启示：这一举动被华尔街视为经典。它证明了：最伟大的领导力，不仅在于知道如何开始，更在于知道何时结束自己的“统治”，让更适合的人来接棒。
union object_info *cursor[num_classes] = {0};
，这一点在PDF资料中也有详细论述
for queue in self._watch_queues:
derivative of cat|dog and c is der(cat,c) | der(dog,c), which is at|∅ and simplifies to at