What is Power Mockito?

PowerMock is a Java framework that extends Mockito (and EasyMock) to enable mocking of static methods, constructors, final classes and methods, private methods, and removal of static initializers. It's commonly used when legacy code or third-party libraries make unit testing difficult due to tight coupling and non-testable designs. However, it's generally recommended to refactor code to be more testable rather than relying heavily on PowerMock, as its use can make tests more complex and brittle.