import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.layout.HBox;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.KeyEvent;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

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

    @Override public void start(Stage stage) {
        stage.setTitle("Hello Button");
        //Group root = new Group();  // this still works
        HBox root = new HBox();  // this fails
        Scene scene = new Scene(root, 600, 450);
        scene.setFill(Color.PALEGREEN);
        Button button = new Button();
        button.setText("Button");
        root.getChildren().add(button);

        stage.setScene(scene);
        stage.show();
    }
}