说明：  测试驱动开发(TDD)以测试作为开发过程的中心，它要求在编写任何产品代码之前， 首先编写用于定义产品代码行为的测试，而编写的产品代码又要以使测试通过为目的。 测试驱动开发要求测试可以完全自动化的运行，在对代码进行重构前后必须运行测试。这是一种革命性的开发方法， 能够造就简单、清晰、高质量的代码。
(test-driven development (TDD) to test as the center of the development process, It requires the preparation of any product code, first used in the preparation of product code definition of the test, and the preparation of the products we need to make code adopted for the purpose of testing. Test-driven development requirements can be fully automated test the operation of the code of conduct must be running before and after Reconstruction tests. This is a revolutionary development method to create a simple, clear, high-quality code.)