def test_inheritance(self):
        """
        Test that we can inherit L{log.PythonLoggingObserver} and use super:
        that's basically a validation that L{log.PythonLoggingObserver} is
        new-style class.
        """
        class MyObserver(log.PythonLoggingObserver):
            def emit(self, eventDict):
                super(MyObserver, self).emit(eventDict)
        obs = MyObserver()
        l = []
        oldEmit = log.PythonLoggingObserver.emit
        try:
            log.PythonLoggingObserver.emit = l.append
            obs.emit('foo')
            self.assertEqual(len(l), 1)
        finally:
            log.PythonLoggingObserver.emit = oldEmit

        Test that we can inherit L{log.PythonLoggingObserver} and use super:
        that's basically a validation that L{log.PythonLoggingObserver} is
        new-style class.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_log.py