Both projects introduced earlier do not cover all types of methods or fields. Depending on the applied modifiers, such as static or final, a class, method, or field, can be out of range for Mockito or EasyMock. In such cases, we can use PowerMock to extend the mocking framework. This way, we can mock objects that can only be mocked in a tricky manner. However, one should be cautious with PowerMock since the necessity to use many of the features it provides is usually a sign of poor design. If you're working on a legacy code, PowerMock might be a good choice. Otherwise, try to design your code in such a way that PowerMock is not needed. We'll show you how to do that later on.

For more information, visit https://code.google.com/p/powermock/.