Unknown reply code 312

[sergey-netdev]

Describe the bug

When I call the following code with invalid (non existing queue) routingKey

                channel.BasicPublish(
                    exchange: _exchange,
                    routingKey: _key,
                    basicProperties: null,
                    mandatory: true,
                    body: message.Payload);

I get code 312 in BasicReturn event handler's args.ReplyCode and "NO_ROUTE" as a message. There is no such code in RabbitMQ.Client.Constants class, the closest is RabbitMQ.Client.Constants.NoConsumers which is 313.

Reproduction steps

Use .NET RabbitMQ.Client nuget version 6.5.0
Use IModel.BasicPublish() and subscribe to IModel.BasicReturn event handler
See 312 reply code when the handler is triggered

Expected behavior

313 reply code so I can use RabbitMQ.Client.Constants.NoConsumers in my tests

Additional context

No response