code: func NewInfoSyncer(id string, etcdCli *clientv3.Client) *InfoSyncer {
  	return &InfoSyncer{
  		etcdCli:        etcdCli,
  		info:           getServerInfo(id),
  		serverInfoPath: fmt.Sprintf("%s/%s", ServerInformationPath, id),
  	}
  }
docs: // NewInfoSyncer return new InfoSyncer. It is exported for testing.