public function existsMessage($language, $category, $message)
    {
        $key = $language . '/' . $category;
        if (!isset(static::$_messages[$key])) {
            static::$_messages[$key] = $this->loadMessages($category, $language);
        }
        if (isset(static::$_messages[$key][$message]) && static::$_messages[$key][$message] !== '') return true;
        else return false;
    }