py

import gc
import random
import functools
import contextlib


@functools.singledispatch
@contextlib.contextmanager
def make_context(obj):
    yield random.randint(1, 100)


def test_referrers():
    obj = object()
    assert len(gc.get_referrers(obj)) == 0
    with make_context(obj) as val:
        assert len(gc.get_referrers(obj)) == 0
        del obj
        assert isinstance(val, int)


__name__ == '__main__' and test_referrers()