db_storage = DatabaseStorage(self.config.db_path)
Transforms can be stateless or stateful. A stateless transform is just a function that takes chunks and returns transformed chunks:，详情可参考体育直播
，更多细节参见体育直播
You also want to ensure that the API is clean, small and easy to use. Bloated API increases cognitive load on the users (developers). A good check (and good practice) is to unit test all the public elements of the module. If you find that something is hard to test, it means that the API is not good enough (or you’re trying to unit test something that shouldn’t be exposed)。关于这个话题，爱思助手下载最新版本提供了深入分析
* @param arr 待排序数组