public static function arrayToXLS(Array $data, String $file = 'excel.xls')
    {
        $file = Base::suffix($file, '.xls');

        header("Content-Disposition: attachment; filename=\"$file\"");
        header("Content-Type: application/vnd.ms-excel;");
        header("Pragma: no-cache");
        header("Expires: 0");

        $output = fopen("php://output", 'w');

        foreach( $data as $column )
        {
            fputcsv($output, $column, "\t");
        }

        fclose($output);
    }