code: @Override
  	public boolean releaseTaskManager(final ResourceID resourceId, final Exception cause) {
  
  		componentMainThreadExecutor.assertRunningInMainThread();
  
  		if (registeredTaskManagers.remove(resourceId)) {
  			releaseTaskManagerInternal(resourceId, cause);
  			return true;
  		} else {
  			return false;
  		}
  	}
docs: Unregister TaskManager from this pool, all the related slots will be released and tasks be canceled. Called
  when we find some TaskManager becomes "dead" or "abnormal", and we decide to not using slots from it anymore.
  
  @param resourceId The id of the TaskManager
  @param cause for the releasing of the TaskManager