code: func (s *CatShardInfo) String() string {
  	if s == nil {
  		return ":::::::"
  	}
  	return fmt.Sprintf("%v:%v:%v:%v:%v:%v:%v:%v", s.IndexName, s.Shard, s.Primary,
  		s.State, s.Docs, s.Store, s.NodeIP, s.NodeName)
  }
docs: // Print shard info