@Override
  protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds) {
    if (alwaysShowTrack() || myMouseOverScrollbarExpandLevel > 0) {
      doPaintTrack(g, c, trackBounds);
    }
    RegionPainter<Object> painter = ClientProperty.get(c, JBScrollBar.TRACK);
    if (painter != null) {
      painter.paint((Graphics2D)g, trackBounds.x, trackBounds.y, trackBounds.width, trackBounds.height, null);
    }
  }
@Override
  protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds)