTAvBgNVBAMTKDEwMDkxMjA3
-MjY4NzguYXBwcy5nb29nbGV1c2VyY29udGVudC5jb20wgZ8wDQYJKoZIhvcNAQEB
-BQADgY0AMIGJAoGBAL1SdY8jTUVU7O4/XrZLYTw0ON1lV6MQRGajFDFCqD2Fd9tQ
-GLW8Iftx9wfXe1zuaehJSgLcyCxazfyJoN3RiONBihBqWY6d3lQKqkgsRTNZkdFJ
-Wdzl/6CxhK9sojh2p0r3tydtv9iwq5fuuWIvtODtT98EgphhncQAqkKoF3zVAgMB
-AAGjODA2MAwGA1UdEwEB/wQCMAAwDgYDVR0PAQH/BAQDAgeAMBYGA1UdJQEB/wQM
-MAoGCCsGAQUFBwMCMA0GCSqGSIb3DQEBBQUAA4GBAD8XQEqzGePa9VrvtEGpf+R4
-fkxKbcYAzqYq202nKu0kfjhIYkYSBj6gi348YaxE64yu60TVl42l5HThmswUheW4
-uQIaq36JvwvsDP5Zoj5BgiNSnDAFQp+jJFBRUA5vooJKgKgMDf/r/DCOsbO6VJF1
-kWwa9n19NFiV0z3m6isj
------END CERTIFICATE-----
------BEGIN PRIVATE KEY-----
-MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAL1SdY8jTUVU7O4/
-XrZLYTw0ON1lV6MQRGajFDFCqD2Fd9tQGLW8Iftx9wfXe1zuaehJSgLcyCxazfyJ
-oN3RiONBihBqWY6d3lQKqkgsRTNZkdFJWdzl/6CxhK9sojh2p0r3tydtv9iwq5fu
-uWIvtODtT98EgphhncQAqkKoF3zVAgMBAAECgYB51B9cXe4yiGTzJ4pOKpHGySAy
-sC1F/IjXt2eeD3PuKv4m/hL4l7kScpLx0+NJuQ4j8U2UK/kQOdrGANapB1ZbMZAK
-/q0xmIUzdNIDiGSoTXGN2mEfdsEpQ/Xiv0lyhYBBPC/K4sYIpHccnhSRQUZlWLLY
-lE5cFNKC9b7226mNvQJBAPt0hfCNIN0kUYOA9jdLtx7CE4ySGMPf5KPBuzPd8ty1
-fxaFm9PB7B76VZQYmHcWy8rT5XjoLJHrmGW1ZvP+iDsCQQDAvnKoarPOGb5iJfkq
-RrA4flf1TOlf+1+uqIOJ94959jkkJeb0gv/TshDnm6/bWn+1kJylQaKygCizwPwB
-Z84vAkA0Duur4YvsPJijoQ9YY1SGCagCcjyuUKwFOxaGpmyhRPIKt56LOJqpzyno
-fy8ReKa4VyYq4eZYT249oFCwMwIBAkAROPNF2UL3x5UbcAkznd1hLujtIlI4IV4L
-XUNjsJtBap7we/KHJq11XRPlniO4lf2TW7iji5neGVWJulTKS1xBAkAerktk4Hsw
-ErUaUG1s/d+Sgc8e/KMeBElV+NxGhcWEeZtfHMn/6VOlbzY82JyvC9OKC80A5CAE
-VUV6b25kqrcu
------END PRIVATE KEY-----
diff --git a/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtls_context_aware_metadata.json b/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtls_context_aware_metadata.json
deleted file mode 100644
index 62f10dd25..000000000
--- a/gax/src/test/resources/com/google/api/gax/rpc/mtls/mtls_context_aware_metadata.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "cert_provider_command": [
-    "some_binary",
-    "some_argument"
-  ],
-  "device_resource_ids": [
-    "123"
-  ]
-}
diff --git a/gax_java.bzl b/gax_java.bzl
deleted file mode 100644
index 83e11815c..000000000
--- a/gax_java.bzl
+++ /dev/null
@@ -1,85 +0,0 @@
-# Copyright 2019 Google LLC
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google LLC nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-def java_tests(name, srcs, runtime_deps, size):
-    classNames = []
-    for src in srcs:
-        # convert .java file path to fully qualified class name
-        className = src[(src.index("/com/") + 1):-5].replace("/", ".")
