Abrir multiplas telas no JavaFX

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private void init(Stage primaryStage) {

        Group root = new Group();

        primaryStage.setScene(new Scene(root));

        //create a button for initializing our new stage

        Button button = new Button("Create a Stage");

        button.setStyle("-fx-font-size: 24;");

        button.setDefaultButton(true);

        button.setOnAction(new EventHandler<ActionEvent>() {

            @Override public void handle(ActionEvent t) {

                final Stage stage = new Stage();

                //create root node of scene, i.e. group

                Group rootGroup = new Group();

                //create scene with set width, height and color

                Scene scene = new Scene(rootGroup, 200, 200, Color.WHITESMOKE);

                //set scene to stage

                stage.setScene(scene);

                //center stage on screen

                stage.centerOnScreen();

                //show the stage

                stage.show();

                //add some node to scene

                Text text = new Text(20, 110, "JavaFX");

                text.setFill(Color.DODGERBLUE);

                text.setEffect(new Lighting());

                text.setFont(Font.font(Font.getDefault().getFamily(), 50));

                //add text to the main root group

                rootGroup.getChildren().add(text);

            }

        });

        root.getChildren().add(button);

    }

    @Override public void start(Stage primaryStage) throws Exception {

        init(primaryStage);

        primaryStage.show();

    }

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