code: public static void switchFocus (Stage stage, Focusable widget) {
  		if (focusedWidget == widget) return;
  		if (focusedWidget != null) focusedWidget.focusLost();
  		focusedWidget = widget;
  		if (stage != null) stage.setKeyboardFocus(null);
  		focusedWidget.focusGained();
  	}
docs: Takes focus from current focused widget (if any), and sets focus to provided widget
  @param stage if passed stage is not null then stage keyboard focus will be set to null
  @param widget that will acquire focus