/**
  * Parse children.
  * @param DOMElement $parentNode
  */
 protected function parseChildren($parentNode)
 {
     foreach ($parentNode->childNodes as $childNode) {
         if ($childNode->nodeType == XML_ELEMENT_NODE && $childNode->nodeName == 'Properties') {
             $this->parseProperties($childNode);
         }
     }
     parent::parseChildren($parentNode);
 }