def test_contains(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()

        prio_set_list.add(0, obj)
        assert obj in prio_set_list
def _check_sigint_gate_is_correct(self):
        assert (
            self._threads_ignoring_sigint >= 0
        ), "This should never happen, someone must have modified the counter outside of SignalHandler."