-        classNames.append(className)
-        native.java_test(
-            name = className,
-            test_class = className,
-            runtime_deps = runtime_deps,
-            size = size,
-        )
-    if classNames:
-        native.test_suite(
-            name = name,
-            tests = classNames,
-        )
-
-def google_java_format(name, srcs, formatter):
-    native.genrule(
-        name = name,
-        outs = ["%s.sh" % name],
-        srcs = srcs,
-        # TODO: this may fail if list of files is too long (exceeds max command line limit in shell).
-        #       Split the command into multiple executions if this ever fails (good enough for now)
-        cmd = "echo ' $(location %s) --replace $(SRCS)' > $@" % formatter,
-        executable = True,
-        tools = [formatter],
-        local = 1,
-    )
-
-def _google_java_format_verification_impl(ctx):
-    src_files = [src.path for src in ctx.files.srcs]
-    output_file = ctx.outputs.output_file
-    formatter = ctx.executable.formatter
-
-    ctx.actions.run_shell(
-        inputs = ctx.files.srcs,
-        arguments = ["--dry-run", "--set-exit-if-changed"] + src_files,
-        tools = [formatter],
-        command = "%s $@ > %s" % (formatter.path, output_file.path),
-        outputs = [output_file],
-        progress_message =
-            "If this target fails check the list of files that must be formatted in %s" % output_file.path,
-    )
-
-google_java_format_verification = rule(
-    attrs = {
-        "srcs": attr.label_list(allow_files = True),
-        "formatter": attr.label(
-            executable = True,
-            cfg = "host",
-        ),
-    },
-    outputs = {"output_file": "%{name}.txt"},
-    implementation = _google_java_format_verification_impl,
-)
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
deleted file mode 100644
index 943f0cbfa..000000000
Binary files a/gradle/wrapper/gradle-wrapper.jar and /dev/null differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
deleted file mode 100644
index f398c33c4..000000000
--- a/gradle/wrapper/gradle-wrapper.properties
+++ /dev/null
@@ -1,6 +0,0 @@
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
-networkTimeout=10000
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
deleted file mode 100755
index 65dcd68d6..000000000
--- a/gradlew
+++ /dev/null
@@ -1,244 +0,0 @@
-#!/bin/sh
-
-#
-# Copyright © 2015-2021 the original authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-##############################################################################
-#
-#   Gradle start up script for POSIX generated by Gradle.
-#
-#   Important for running:
-#
-#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
-#       noncompliant, but you have some other compliant shell such as ksh or
-#       bash, then to run this script, type that shell name before the whole
-#       command line, like:
-#
-#           ksh Gradle
-#
-#       Busybox and similar reduced shells will NOT work, because this script
-#       requires all of these POSIX shell features:
-#         * functions;
-#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
-#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
-#         * compound commands having a testable exit status, especially «case»;
-#         * various built-in commands including «command», «set», and «ulimit».
-#
-#   Important for patching:
-#
-#   (2) This script targets any POSIX shell, so it avoids extensions provided
-#       by Bash, Ksh, etc; in particular arrays are avoided.
-#
-#       The "traditional" practice of packing multiple parameters into a
-#       space-separated string is a well documented source of bugs and security
-#       problems, so this is (mostly) avoided, by progressively accumulating
-#       options in "$@", and eventually passing that to Java.
-#
-#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
-#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
-#       see the in-line comments for details.
-#
-#       There are tweaks for specific operating systems such as AIX, CygWin,
-#       Darwin, MinGW, and NonStop.
-#
-#   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
-#       within the Gradle project.
-#
-#       You can find Gradle at https://github.com/gradle/gradle/.
-#
-##############################################################################
-
-# Attempt to set APP_HOME
-
-# Resolve links: $0 may be a link
-app_path=$0
-
-# Need this for daisy-chained symlinks.
