def test_invalidString(self):
        """
        L{amp.DateTime.fromString} raises L{ValueError} when passed a string
        which does not represent a timestamp in the proper format.
        """
        d = amp.DateTime()
        self.assertRaises(ValueError, d.fromString, 'abc')

        L{amp.DateTime.fromString} raises L{ValueError} when passed a string
        which does not represent a timestamp in the proper format.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_amp.py