code: public void killTasks(
        String trackerName, InetAddress addr, List<KillTaskAction> killActions) {
      for (KillTaskAction killAction : killActions) {
        String description = "KillTaskAction " + killAction.getTaskID();
        LOG.info("Queueing " + description + " to worker " +
          trackerName + "(" + addr.host + ":" + addr.port + ")");
        allWorkQueues.enqueueAction(
            new ActionToSend(trackerName, addr, killAction, description));
      }
    }
docs: Enqueue kill tasks actions.
  @param trackerName The name of the tracker to send the kill actions to.
  @param addr The address of the tracker to send the kill actions to.
  @param killActions The kill actions to send.