Class D

Lib/test/test_sys.py:1884–1885

            __slots__ = 'a', 'b', 'c'
        check(BA(), bytearray(), '3P')
        class D(dict):
            __slots__ = 'a', 'b', 'c'
        check(D(x=[]), {'x': []}, '3P')
        class L(list):
            __slots__ = 'a', 'b', 'c'