void paintBackground(Graphics g2, JComponent component) {
    Graphics2D g = (Graphics2D)g2;
    Dimension size = component.getSize();
    GraphicsConfig config = GraphicsUtil.setupAAPainting(g);
    RoundRectangle2D.Double rect = new RoundRectangle2D.Double(1.0, 1.0, size.width - 3, size.height - 3, 4.0, 4.0);

    if (UIUtil.isUnderDefaultMacTheme()) {
      g.setColor(Gray.xE0);
      g.fill(rect);
      g.setColor(Gray.xCA);
      g.draw(rect);
    } else {
      g.setColor(new JBColor(Gray.xE8, new Color(0x464a4d)));
      g.fill(rect);
      g.setColor(new JBColor(Gray.xCC, new Color(0x757b80)));
      g.draw(rect);
    }
    config.restore();
  }
void paintBackground(Graphics g2, JComponent component)