Java SE (Java Platform, Standard Edition)

Hello everyone.

It seems Label.setTextAlignment() does not work.
All label texts are set left side.

What's wrong with my code ?
//------------------------------------------------------------
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.scene.text.TextAlignment;
import javafx.stage.Stage;

public class Label03 extends Application {

public void start(Stage stage) throws Exception {
//
Label label_1 = new Label("");
label_1.setPrefSize( 320, 60 );
label_1.setText( "TextAlignment.CENTER" );
label_1.setTextAlignment(TextAlignment.CENTER);
//
Label label_2 = new Label("");
label_2.setPrefSize( 320, 60 );
label_2.setText( "TextAlignment.JUSTIFY" );
label_2.setTextAlignment(TextAlignment.JUSTIFY);
//
Label label_3 = new Label("");
label_3.setPrefSize( 320, 60 );
label_3.setText( "TextAlignment.LEFT" );
label_3.setTextAlignment(TextAlignment.LEFT);
//
Label label_4 = new Label("");
label_4.setPrefSize( 320, 60 );
label_4.setText( "TextAlignment.RIGHT" );
label_4.setTextAlignment(TextAlignment.RIGHT);
//
VBox root = new VBox();
root.getChildren().addAll(label_1, label_2, label_3, label_4);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.setTitle("Label03");
stage.show();
}

public static void main(String[] args) {
launch(args);
}
}
//------------------------------------------------