def test_messageAlreadySet(self):
        """
        The old-style C{"message"} key is not modified if it already exists.
        """
        event = self.forwardAndVerify(dict(message=("foo", "bar")))
        self.assertEqual(event["message"], ("foo", "bar"))

        The old-style C{"message"} key is not modified if it already exists.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/logger/test/test_legacy.py