code: func BroadcastSend(broadcast Broadcast, addr string, envelope *common.Envelope) error {
  	err := broadcast.Send(envelope)
  	broadcast.CloseSend()
  
  	if err != nil {
  		return errors.Wrapf(err, "failed to send transaction to orderer %s", addr)
  	}
  	return nil
  }
docs: // broadcastSend sends transaction envelope to orderer service