setting isfolder via API

<?php
$resource = $modx->getObject('modResource', 22);

$resource->set('isfolder', 1);
$resource->save();

return '<p>The resource is now a folder</p>';

<?php
$resource = $modx->getObject('modResource', 22);
 
if (! $resource) {
   return '<p>Could not find resource 22</p>';
}
$resource->set('isfolder', 1);
$resource->save();
 
return '<p>The resource is now a folder</p>';

$resources = $modx->getCollection('modResource');

foreach ($resources as $resource) {
 $value = $resource->get('isfolder');
 $resource->set('isfolder', $value);
 $resource->save();
}

return '<p>Resources Set</p>';