/** Creates the JFrame that will contain everything. */
 protected JFrame createFrame() {
   JFrame retFrame = new JFrame("TreeTable III -- " + path);
   Dimension dimension = new Dimension(600, 400);
   retFrame.setSize(600, 600);
   retFrame.setMinimumSize(dimension);
   retFrame.addWindowListener(
       new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
           frame.dispose();
           if (--ttCount == 0) {
             System.exit(0);
           }
         }
       });
   return retFrame;
 }