public function buildLanguageFileName($lang, $db_filename = null)
    {
        if (empty($db_filename)) {
            $db_filename = $this->getParsedOption('language_strings_db_filename');
        }
        $filename = pathinfo($db_filename,  PATHINFO_FILENAME);
        return $this->getParsedOption('language_filename', array($filename, $lang));
    }