-while
-    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
-    [ -h "$app_path" ]
-do
-    ls=$( ls -ld "$app_path" )
-    link=${ls#*' -> '}
-    case $link in             #(
-      /*)   app_path=$link ;; #(
-      *)    app_path=$APP_HOME$link ;;
-    esac
-done
-
-# This is normally unused
-# shellcheck disable=SC2034
-APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
-
-# Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD=maximum
-
-warn () {
-    echo "$*"
-} >&2
-
-die () {
-    echo
-    echo "$*"
-    echo
-    exit 1
-} >&2
-
-# OS specific support (must be 'true' or 'false').
-cygwin=false
-msys=false
-darwin=false
-nonstop=false
-case "$( uname )" in                #(
-  CYGWIN* )         cygwin=true  ;; #(
-  Darwin* )         darwin=true  ;; #(
-  MSYS* | MINGW* )  msys=true    ;; #(
-  NONSTOP* )        nonstop=true ;;
-esac
-
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
-
-
-# Determine the Java command to use to start the JVM.
-if [ -n "$JAVA_HOME" ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-        # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD=$JAVA_HOME/jre/sh/java
-    else
-        JAVACMD=$JAVA_HOME/bin/java
-    fi
-    if [ ! -x "$JAVACMD" ] ; then
-        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
-else
-    JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-fi
-
-# Increase the maximum file descriptors if we can.
-if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
-    case $MAX_FD in #(
-      max*)
-        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045 
-        MAX_FD=$( ulimit -H -n ) ||
-            warn "Could not query maximum file descriptor limit"
-    esac
-    case $MAX_FD in  #(
-      '' | soft) :;; #(
-      *)
-        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045 
-        ulimit -n "$MAX_FD" ||
-            warn "Could not set maximum file descriptor limit to $MAX_FD"
-    esac
-fi
-
-# Collect all arguments for the java command, stacking in reverse order:
-#   * args from the command line
-#   * the main class name
-#   * -classpath
-#   * -D...appname settings
-#   * --module-path (only if needed)
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
-
-# For Cygwin or MSYS, switch paths to Windows format before running java
-if "$cygwin" || "$msys" ; then
-    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
-
-    JAVACMD=$( cygpath --unix "$JAVACMD" )
-
-    # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    for arg do
-        if
-            case $arg in                                #(
-              -*)   false ;;                            # don't mess with options #(
-              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
-                    [ -e "$t" ] ;;                      #(
-              *)    false ;;
-            esac
-        then
-            arg=$( cygpath --path --ignore --mixed "$arg" )
-        fi
-        # Roll the args list around exactly as many times as the number of
-        # args, so each arg winds up back in the position where it started, but
-        # possibly modified.
-        #
-        # NB: a `for` loop captures its iteration list before it begins, so
-        # changing the positional parameters here affects neither the number of
-        # iterations, nor the values presented in `arg`.
-        shift                   # remove old arg
-        set -- "$@" "$arg"      # push replacement arg
-    done
-fi
-
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
-
-set -- \
-        "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
-        org.gradle.wrapper.GradleWrapperMain \
-        "$@"
-
-# Stop when "xargs" is not available.
-if ! command -v xargs >/dev/null 2>&1
-then
-    die "xargs is not available"
-fi
-
-# Use "xargs" to parse quoted args.
-#
-# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
-#
-# In Bash we could simply go:
-#
-#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
-#   set -- "${ARGS[@]}" "$@"
-#
-# but POSIX shell has neither arrays nor command substitution, so instead we
-# post-process each arg (as a line of input to sed) to backslash-escape any
-# character that might be a shell metacharacter, then use eval to reverse
-# that process (while maintaining the separation between arguments), and wrap
-# the whole thing up as a single "set" statement.
-#
-# This will of course break if any of these variables contains a newline or
-# an unmatched quote.
-#
-
-eval "set -- $(
-        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
-        xargs -n1 |
-        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
-        tr '\n' ' '
-    )" '"$@"'
-
-exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
deleted file mode 100644
index 6689b85be..000000000
--- a/gradlew.bat
+++ /dev/null
@@ -1,92 +0,0 @@
-@rem
-@rem Copyright 2015 the original author or authors.
