import javax.swing.*;

public class ExitableJFrame extends JFrame {
   public ExitableJFrame() {
   }
   public ExitableJFrame(String title) {
     super(title);
   }
   public ExitableJFrame(GraphicsConfiguration gc) {
     super(gc);
   }
   public ExitableJFrame(String title, 
     GraphicsConfiguration gc) super(title, gc);
   }
   protected void frameInit() {
     super.frameInit();
     setDefaultCloseOperation(EXIT_ON_CLOSE);
   }
}