code: func (pc *PeerClient) Deliver() (pb.Deliver_DeliverClient, error) {
  	conn, err := pc.commonClient.NewConnection(pc.address, pc.sn)
  	if err != nil {
  		return nil, errors.WithMessage(err, fmt.Sprintf("deliver client failed to connect to %s", pc.address))
  	}
  	return pb.NewDeliverClient(conn).Deliver(context.TODO())
  }
docs: // Deliver returns a client for the Deliver service