public function buildFileName(AssetTarget $target, $timestamp = true)
    {
        $file = $target->name();
        if ($target->isThemed() && $this->theme) {
            $file = $this->theme . '-' . $file;
        }
        if ($timestamp) {
            $time = $this->getTimestamp($target);
            $file = $this->_timestampFile($file, $time);
        }
        return $file;
    }