private static @Nullable JScrollBar findScrollBar(JComponent c, @JdkConstants.AdjustableOrientation int orientation) {
    if (c == null) return null;
    if (c instanceof JScrollBar && ((JScrollBar)c).getOrientation() == orientation) {
      return (JScrollBar)c;
    }
    for (Component comp : c.getComponents()) {
      if (comp instanceof JComponent) {
        final JScrollBar scrollBar = findScrollBar((JComponent)comp, orientation);
        if (scrollBar != null) {
          return scrollBar;
        }
      }
    }
    return null;
  }
private static @Nullable JScrollBar findScrollBar(JComponent c, @JdkConstants.AdjustableOrientation int orientation)