public function getObjectCollection(\SimpleXMLElement $element)
 {
     $collection = new CategoryObjectCollection();
     if ($element->permissioncategories->category) {
         foreach ($element->permissioncategories->category as $node) {
             $category = new Category();
             $category->setHandle((string) $node['handle']);
             $category->setPackage((string) $node['package']);
             $collection->getCategories()->add($category);
             $category->setCollection($collection);
         }
     }
     return $collection;
 }