docs: @Override
      public ImageWrapper render() throws SimpleImageException {
          if(imageWrapper == null) {
              imageWrapper = imageRender.render();
          }
          
          if(param == null) {
              return imageWrapper;
          }
          
          for (int i = 0; i < imageWrapper.getNumOfImages(); i++) {
              BufferedImage img = ImageDrawHelper.drawWatermark(imageWrapper.getAsBufferedImage(i), param);
              imageWrapper.setImage(i, img);
          }
  
          return imageWrapper;
      }