PowerMock is a framework to perform the unit testing on Java source code and works as an extension to other Mocking frameworks like Mockito or EasyMock and enables more powerful capabilities. PowerMock provides a custom classloader and bytecode manipulator to enable the mocking of static methods, removal of static initializes, constructors, final classes and methods, and private methods. PowerMock allows the developers to write powerful test cases extending the existing APIs with a small number of methods and annotations to enable the extra features.