Java TitledPane .collapsibleProperty ()

public final BooleanProperty collapsibleProperty()

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.control.TitledPane;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
// w w  w. j  av  a2  s. co m
public class Main extends Application {
    public static void main(String[] args) {
        launch(args);
    }
    @Override public void start(Stage stage) {
        stage.setTitle("TitledPane");
        Scene scene = new Scene(new Group(), 450, 250);
        scene.setFill(Color.GHOSTWHITE);

        Node rootIcon =  new ImageView(new Image(getClass().getResourceAsStream("root.png")));
        
        TitledPane gridTitlePane = new TitledPane("Title",rootIcon);
        
        
        GridPane grid = new GridPane();
        grid.setVgap(4);
        grid.setPadding(new Insets(5, 5, 5, 5));
        grid.add(new Label("To: "), 0, 0);
        grid.add(new TextField(), 1, 0);
        grid.add(new Label("Cc: "), 0, 1);
        grid.add(new TextField(), 1, 1);
        grid.add(new Label("Subject: "), 0, 2);
        grid.add(new TextField(), 1, 2);        
        grid.add(new Label("Attachment: "), 0, 3);
        grid.add(new Label("static value"),1, 3);
        gridTitlePane.setText("Grid");
        gridTitlePane.setContent(grid);
        
        System.out.println(gridTitlePane.collapsibleProperty());
        
        
        
        HBox hbox = new HBox(10);
        hbox.setPadding(new Insets(20, 0, 0, 20));
        hbox.getChildren().setAll(gridTitlePane);

        Group root = (Group)scene.getRoot();
        root.getChildren().add(hbox);
        stage.setScene(scene);
        stage.show();
    }
}
//