code: public void deleteAlertFromQueueById(String alert_id) throws IOException {
          String url = "queues/" + name + "/alerts/" + alert_id;
          IronReader reader = client.delete(url);
          reader.close();
      }
docs: Delete alert from a queue by alert id. If there is no queue, an EmptyQueueException is thrown.
  @param alert_id The alert id.
  @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.