code: public static JPanel makeButtonBox (Justification justification, Component... buttons)
      {
          JPanel box = new JPanel(new HGroupLayout(NONE, justification));
          for (Component button : buttons) {
              box.add(button);
              box.setOpaque(false);
          }
          return box;
      }
docs: Creates a {@link JPanel} that is configured with an {@link HGroupLayout} with a
  configuration conducive to containing a row of buttons. Any supplied buttons are added to
  the box.