code: func (p *pullMediatorImpl) SendReq(dest string, items []string, nonce uint64) {
  	req := &proto.GossipMessage{
  		Channel: p.config.Channel,
  		Tag:     p.config.Tag,
  		Nonce:   0,
  		Content: &proto.GossipMessage_DataReq{
  			DataReq: &proto.DataRequest{
  				MsgType: p.config.MsgType,
  				Nonce:   nonce,
  				Digests: util.StringsToBytes(items),
  			},
  		},
  	}
  	if p.logger.IsEnabledFor(zapcore.DebugLevel) {
  		p.logger.Debug("Sending", req.GetDataReq().FormattedDigests(), "to", dest)
  	}
  	sMsg, err := req.NoopSign()
  	if err != nil {
  		p.logger.Warningf("Failed creating SignedGossipMessage: %+v", errors.WithStack(err))
  		return
  	}
  	p.Sndr.Send(sMsg, p.peersWithEndpoints(dest)...)
  }
docs: // SendReq sends an array of items to a certain remote PullEngine identified
  // by a string