code: func (c *EtcdGroupService) GroupRenewTTL(ctx context.Context, groupName string) error {
  	kv, err := getGroupKV(ctx, groupName)
  	if err != nil {
  		return err
  	}
  	if kv.Lease != 0 {
  		ctxT, cancel := context.WithTimeout(ctx, transactionTimeout)
  		defer cancel()
  		_, err = clientInstance.KeepAliveOnce(ctxT, clientv3.LeaseID(kv.Lease))
  		return err
  	}
  	return constants.ErrEtcdLeaseNotFound
  }
docs: // GroupRenewTTL will renew ETCD lease TTL