docs: protected Node inlineThumbnail(Document doc, ParsedURL urldata, Node eold) {
      RenderableImage img = ThumbnailRegistryEntry.handleURL(urldata);
      if(img == null) {
        LoggingUtil.warning("Image not found in registry: " + urldata.toString());
        return null;
      }
      ByteArrayOutputStream os = new ByteArrayOutputStream();
      try {
        os.write(SVGSyntax.DATA_PROTOCOL_PNG_PREFIX.getBytes());
        Base64EncoderStream encoder = new Base64EncoderStream(os);
        ImageIO.write(img.createDefaultRendering(), "png", encoder);
        encoder.close();
      }
      catch(IOException e) {
        LoggingUtil.exception("Exception serializing image to png", e);
        return null;
      }
      Element i = (Element) super.cloneNode(doc, eold);
      i.setAttributeNS(SVGConstants.XLINK_NAMESPACE_URI, SVGConstants.XLINK_HREF_ATTRIBUTE, os.toString().replaceAll("\\s*[\\r\\n]+\\s*", ""));
      return i;
    }