code: public void linkCallbacks(Object... callbackHandlers) {
      if (callbackHandlers != null) {
        for (TaskHandler proxyTask : new ArrayList<TaskHandler>(proxyTasks)) {
          proxyTask.clearCallbacks();
          proxyTask.appendCallbacks(callbackHandlers);
        }
      }
    }
docs: Links the specified callback handlers to their respective tasks.
  
  @param callbackHandlers an array of callback handlers