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

        prio_set_list.add(0, obj)
        assert obj in prio_set_list
def dfs(self,candidates,target,start,reslist):
        length = len(candidates)
        if target == 0: 
            return self.result.append(reslist)