You will also want to test for any objects you need, and you may even want to test for the existence of identified elements you need as hooks for your script.
你可能还想测试所有需要的对象，甚至还想测试用作脚本钩子的标识元素是否存在。
2
To do this, we'll assume the existence of a test factory.
要做到这一点，我们假定已经存在一个测试工厂。
3
The existence of working code is a wonderful thing for setting up a test suite that defines what the problem you want to solve is, exactly.