The biggest risk is not taking any risk. In a world that's changing quickly, the only strategy that is guaranteed to fail is not taking risks.

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.

理论是灰色的，而生活之树常青。

希望是长着羽毛的东西，栖息在灵魂里。