catch (Exception e) { e.printStackTrace(); } return null;
  public URL getURL() {    if (cachedURLValid) {      return cachedURL;    } else {      try {        String url = elt.getStringAttribute("url");        if (url == null)          url = "";        cachedURLValid = true;        cachedURL = new URL(url);        return cachedURL;      }      catch (Exception e) {        e.printStackTrace();      }      cachedURLValid = true;      cachedURL = null;      return null;    }  }