code: public void setFallbackController(GraphicsController fallbackController) {
  		boolean fallbackActive = (controller == this.fallbackController);
  		this.fallbackController = fallbackController;
  		if (controller == null || fallbackActive) {
  			setController(fallbackController);
  		}
  	}
docs: An optional fallbackController to return to, when no controller is explicitly set, or when null is set. If no
  current controller is active when this setter is called, it is applied immediately.
  
  @param fallbackController
  The new fall-back controller.