public function serialize(Urls $urls)
{
$doc_xml = new DOMDocument('1.0', 'UTF-8');
$urls_xml = $doc_xml->createElement('urls');
$doc_xml->appendChild($urls_xml);
foreach ($urls->getUrls() as $key => $url) {
$url_elem_xml = $doc_xml->createElement('url');
$url_value_xml = $doc_xml->createElement('value', $url['value']);
$url_directory_xml = $doc_xml->createElement('directory', $url['directory']);
$url_elem_xml->setAttribute('key', $key);
$url_elem_xml->appendChild($url_value_xml);
$url_elem_xml->appendChild($url_directory_xml);
$urls_xml->appendChild($url_elem_xml);
}
$doc_xml->preserveWhiteSpace = false;
$doc_xml->formatOutput = true;
return $doc_xml->saveXML();
}