-@rem
-@rem Licensed under the Apache License, Version 2.0 (the "License");
-@rem you may not use this file except in compliance with the License.
-@rem You may obtain a copy of the License at
-@rem
-@rem      https://www.apache.org/licenses/LICENSE-2.0
-@rem
-@rem Unless required by applicable law or agreed to in writing, software
-@rem distributed under the License is distributed on an "AS IS" BASIS,
-@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@rem See the License for the specific language governing permissions and
-@rem limitations under the License.
-@rem
-
-@if "%DEBUG%"=="" @echo off
-@rem ##########################################################################
-@rem
-@rem  Gradle startup script for Windows
-@rem
-@rem ##########################################################################
-
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
-
-set DIRNAME=%~dp0
-if "%DIRNAME%"=="" set DIRNAME=.
-@rem This is normally unused
-set APP_BASE_NAME=%~n0
-set APP_HOME=%DIRNAME%
-
-@rem Resolve any "." and ".." in APP_HOME to make it shorter.
-for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
-
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
-
-@rem Find java.exe
-if defined JAVA_HOME goto findJavaFromJavaHome
-
-set JAVA_EXE=java.exe
-%JAVA_EXE% -version >NUL 2>&1
-if %ERRORLEVEL% equ 0 goto execute
-
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto execute
-
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:execute
-@rem Setup the command line
-
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-
-
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
-
-:end
-@rem End local scope for the variables with windows NT shell
-if %ERRORLEVEL% equ 0 goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-set EXIT_CODE=%ERRORLEVEL%
-if %EXIT_CODE% equ 0 set EXIT_CODE=1
-if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
-exit /b %EXIT_CODE%
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
diff --git a/java.header b/java.header
deleted file mode 100644
index 0ae9545db..000000000
--- a/java.header
+++ /dev/null
@@ -1,29 +0,0 @@
-^/\*$
-^ \* Copyright 20\d\d Google LLC$
-^ \*$
-^ \* Redistribution and use in source and binary forms, with or without$
-^ \* modification, are permitted provided that the following conditions are$
-^ \* met:$
-^ \*$
-^ \*     \* Redistributions of source code must retain the above copyright$
-^ \* notice, this list of conditions and the following disclaimer.$
-^ \*     \* Redistributions in binary form must reproduce the above$
-^ \* copyright notice, this list of conditions and the following disclaimer$
-^ \* in the documentation and/or other materials provided with the$
-^ \* distribution.$
-^ \*     \* Neither the name of Google LLC nor the names of its$
-^ \* contributors may be used to endorse or promote products derived from$
-^ \* this software without specific prior written permission.$
-^ \*$
-^ \* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS$
-^ \* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT$
-^ \* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR$
-^ \* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT$
-^ \* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,$
-^ \* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES \(INCLUDING, BUT NOT$
-^ \* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,$
-^ \* DATA, OR PROFITS; OR BUSINESS INTERRUPTION\) HOWEVER CAUSED AND ON ANY$
-^ \* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT$
-^ \* \(INCLUDING NEGLIGENCE OR OTHERWISE\) ARISING IN ANY WAY OUT OF THE USE$
-^ \* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.$
-^ \*/$
\ No newline at end of file
diff --git a/license-checks.xml b/license-checks.xml
deleted file mode 100644
index 362833222..000000000
--- a/license-checks.xml
+++ /dev/null
@@ -1,10 +0,0 @@
-<?xml version="1.0"?>
-<!DOCTYPE module PUBLIC
-  "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
-  "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
-<module name="Checker">
-  <module name="RegexpHeader">
-    <property name="fileExtensions" value="java"/>
-    <property name="headerFile" value="java.header"/>
-  </module>
