如何在JavaFX中通过代码合并GridPane的单元格？

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

public class GridPaneMergeCellsExample extends Application {

    @Override
    public void start(Stage primaryStage) {
        GridPane gridPane = new GridPane();
        gridPane.setPadding(new Insets(10));
        gridPane.setHgap(10);
        gridPane.setVgap(10);

        // 创建组件
        Label label1 = new Label("Cell 1");
        Label label2 = new Label("Cell 2");
        Label label3 = new Label("Cell 3");
        Label label4 = new Label("Cell 4");

        // 设置合并单元格
        GridPane.setConstraints(label1, 0, 0, 2, 1); // 合并第一行的两个单元格
        GridPane.setConstraints(label2, 2, 0); // 第三列，第一行
        GridPane.setConstraints(label3, 0, 1); // 第一列，第二行
        GridPane.setConstraints(label4, 1, 1); // 第二列，第二行

        // 将组件添加到GridPane
        gridPane.getChildren().addAll(label1, label2, label3, label4);

        Scene scene = new Scene(gridPane, 300, 200);
        primaryStage.setScene(scene);
        primaryStage.setTitle("GridPane Merge Cells Example");
        primaryStage.show();
    }

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