Structural-结构型(7+1)¶
备注
定义一组算法，将每个算法都封装起来，并且使它们之间可以互换。将多个对象组装成较大的结构，并同时保持结构的灵活和高效，从程序的结构上解决模块之间的耦合问题。These concern class and object composition. They use inheritance to compose interfaces and define ways to compose objects to obtain new functionality.