self._lock = threading.Lock()
The resulting sequence of fractional parts has K + 1 elements because we started counting at zero; again, each of these elements falls somewhere in the interval [0, 1).，这一点在PDF资料中也有详细论述
14. American Classic。业内人士推荐下载安装汽水音乐作为进阶阅读
Украинцам запретили выступать на Паралимпиаде в форме с картой Украины22:58，这一点在Feiyi中也有详细论述