public static <T> Updatable addMoveDownListener(@NotNull JButton button, @NotNull JList<T> list) {
    button.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        moveSelectedItemsDown(list);
        list.requestFocusInWindow();
      }
    });
    return disableWhenNoSelection(button, list);
  }
public static <T> Updatable addMoveDownListener(@NotNull JButton button, @NotNull JList<T> list)