go init
https://blog.csdn.net/upstream480/article/details/128994361
init 执行顺序
参考：
https://blog.csdn.net/upstream480/article/details/128994361
https://blog.csdn.net/upstream480/article/details/128994361
init 执行顺序
参考：
https://blog.csdn.net/upstream480/article/details/128994361