private void addWindowMenuItem(final RegisterStage registerStage) { final MenuItem menuItem = new MenuItem(registerStage.accountProperty().get().getName()); menuItem.setUserData(registerStage); menuItem.setOnAction( event -> { final RegisterStage stage = (RegisterStage) menuItem.getUserData(); stage.requestFocus(); }); registerStage.setOnHiding(event -> windowMenu.getItems().removeAll(menuItem)); windowMenu.getItems().add(0, menuItem); }