public static function mapExtensionToType($dataFile) {
        $ext = substr(strrchr($dataFile, '.'), 1);
        $ext = strtolower($ext);
        switch ($ext) {
            case 'xls':
            case 'xlsx':
                return 'Excel';
            break;
            case 'json':
                return 'Json';
            break;
            default:
                throw new Garp_Content_Import_Exception("Could not find importer for type $ext");
            break;
        }
    }