Freedom is the recognition of necessity.

For every dollar you spend purchasing something substantial， expect to pay a dollar in repairs， maintenance， or disposal by the end of its life.

The Liskov Substitution Principle is a fundamental concept in object-oriented programming, stating that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program.

我不是一个喜欢对抗的人，但如果必须的话，我会为自己站出来。