Advantages to this approach include the fact that object authors can alter the copy without worrying about side - effects across other children of the parent 这样做的好处包括对象的作者可以修改这份副本而无须担心对此父类的其他子类产生副作用。
2.
Refers to enclosing object behavior and properties in a manner that makes them inaccessible to users unless the object author wants to allow that access 指的是以这样一种方式包含对象行为和特性：除非对象作者允许，否则用户无法访问该对象的行为和特性。
