1.Future的異常拆解
https://blog.csdn.net/xxcupid/article/details/50492222
2.RemoveListener分析
https://blog.csdn.net/xxcupid/article/details/50492221
3.loadingCache的同步/異步load
https://blog.csdn.net/xxcupid/article/details/92834521
4.Caffeine Cache對Guava Cache做的優化
todo