@Override
  public void runtime(String portletName, String queryString, String defaultPreferences)
      throws Exception {

    RuntimeTag.doTag(portletName, queryString, defaultPreferences, null, _request, _response);
  }
  @Override
  public void runtime(String portletName, String queryString) throws Exception {

    RuntimeTag.doTag(portletName, queryString, null, _request, _response);
  }