def test_standardLibraryCompatibilitySuccess(self):
        """
        Tests that use the standard library C{expectedFailure} feature worth
        with Trial reporters.
        """
        class Test(StdlibTestCase):
            @expectedFailure
            def test_success(self):
                pass

        test = Test('test_success')
        test.run(self.result)
        self.assertEqual(len(self._getUnexpectedSuccesses(self.result)), 1)

        Tests that use the standard library C{expectedFailure} feature worth
        with Trial reporters.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_reporter.py