Class RevPlusIter

Lib/test/test_collections.py:1038–1039

        class RevNoIter:
            def __reversed__(self): return reversed([])
        class RevPlusIter(RevNoIter):
            def __iter__(self): return iter([])
        self.assertNotIsSubclass(RevNoIter, Reversible)
        self.assertNotIsInstance(RevNoIter(), Reversible)
        self.assertIsSubclass(RevPlusIter, Reversible)