Java FlowLayout .preferredLayoutSize (Container target)

public Dimension preferredLayoutSize(Container target)

/*from w ww .j  av a  2s.c om*/
import java.awt.FlowLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel {
  public Main() {
    
    FlowLayout flowLayout = new FlowLayout(FlowLayout.RIGHT, 10, 3);
    setLayout(flowLayout);
    
    add(new JButton("w w w.j a v a 2 s . c o m"));
    add(new JButton("w w w.j a v a 2 s . com"));
    add(new JButton("w w w.java2s.com"));
    add(new JButton("www.j ava 2 s . c o m"));
    
    System.out.println(flowLayout.preferredLayoutSize(this));
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.add(new Main());

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}