Method annotation used to invert test case results. If a JUnit 3/4 test case method is
annotated with @NotYetImplemented the test will fail if no test failure occurs and it will pass
if a test failure occurs.
This is helpful for tests that don't currently work but should work one day, when the tested functionality has been implemented.
The idea for this AST transformation originated in GroovyTestCase.notYetImplemented.