-</module>
\ No newline at end of file
diff --git a/license-header-javadoc.txt b/license-header-javadoc.txt
deleted file mode 100644
index d31410dc3..000000000
--- a/license-header-javadoc.txt
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright 20xx Google LLC
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google LLC nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
diff --git a/pom.xml b/pom.xml
deleted file mode 100644
index 45cb918c6..000000000
--- a/pom.xml
+++ /dev/null
@@ -1,285 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-  <groupId>com.google.api</groupId>
-  <artifactId>gax-parent</artifactId>
-  <packaging>pom</packaging>
-  <version>2.20.1</version><!-- {x-version-update:gax:current} -->
-  <name>GAX (Google Api eXtensions) for Java (Parent)</name>
-  <url>https://github.com/googleapis/gax-java</url>
-  <description>Google Api eXtensions for Java (Parent)</description>
-
-  <parent>
-    <groupId>com.google.cloud</groupId>
-    <artifactId>google-cloud-shared-config</artifactId>
-    <version>1.5.5</version>
-  </parent>
-
-  <developers>
-    <developer>
-      <id>GoogleAPIs</id>
-      <name>GoogleAPIs</name>
-      <email>googleapis@googlegroups.com</email>
-      <organization>Google LLC</organization>
-      <organizationUrl>https://www.google.com</organizationUrl>
-    </developer>
-  </developers>
-
-  <scm>
-    <connection>scm:git:https://github.com/googleapis/gax-java.git</connection>
-    <url>https://github.com/googleapis/gax-java</url>
-  </scm>
-
-  <licenses>
-    <license>
-      <name>BSD</name>
-      <url>https://github.com/googleapis/gax-java/blob/master/LICENSE</url>
-    </license>
-  </licenses>
-
-  <properties>
-    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.source>1.8</maven.compiler.source>
-    <maven.compiler.target>1.8</maven.compiler.target>
-    <auto-value.version>1.10.1</auto-value.version>
-  </properties>
-
-  <modules>
-    <module>gax</module>
-    <module>gax-grpc</module>
-    <module>gax-httpjson</module>
-    <module>gax-bom</module>
-  </modules>
-
-  <dependencyManagement>
-    <dependencies>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>api-common</artifactId>
-        <version>2.3.1</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.auth</groupId>
-        <artifactId>google-auth-library-credentials</artifactId>
-        <version>1.14.0</version>
-      </dependency>
-      <dependency>
-        <groupId>org.threeten</groupId>
-        <artifactId>threetenbp</artifactId>
-        <version>1.6.5</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.auth</groupId>
-        <artifactId>google-auth-library-oauth2-http</artifactId>
-        <version>1.14.0</version>
-        <exclusions>
-          <exclusion>
-            <groupId>com.google.errorprone</groupId>
-            <artifactId>error_prone_annotations</artifactId>
-          </exclusion>
-        </exclusions>
-      </dependency>
-      <dependency>
-        <groupId>com.google.code.findbugs</groupId>
-        <artifactId>jsr305</artifactId>
-        <version>3.0.2</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.guava</groupId>
-        <artifactId>guava</artifactId>
-        <version>31.1-jre</version>
-        <exclusions>
-          <exclusion>
-            <groupId>com.google.errorprone</groupId>
-            <artifactId>error_prone_annotations</artifactId>
-          </exclusion>
-        </exclusions>
-      </dependency>
-      <dependency>
-        <groupId>io.opencensus</groupId>
-        <artifactId>opencensus-api</artifactId>
-        <version>0.31.1</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.auto.value</groupId>
-        <artifactId>auto-value-annotations</artifactId>
-        <version>${auto-value.version}</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.auto.value</groupId>
-        <artifactId>auto-value</artifactId>
-        <version>${auto-value.version}</version>
-      </dependency>
-      <dependency>
-        <groupId>junit</groupId>
-        <artifactId>junit</artifactId>
-        <version>4.13.2</version>
-      </dependency>
-      <dependency>
-        <groupId>org.mockito</groupId>
