public function getSitemapUrl()
    {
        $outputFilename = $this->getOutputFilename();
        if (strpos($outputFilename, DIR_BASE . '/') === 0) {
            $result = (string) $this->getSitemapGenerator()->resolveUrl([substr($outputFilename, strlen(DIR_BASE))]);
        } else {
            $result = '';
        }

        return $result;
    }