argument(0)->value(); $backup = $image->getBackup($backupName); if (is_resource($backup) || $backup instanceof \GdImage) { // destroy current resource imagedestroy($image->getCore()); // clone backup $backup = $image->getDriver()->cloneCore($backup); // reset to new resource $image->setCore($backup); return true; } throw new RuntimeException( "Backup not available. Call backup() before reset()." ); } }