public function writer($tmpPath = '')
    {
        $tmpPath = $tmpPath ?: $this->config->get('general.timestampPath');
        if (!$tmpPath) {
            $tmpPath = sys_get_temp_dir() . DIRECTORY_SEPARATOR;
        }
        $timestamp = [
            'js' => $this->config->get('js.timestamp'),
            'css' => $this->config->get('css.timestamp'),
        ];
        $writer = new AssetWriter($timestamp, $tmpPath, $this->config->theme());
        $writer->configTimestamp($this->config->modifiedTime());
        $writer->filterRegistry($this->filterRegistry());
        return $writer;
    }