code: public function processUpload_postProcessAction(&$filename, DataHandler $pObj)
      {
          $filename = static::$imageResizer->processFile(
              $filename,
              '', // Target file name
              '', // Target directory
              null,
              $GLOBALS['BE_USER'],
              [$this, 'notify']
          );
      }
docs: Post-processes a file upload.
  
  @param string $filename The uploaded file
  @param DataHandler $parentObject
  @return void