class Storage(ABC):
在購買與領養之間──談香港動物福祉2016年5月24日
，这一点在同城约会中也有详细论述
Backpressure — the ability for a slow consumer to signal a fast producer to slow down — is a first-class concept in Web streams. In theory. In practice, the model has some serious flaws.
2. 分区：小于pivot的放左边，大于的放右边