private static function _unserializeRecursive(SimpleXMLElement $xml)
    {
        $result = [];
        $dataNamespace = Resources::DS_XML_NAMESPACE;
        /** @var SimpleXMLElement $child */
        foreach ($xml->children($dataNamespace) as $child) {
            if (count($child->children($dataNamespace)) > 0) {
                $value = [];
                $children = $child->children($dataNamespace);
                /** @var SimpleXMLElement $firstChild */
                $firstChild = $children[0];
                if ($firstChild->getName() == 'element') {
                    foreach ($children as $subChild) {
                        $value[] = self::_unserializeRecursive(
                            $subChild
                        );
                    }
                } else {
                    $value = self::_unserializeRecursive(
                        $child
                    );
                }
            } else {
                $value = (string) $child;
            }

            $result[$child->getName()] = $value;
        }

        return $result;
    }