def test_normalExit(self):
        """
        _exitWithSignal is not called if the runner does not exit with a
        signal.
        """
        self.patch(
            twistd,
            '_SomeApplicationRunner',
            stubApplicationRunnerFactoryCreator(None)
        )
        twistd.runApp(self.config)
        self.assertIsNone(self.fakeKillArgs[0])
        self.assertIsNone(self.fakeKillArgs[1])

        _exitWithSignal is not called if the runner does not exit with a
        signal.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_twistd.py