重学OC第二十四篇：启动优化

https://blog.csdn.net/nsf724947554/article/details/109998192

https://www.jianshu.com/p/52e0dee35830

https://www.cnblogs.com/zyzmlc/p/14080984.html

https://dishibolei.github.io/2017/08/17/ios-linkmap/