def test_unexpectedSuccess(self):
        """
        A test which is marked as todo but succeeds will have an unexpected
        success reported to its result. A test run is still successful even
        when this happens.
        """
        self.result.addUnexpectedSuccess(self.test, makeTodo("Heya!"))
        self.assertEqual(True, self.result.wasSuccessful())
        self.assertEqual(len(self._getUnexpectedSuccesses(self.result)), 1)

        A test which is marked as todo but succeeds will have an unexpected
        success reported to its result. A test run is still successful even
        when this happens.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_reporter.py