def test_bool(self):
        prio_set_list = event._PrioritizedSetList()

        assert bool(prio_set_list) is False

        prio_set_list.add(0, None)
        assert bool(prio_set_list) is True
def pop(self, key, default=None):
        value = self._collection.pop(key, default)
        if isinstance(value, Proxy):
            value = value.get()
        return value