def test_inheritedClassesInequality(self):
        """
        An instance of a class which derives from a class which mixes in
        L{FancyEqMixin} should compare unequal to an instance of the base
        class if any of their attributes compare unequal.
        """
        self.assertFalse(Record(1, 2) != DerivedRecord(1, 2))
        self.assertTrue(Record(1, 2) != DerivedRecord(1, 3))
        self.assertTrue(Record(1, 2) != DerivedRecord(2, 2))
        self.assertTrue(Record(1, 2) != DerivedRecord(3, 4))

        An instance of a class which derives from a class which mixes in
        L{FancyEqMixin} should compare unequal to an instance of the base
        class if any of their attributes compare unequal.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_util.py