@Override
  protected JComponent createNorthPanel() {
    final JComponent panel = new JPanel(new GridBagLayout());
    GridBagConstraints gbConstraints = new GridBagConstraints();

    gbConstraints.insets = JBUI.insetsBottom(UIUtil.DEFAULT_VGAP);
    gbConstraints.fill = GridBagConstraints.BOTH;
    gbConstraints.weightx = 1;
    gbConstraints.weighty = 1;
    gbConstraints.anchor = GridBagConstraints.EAST;
    myCbExns = new JComboBox (myRoots);
    panel.add(myCbExns, gbConstraints);

    return panel;
  }
@Override
  protected JComponent createNorthPanel()