/**
  * Class constructor sets site manager instance and loads language file.
  *
  * @param vivvo_lite_site reference
  * @param string  (optional) Language name, default is "vietnamese"
  * @param string  (optional) Directory where language file lives
  * @return void
  *
  * TODO $site_manager needs to be removed in future releases
  */
 public function __construct($site_manager, $lang_name = '', $dir = '')
 {
     $this->load_lang($lang_name, $dir);
     self::$instance = $this;
 }