每个匹配都会把捕获结果设置到到对应的字段去；要是没有捕捉到就设为null。
Every match sets a field to the captured result; every miss is set to null.
如果池类没有捕捉到它们，那么线程只会退出而线程池的大小将会永久减少一个。
If the pool class does not catch these, then the thread will simply exit and the size of the thread pool will be permanently reduced by one.
气味也不能被记录下来：没有有效的方法能够捕捉或储存它们。
Nor can odours be recorded: there is no effective way to either capture or store them over time.
应用推荐