code: func (qs *queryResponseStream) sendResponse(from string, payload []byte) error {
  	header := responseHeader{
  		Seq:   qs.seq,
  		Error: "",
  	}
  	rec := queryRecord{
  		Type:    queryRecordResponse,
  		From:    from,
  		Payload: payload,
  	}
  	return qs.client.Send(&header, &rec)
  }
docs: // sendResponse is used to send a single response