def test_arguments(self):
        """
        L{task.react} passes the elements of the list it is passed as
        positional arguments to the function it is passed.
        """
        args = []
        def main(reactor, x, y, z):
            args.extend((x, y, z))
            return defer.succeed(None)
        r = _FakeReactor()
        exitError = self.assertRaises(
            SystemExit, task.react, main, [1, 2, 3], _reactor=r)
        self.assertEqual(0, exitError.code)
        self.assertEqual(args, [1, 2, 3])

        L{task.react} passes the elements of the list it is passed as
        positional arguments to the function it is passed.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_task.py