public static function addBackSlash($uri, $position = 'end')
    {
        switch ($position) {
            case 'top':
                $uri = '/' . ltrim($uri, '/');
                break;
            case 'end':
                $uri = rtrim($uri, '/') . '/';
                break;
            case 'both':
                $uri = ! empty($uri) ? '/' . trim($uri, '/') . '/' : '';
                break;
            default:
                $uri = false;
        }

        return $uri;
    }