How to set auto width for all column PHPSpreadSheet

<?php
require 'vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

$spreadsheet = new Spreadsheet();
$sheet = $spreadsheet->getActiveSheet();
$sheet->setCellValue('A1', 'Hello World !');
$sheet->setCellValue('B1', 'Auto Column !');
$for ($i = 'A'; $i !=  $spreadsheet->getActiveSheet()->getHighestColumn(); $i++) {
    $spreadsheet->getActiveSheet()->getColumnDimension($i)->setAutoSize(TRUE);
}
$writer = new Xlsx($spreadsheet);
$writer->save('hello world.xlsx');