-        <artifactId>mockito-core</artifactId>
-        <version>4.11.0</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax</artifactId>
-        <version>2.20.1</version> <!-- {x-version-update:gax:current} -->
-      </dependency>
-      <dependency>
-        <groupId>com.google.api</groupId>
-        <artifactId>gax</artifactId>
-        <version>2.20.1</version> <!-- {x-version-update:gax:current} -->
-        <type>test-jar</type>
-        <classifier>testlib</classifier>
-      </dependency>
-      <dependency>
-        <groupId>com.google.api.grpc</groupId>
-        <artifactId>proto-google-common-protos</artifactId>
-        <version>2.11.0</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.api.grpc</groupId>
-        <artifactId>grpc-google-common-protos</artifactId>
-        <version>2.11.0</version>
-      </dependency>
-      <dependency>
-        <groupId>io.grpc</groupId>
-        <artifactId>grpc-bom</artifactId>
-        <version>1.51.1</version>
-        <type>pom</type>
-        <scope>import</scope>
-      </dependency>
-      <dependency>
-        <groupId>com.google.code.gson</groupId>
-        <artifactId>gson</artifactId>
-        <version>2.10</version>
-      </dependency>
-      <dependency>
-        <groupId>org.graalvm.sdk</groupId>
-        <artifactId>graal-sdk</artifactId>
-        <version>22.3.0</version>
-      </dependency>
-      <dependency>
-        <groupId>com.google.http-client</groupId>
-        <artifactId>google-http-client-bom</artifactId>
-        <version>1.42.3</version>
-        <type>pom</type>
-        <scope>import</scope>
-      </dependency>
-      <dependency>
-        <groupId>com.google.protobuf</groupId>
-        <artifactId>protobuf-bom</artifactId>
-        <version>3.21.12</version>
-        <type>pom</type>
-        <scope>import</scope>
-      </dependency>
-    </dependencies>
-  </dependencyManagement>
-
-  <!-- Test Dependencies -->
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.google.truth</groupId>
-      <artifactId>truth</artifactId>
-      <version>1.1.3</version>
-      <exclusions>
-        <exclusion>
-          <groupId>org.checkerframework</groupId>
-          <artifactId>checker-qual</artifactId>
-        </exclusion>
-        <exclusion>
-          <groupId>com.google.errorprone</groupId>
-          <artifactId>error_prone_annotations</artifactId>
-        </exclusion>
-      </exclusions>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <resources>
-      <resource>
-        <directory>src/main/resources</directory>
-        <filtering>true</filtering>
-      </resource>
-    </resources>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration>
-          <annotationProcessorPaths>
-            <path>
-              <groupId>com.google.auto.value</groupId>
-              <artifactId>auto-value</artifactId>
-              <version>${auto-value.version}</version>
-            </path>
-          </annotationProcessorPaths>
-          <release>8</release>
-          <compilerArgs>
-            <arg>-Xlint:unchecked</arg>
-            <arg>-Xlint:deprecation</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <executions>
-          <execution>
-            <goals>
-              <goal>test-jar</goal>
-            </goals>
-            <configuration>
-              <skip>true</skip>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>com.coveo</groupId>
-        <artifactId>fmt-maven-plugin</artifactId>
-        <executions>
-          <execution>
-            <phase>validate</phase>
-            <goals>
-              <goal>check</goal>
-            </goals>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
-
-  <profiles>
-    <profile>
-      <!-- profile for nexus-staging:release invocation -->
-      <id>release-staging-repository</id>
-      <build>
-        <plugins>
-          <plugin>
-            <!-- The root project runs nexus-staging:release task -->
-            <groupId>org.sonatype.plugins</groupId>
-            <artifactId>nexus-staging-maven-plugin</artifactId>
-            <version>1.6.13</version>
-            <extensions>true</extensions>
-            <configuration>
-              <serverId>sonatype-nexus-staging</serverId>
