问如何关闭组件is JavaFX

EN

public class JavaFX_uiTabPane extends Application {

  /**
   * @param args the command line arguments
   */
  public static void main(String[] args) {
      launch(args);
  }

  @Override
  public void start(Stage primaryStage) {
      primaryStage.setTitle("http://java-buddy.blogspot.com/");
      Group root = new Group();
      Scene scene = new Scene(root, 400, 300, Color.WHITE);

      TabPane tabPane = new TabPane();
      BorderPane mainPane = new BorderPane();

      //Create Tabs
      Tab tabA = new Tab();
      tabA.setText("Tab A");
      tabPane.getTabs().add(tabA);

      Tab tabB = new Tab();
      tabB.setText("Tab B");
      tabPane.getTabs().add(tabB);

      Tab tabC = new Tab();
      tabC.setText("Tab C");
      tabPane.getTabs().add(tabC);

      mainPane.setCenter(tabPane);

      mainPane.prefHeightProperty().bind(scene.heightProperty());
      mainPane.prefWidthProperty().bind(scene.widthProperty());

      root.getChildren().add(mainPane);
      primaryStage.setScene(scene);
      primaryStage.show();
  }
}