Class Col

Lib/test/test_collections.py:1086–1092

        self.assertIsSubclass(Sequence, Collection)
        # Check direct subclassing
        class Col(Collection):
            def __iter__(self):
                return iter(list())
            def __len__(self):
                return 0
            def __contains__(self, item):
                return False
        class DerCol(Col): pass
        self.assertEqual(list(iter(Col())), [])
        self.assertNotIsSubclass(list, Col)