The commonly used go language development kit
Some usual toolkit，include：
Just mediate implemention in memory(publish：Topic，subscribe：channel）
only duplicate of singleflight in groupcache
program init,start,safe exit
- consistent:
- hrw:provides an implementation of Highest Random Weight hashing, an alternative to consistent hashing which is both simple and fast
- counter:multithreading counter
- waitwraper:a wrapper for simplify calling for waitgroup