-              <nexusUrl>https://google.oss.sonatype.org/</nexusUrl>
-              <autoReleaseAfterClose>false</autoReleaseAfterClose>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
-  </profiles>
-</project>
\ No newline at end of file
diff --git a/renovate.json b/renovate.json
deleted file mode 100644
index 930f87aab..000000000
--- a/renovate.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "enabled": false,
-  "extends": [
-    "config:base"
-  ],
-  "ignorePaths": [".kokoro/requirements.txt"],
-  "regexManagers": [
-    {
-      "fileMatch": ["^dependencies\\.properties$"],
-      "matchStrings": ["=(?<depName>.*?):(?<currentValue>.*?)\\n"],
-      "datasourceTemplate": "maven"
-    },
-    {
-      "fileMatch": ["^dependencies\\.properties$"],
-      "matchStrings": ["version\\.com_google_protobuf=(?<currentValue>.*?)\\n"],
-      "depNameTemplate": "com.google.protobuf:protobuf-java",
-      "datasourceTemplate": "maven"
-    },
-    {
-      "fileMatch": ["^dependencies\\.properties$"],
-      "matchStrings": ["version\\.google_java_format=(?<currentValue>.*?)\\n"],
-      "depNameTemplate": "com.google.googlejavaformat:google-java-format",
-      "datasourceTemplate": "maven"
-    },
-    {
-      "fileMatch": ["^dependencies\\.properties$"],
-      "matchStrings": ["version\\.io_grpc=(?<currentValue>.*?)\\n"],
-      "depNameTemplate": "io.grpc:grpc-core",
-      "datasourceTemplate": "maven"
-    }
-  ]
-}
diff --git a/repositories.bzl b/repositories.bzl
deleted file mode 100644
index 4231c5790..000000000
--- a/repositories.bzl
+++ /dev/null
@@ -1,149 +0,0 @@
-# Copyright 2019 Google LLC
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google LLC nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-load("@bazel_tools//tools/build_defs/repo:jvm.bzl", "jvm_maven_import_external")
-load("@com_google_api_gax_java_properties//:dependencies.properties.bzl", "PROPERTIES")
-
-def com_google_api_gax_java_repositories():
-    # Import dependencies shared between Gradle and Bazel (i.e. maven dependencies)
-    for name, artifact in PROPERTIES.items():
-        _maybe(
-            jvm_maven_import_external,
-            name = name,
-            strip_repo_prefix = "maven.",
-            artifact = _fix_bazel_artifact_format(artifact),
-            server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-            licenses = ["notice", "reciprocal"],
-        )
-
-    # Import Bazel-only dependencies (Gradle version will import maven artifacts of same
-    # version, while Bazel will depend on Bazel workspaces). The versions are shared in the
-    # properties file.
-
-    _protobuf_version = PROPERTIES["version.com_google_protobuf"]
-    _protobuf_version_in_link = "v%s" % _protobuf_version
-    _maybe(
-        http_archive,
-        name = "com_google_protobuf",
-        urls = ["https://github.com/protocolbuffers/protobuf/archive/%s.zip" % _protobuf_version_in_link],
-        strip_prefix = "protobuf-%s" % _protobuf_version,
-    )
-
-    _grpc_version = PROPERTIES["version.io_grpc"]
-    _grpc_version_in_link = "v%s" % _grpc_version
-    _maybe(
-        http_archive,
-        name = "io_grpc_grpc_java",
-        urls = ["https://github.com/grpc/grpc-java/archive/%s.zip" % _grpc_version_in_link],
-        strip_prefix = "grpc-java-%s" % _grpc_version,
-    )
-
-    _bazel_skylib_version = "1.0.3"
-    _maybe(
-        http_archive,
-        name = "bazel_skylib",
-        strip_prefix = "bazel-skylib-%s" % _bazel_skylib_version,
-        urls = ["https://github.com/bazelbuild/bazel-skylib/archive/%s.zip" % _bazel_skylib_version],
-    )
-
-    _maybe(
-        jvm_maven_import_external,
-        name = "com_google_protobuf_java_util",
-        artifact = "com.google.protobuf:protobuf-java-util:%s" % PROPERTIES["version.com_google_protobuf"],
-        server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-        licenses = ["notice", "reciprocal"],
-    )
-
-    _maybe(
-        jvm_maven_import_external,
-        name = "com_google_protobuf_java",
-        artifact = "com.google.protobuf:protobuf-java:%s" % PROPERTIES["version.com_google_protobuf"],
