To contribute to pika, please make sure that any new features or changes to existing functionality include test coverage.
Pull requests that add or change code without coverage will most likely be rejected.
Additionally, please format your code using yapf <http://pypi.python.org/pypi/yapf>_
with google style prior to issuing your pull request.
为了完善Pika，请确保任何新功能或变更 对现有功能的更改包括测试。
合并请求包含添加或更改代码，而覆盖将最有可能被拒绝。
此外，请使用yapf格式化代码<http://pypi.python.org/pypi/yapf>_
发出合并求的代码要求符合google风格。