你真的知道UML图的作用吗？

https://zm10.sm-tc.cn/?src=l4uLj8XQ0J2TkJjRnIybkdGRmovQm5qaj5qRh4rQno2LlpyTmtCbmouelpOM0MnOzc7KzM4%3D&uid=e998054103eb5a578eec485437df4b61&hid=d6d6361a77557dda01b42347bea8cac4&pos=9&cid=9&time=1513482553419&from=click&restype=1&pagetype=0000000002000408&bu=web&query=uml+%E5%9B%BE%E4%BD%9C%E7%94%A8&mode=&v=1&uc_param_str=dnntnwvepffrgibijbprsvdsdichei