Java Ellipse.centerXProperty()

public final DoubleProperty centerXProperty()

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Ellipse;
import javafx.stage.Stage;
//from  ww  w. j  ava  2s.c om
public class Main extends Application {
    public static void main(String[] args) {
        Application.launch(args);
    }
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Shapes");
        Group root = new Group();
        Scene scene = new Scene(root, 300, 300, Color.WHITE);

        Ellipse bigCircle = new Ellipse(20,20);
        bigCircle.setCenterX(20);
        bigCircle.setCenterY(20);
        bigCircle.setRadiusX(10);
        bigCircle.setRadiusY(10);
        
        System.out.println(bigCircle.centerXProperty().doubleValue());

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