def test_createOrGetApplicationWithTapFile(self):
        """
        Ensure that the createOrGetApplication call that 'twistd -f foo.tap'
        makes will load the Application out of foo.tap.
        """
        config = twistd.ServerOptions()
        config.parseOptions(['-f', self.tapfile])
        application = CrippledApplicationRunner(
            config).createOrGetApplication()
        self.assertEqual(service.IService(application).name, 'Hi!')

        Ensure that the createOrGetApplication call that 'twistd -f foo.tap'
        makes will load the Application out of foo.tap.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_twistd.py