private void guiInit() {
    DefaultListModel listOfStuff = new DefaultListModel();
    partsList.setModel(listOfStuff);

    listOfStuff.addElement(new ElementOrNullWrapper(null, "Build Model from skeleton file"));

    Sandbox[] possibilities =
        (Sandbox[]) AuthoringTool.getInstance().getWorld().sandboxes.getArrayValue();

    for (int i = 0; i < possibilities.length; i++) {
      listOfStuff.addElement(new ElementOrNullWrapper(possibilities[i]));
    }
    partsList.setSelectedIndex(0);

    aliceFPSCombo.insertItemAt("15", 0);
    aliceFPSCombo.insertItemAt("30", 1);
    aliceFPSCombo.setSelectedIndex(1);

    nativeFPSCombo.insertItemAt("60", 0);
    nativeFPSCombo.insertItemAt("120", 1);
    nativeFPSCombo.setSelectedIndex(0);
  }