def METHOD_NAME():
    @given(seq=from_type(_NestedSequence[int]))
    def test(seq):
        assert hasattr(seq, "__iter__")
        def flatten(lst):
            for el in lst:
                try:
                    yield from flatten(el)
                except TypeError:
                    yield el
        assert all(isinstance(i, int) for i in flatten(seq))
    test()