def test_iter(self):
        prio_set_list = event._PrioritizedSetList()
        objs = [(i,) for i in range(5)]
        for i, obj in enumerate(objs):
            prio_set_list.add(-i, obj)

        for i, set_ in enumerate(prio_set_list):
            assert set_ == (-i, {objs[i]})
def getR(self):
        # x 分量與 y 分量
        x = self.p1.x - self.p2.x
        y = self.p1.y - self.p2.y
        return math.sqrt(x * x + y * y)