@Override
              public DraweeHierarchy answer(InvocationOnMock invocation) throws Throwable {
                return mockDraweeHierarchy();
              }
Creates a mock GenericDraweeHierarchyBuilder that builds a new DH instance each time.

@return mock GenericDraweeHierarchyBuilder
drawee/src/test/java/com/facebook/drawee/testing/DraweeMocks.java