protected function getModifiedTime(string $type): int
    {
        $files  = $this->getAssets($type);
        $latest = 0;

        foreach ($files as $file) {
            $mtime = (int) \filemtime($file);

            if ($mtime > $latest) {
                $latest = $mtime;
            }
        }

        return $latest;
    }