Class SimpleUserDict

Lib/test/mapping_tests.py:419–425

        self.assertEqual(d, {1:2, 2:4, 3:4, 5:6})

        class SimpleUserDict:
            def __init__(self):
                self.d = {1:1, 2:2, 3:3}
            def keys(self):
                return self.d.keys()
            def __getitem__(self, i):
                return self.d[i]
        d.clear()
        d.update(SimpleUserDict())
        self.assertEqual(d, {1:1, 2:2, 3:3})