-        server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-        licenses = ["notice", "reciprocal"],
-    )
-
-    _maybe(
-        jvm_maven_import_external,
-        name = "io_grpc_grpc_netty_shaded",
-        artifact = "io.grpc:grpc-netty-shaded:%s" % PROPERTIES["version.io_grpc"],
-        server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-        licenses = ["notice", "reciprocal"],
-    )
-
-    _maybe(
-        jvm_maven_import_external,
-        name = "io_grpc_grpc_grpclb",
-        artifact = "io.grpc:grpc-grpclb:%s" % PROPERTIES["version.io_grpc"],
-        server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-        licenses = ["notice", "reciprocal"],
-    )
-
-    _maybe(
-        jvm_maven_import_external,
-        name = "google_java_format_all_deps",
-        artifact = "com.google.googlejavaformat:google-java-format:jar:all-deps:%s" % PROPERTIES["version.google_java_format"],
-        server_urls = ["https://repo.maven.apache.org/maven2/", "http://repo1.maven.org/maven2/"],
-        licenses = ["notice", "reciprocal"],
-    )
-
-    _maybe(
-        native.bind,
-        name = "guava",
-        actual = "@com_google_guava_guava//jar",
-    )
-
-    _maybe(
-        native.bind,
-        name = "gson",
-        actual = "@com_google_code_gson_gson//jar",
-    )
-
-    _maybe(
-        native.bind,
-        name = "error_prone_annotations",
-        actual = "@com_google_errorprone_error_prone_annotations//jar",
-    )
-
-def _maybe(repo_rule, name, strip_repo_prefix = "", **kwargs):
-    if not name.startswith(strip_repo_prefix):
-        return
-    repo_name = name[len(strip_repo_prefix):]
-    if repo_name in native.existing_rules():
-        return
-    repo_rule(name = repo_name, **kwargs)
-
-def _fix_bazel_artifact_format(artifact_id):
-    # Fix the artifact id format discrepancy between Bazel & Gradle.
-    # This is relevant only when classifier is specified explicitly.
-    # Bazel format:  groupId:artifactId:jar:classifier:version
-    # Gradle format: groupId:artifactId:version:classifier
-    ids = artifact_id.split(":")
-    if len(ids) != 4:
-        return artifact_id
-    return "%s:%s:%s:%s:%s" % (ids[0], ids[1], "jar", ids[3], ids[2])
diff --git a/repository_rules.bzl b/repository_rules.bzl
deleted file mode 100644
index 5c62c23c0..000000000
--- a/repository_rules.bzl
+++ /dev/null
@@ -1,65 +0,0 @@
-# Copyright 2019 Google LLC
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google LLC nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-def _com_google_api_gax_java_properties_impl(ctx):
-    props_path = ctx.path(ctx.attr.file)
-    result = ctx.execute(["cat", props_path])
-
-    if result.return_code != 0:
-        fail("Could not load dependencies from properties file, error_code %s" + str(result.return_code))
-
-    props = result.stdout.splitlines()
-    props_as_map = {}
-
-    for prop in props:
-        p = prop.strip()
-        if len(p) <= 0 or p.startswith("#"):
-            continue
-        key_value = p.split("=", 1)
-        props_as_map[key_value[0]] = key_value[1]
-
-    props_name = ctx.attr.file.name
-    dependencies_bzl = """
-# DO NOT EDIT. This file was generated from {properties_file}.
-PROPERTIES = {props_as_map}
-     """.format(
-        properties_file = props_name,
-        props_as_map = str(props_as_map),
-     )
-    ctx.file("BUILD.bazel", "")
-    ctx.file("%s.bzl" % props_name, dependencies_bzl)
-
-
-com_google_api_gax_java_properties = repository_rule(
-    implementation = _com_google_api_gax_java_properties_impl,
-    attrs = {
-        "file": attr.label(),
-    },
-    local = True,
-)
-
diff --git a/settings.gradle b/settings.gradle
deleted file mode 100644
index 52f23d4bf..000000000
--- a/settings.gradle
+++ /dev/null
@@ -1,4 +0,0 @@
-include "gax"
-include "gax-bom"
-include "gax-grpc"
-include "gax-httpjson"
diff --git a/versions.txt b/versions.txt
deleted file mode 100644
index 35a770fde..000000000
--- a/versions.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-# Format:
-# module:released-version:current-version
-
-gax:2.20.1:2.20.1
-gax-bom:2.20.1:2.20.1
-gax-grpc:2.20.1:2.20.1
-gax-httpjson:0.105.1:0.105.1