Как обновить все превью с водяными знаками?

<?php
define('MODX_API_MODE', true);
require 'index.php';

$modx->getService('error','error.modError');
$modx->setLogLevel(modX::LOG_LEVEL_ERROR);
$modx->setLogTarget(XPDO_CLI_MODE ? 'ECHO' : 'HTML');

$modx->addPackage('ms2gallery', MODX_CORE_PATH . 'components/ms2gallery/model/');
$files = $modx->getIterator('msResourceFile', array('parent' => 0));
foreach ($files as $file) {
    $children = $file->getMany('Children');
    foreach ($children as $child) {
        $child->remove();
    }
    $file->generateThumbnails();
}

echo microtime(true) - $modx->startTime;