code: @Override
      public BufferedImage getBackground(int width, int height) {
          BufferedImage result = new BufferedImage(width, height,
                  BufferedImage.TYPE_INT_RGB);
          Graphics2D graphics = result.createGraphics();
  
          BasicStroke bs = new BasicStroke(2.0f, BasicStroke.CAP_BUTT,
                  BasicStroke.JOIN_MITER, 2.0f, new float[]{2.0f, 2.0f}, 0.0f);
          graphics.setStroke(bs);
          AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC_OVER,
                  0.75f);
          graphics.setComposite(ac);
  
          graphics.translate(width * -1.0, 0.0);
          double delta = 5.0;
          double xt;
          double ts = 0.0;
          for (xt = 0.0; xt < (2.0 * width); xt += delta) {
              Arc2D arc = new Arc2D.Double(0, 0, width, height, 0.0, 360.0,
                      Arc2D.OPEN);
              graphics.draw(arc);
              graphics.translate(delta, 0.0);
              ts += delta;
          }
          graphics.dispose();
          return result;
      }
docs: {@inheritDoc}