Avoid repeating loading if running command `wechat material_list file 0 5`
Avoid repeating loading if running command `wechat material_list file 0 5`

http://stackoverflow.com/questions/1482605/what-is-the-correct-way-to-write-a-singleton-pattern-in-ruby

skinnyworm/wechat-rails,zfben/wechat,Eric-Guo/wechat,wolflee/wechat-rails,Eric-Guo/wechat,TangMonk/wechat,wolflee/wechat-rails