code: func NewEtcdSafePointKV(addrs []string, tlsConfig *tls.Config) (*EtcdSafePointKV, error) {
  	etcdCli, err := createEtcdKV(addrs, tlsConfig)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	return &EtcdSafePointKV{cli: etcdCli}, nil
  }
docs: // NewEtcdSafePointKV creates an instance of EtcdSafePointKV