Have the computational hygiene, if you like, to only go through accessors, only go through methods that are actually provided to you as you do this.

请大家注意计算卫生，如果你喜欢这么说的话，只通过访问器访问数据,当你访问数据的时候,通过提供给你的方法来访问。

麻省理工公开课 - 计算机科学及编程导论课程节选