真正的竞争力不是价格，而是价值。

晏子春秋

When people are confronted with a problem, they often try to solve it by breaking it down into smaller parts. But sometimes, the solution lies in seeing the problem as a whole.

The Liskov Substitution Principle is a fundamental concept in object-oriented programming, ensuring that derived classes can be used in place of their base classes without altering the correctness of the program.