Class OD

Lib/test/test_sys.py:1878–1879

        check(FS(), frozenset(), '3P')
        from collections import OrderedDict
        class OD(OrderedDict):
            __slots__ = 'a', 'b', 'c'
        check(OD(x=[]), OrderedDict(x=[]), '3P')

    def test_pythontypes(self):