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 serialize(self, value, display=False):
        if value is not None and display:
            return "********"
        return super().serialize(value, display)