Java Swing GridBagLayout:可以创建具有不同列数的行吗？

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class GridBagLayoutExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("GridBagLayout Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());

        GridBagConstraints constraints = new GridBagConstraints();

        // 第一行，占据两列
        constraints.gridx = 0;
        constraints.gridy = 0;
        constraints.gridwidth = 2;
        panel.add(new JButton("Button 1"), constraints);

        // 第二行，占据一列
        constraints.gridx = 0;
        constraints.gridy = 1;
        constraints.gridwidth = 1;
        panel.add(new JButton("Button 2"), constraints);

        // 第二行，占据两列
        constraints.gridx = 1;
        constraints.gridy = 1;
        constraints.gridwidth = 2;
        panel.add(new JButton("Button 3"), constraints);

        frame.add(panel);
        frame.pack();
        frame.setVisible(true);
    }
}