code: private void init() {
          setTitle("Validation Framework Test");
          setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
  
          // Create content pane
          JPanel contentPane = new JPanel(new MigLayout("fill, wrap 1"));
          setContentPane(contentPane);
  
          // Tabbed pane
          JTabbedPane tabbedPane = new JTabbedPane();
          contentPane.add(tabbedPane, "grow");
  
          // Create tabs
          tabbedPane.add("Constant info", createTabConstantInfo());
          tabbedPane.add("Disabled", createTabDisabled());
          tabbedPane.add("Single validation", createTabSingleCompWithValidation());
          tabbedPane.add("Split pane", createTabSplitPane());
          tabbedPane.add("Scroll pane", createTabScrollPane());
          tabbedPane.add("Small panels", createTabSmallPanels());
  
          // Set size
          Dimension size = new Dimension(640, 480);
          setSize(size);
  
          // Set location
          Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
          setLocation((screenSize.width - size.width) / 2, (screenSize.height - size.height) / 3);
      }
docs: Initializes the frame by creating its contents.