got AttributeError while using "with client.get(...) as response"

[jiunjiunma]

Hi,
I am following the example in your documentation to change the response status. My code looks like something this:
with self.client.post(url, data, ...) as response:
if response.status_code == 200 or response.status_code == 401:
response.success()

However, I keep getting the following python errors while running it. It seems the __exit__ method was not found so the "with" syntax wouldn't work. 

Not sure if it's a bug or anything else I have to do to make it work. Your help will be really appreciated.

Thanks,
--Jiunjiun

[2014-06-18 10:07:46,757] jma/ERROR/stderr: Traceback (most recent call last):
File "/Library/Python/2.7/site-packages/locust/core.py", line 267, in run
self.execute_next_task()
File "/Library/Python/2.7/site-packages/locust/core.py", line 293, in execute_next_task
self.execute_task(task["callable"], _task["args"], *_task["kwargs"])
File "/Library/Python/2.7/site-packages/locust/core.py", line 305, in execute_task
task(self, _args, *_kwargs)
File "/Users/jma/PycharmProjects/locust/rtc-register.py", line 52, in generate_account_token_form_post
self.validate_credential(username, password)
File "/Users/jma/PycharmProjects/locust/rtc-register.py", line 69, in validate_credential
with self.client.post(url, data, headers = {'content-type': 'application/json'}) as response:
AttributeError: exit

[heyman]

In order to make Locust's HTTP client return a context manager (that can be used with the with statement), you must add catch_response=True to the arguments. Like this:

with self.client.post("/some/url", data, catch_response=True) as response:
    if response.status_code == 401:
        response.success()

For more info, see the documentation: http://docs.locust.io/en/latest/writing-a-locustfile.html#manually-controlling-if-a-request-should-be-considered-successful-or-a-failure