Method __eq__

Lib/test/test_deque.py:171–173

(self, other)

    def test_contains_count_index_stop_crashes(self):
        class A:
            def __eq__(self, other):
                d.clear()
                return NotImplemented
        d = deque([A(), A()])
        with self.assertRaises(RuntimeError):
            _ = 3 in d