/**
  * @param array $entityIds
  * @return Mage_Catalog_Model_Resource_Category_Collection
  */
 protected function _preparedCollection(array $entityIds = array())
 {
     if (empty(self::$_categoryCollection)) {
         self::$_categoryCollection = Mage::getSingleton("catalog/category")->getCollection()->addAttributeToSelect("name");
         if (!empty($entityIds)) {
             self::$_categoryCollection->addFieldToFilter("entity_id", $entityIds);
         }
         self::$_categoryCollection->addFieldToFilter("entity_id", array("nin" => $this->_getHelper()->getRootCategoryIds()));
     }
     return self::$_categoryCollection;
 }