code: public void deleteAlertsFromQueue(ArrayList<Alert> alert_ids) throws IOException {
          String url = "queues/" + name + "/alerts";
          Alerts alert = new Alerts(alert_ids);
          String jsonMessages = gson.toJson(alert);
          IronReader reader = client.delete(url, jsonMessages);
          reader.close();
      }
docs: Delete alerts from a queue. If there is no queue, an EmptyQueueException is thrown.
  @param alert_ids The array list of alert ids.
  @throws io.iron.ironmq.HTTPException If the IronMQ service returns a status other than 200 OK.
  @throws java.io.IOException If there is an error accessing the IronMQ server.