def METHOD_NAME(self) -> None:
    cache = self.with_cache("keeping_cache", ms=9001)
    expected_result = "howdy"
    wrap_d = defer.ensureDeferred(
        cache.wrap(0, self.instant_return, expected_result)
    )
    self.assertEqual(
        expected_result,
        self.successResultOf(wrap_d),
        "initial wrap result should be the same",
    )
    # a second call should return the result without a call to the wrapped function
    unexpected = Mock(spec=())
    wrap2_d = defer.ensureDeferred(cache.wrap(0, unexpected))
    unexpected.assert_not_called()
    self.assertEqual(
        expected_result,
        self.successResultOf(wrap2_d),
        "cache should still have the result",
    )