code: func (es *eventStream) sendQuery(q *serf.Query) error {
  	id := es.client.RegisterQuery(q)
  
  	header := responseHeader{
  		Seq:   es.seq,
  		Error: "",
  	}
  	rec := queryEventRecord{
  		Event:   q.EventType().String(),
  		ID:      id,
  		LTime:   q.LTime,
  		Name:    q.Name,
  		Payload: q.Payload,
  	}
  	return es.client.Send(&header, &rec)
  }
docs: // sendQuery is used to send a single query event