A good way to take locks in static methods involves adding a static internal synchronization object to the code 要较好地在静态方法中采用锁，需要向代码添加静态内部同步对象。
4.
You do not need to use the property if you have initialized the internal synchronization object in your class constructor 如果已在类构造函数中初始化内部同步对象，则无需使用该属性。
