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 __init__(self, key):
        self.key = key
        self.prio = random.randint(0, 1000000000)
        self.size = 1
        self.left = None
        self.right = None