code: public void setLang(String lang)
      {
          AbstractHtmlState tsh = getState();
          tsh.registerAttribute(AbstractHtmlState.ATTR_GENERAL, LANG, lang);
      }
docs: Sets the lang attribute for the HTML element.
  @param lang
  @jsptagref.attributedescription Sets the language code for the base language of an
  element's attribute values and text content.
  @jsptagref.databindable false
  @jsptagref.attributesyntaxvalue <i>string_lang</i>
  @netui:attribute required="false" rtexprvalue="true"
  description="Sets the language code for the base language of an element's attribute values and text content."