@Override
  public void appendElementReference(@NotNull StringBuilder buf, RefElement refElement, String linkText, @NonNls String frameName) {
    final String url = ((RefElementImpl)refElement).getURL();
    if (url != null) {
      appendElementReference(buf, url, linkText, frameName);
    }
  }
@Override
  public void appendElementReference(@NotNull StringBuilder buf, RefElement refElement, String linkText, @NonNls String frameName)