def test_twistReactorHasNoExitSignalAttr(self):
        """
        _exitWithSignal is not called if the runner's reactor does not
        implement L{twisted.internet.interfaces._ISupportsExitSignalCapturing}
        """
        reactor = MemoryReactor()
        options = TwistOptions()
        options["reactor"] = reactor
        options["fileLogObserverFactory"] = jsonFileLogObserver
        Twist.run(options)
        self.assertFalse(self.exitWithSignalCalled)

        _exitWithSignal is not called if the runner's reactor does not
        implement L{twisted.internet.interfaces._ISupportsExitSignalCapturing}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/twist/test/test_twist.py