/**
* Add an object to the collection
*
* @param Varien_Object $object
* @return Mage_Eav_Model_Entity_Collection_Abstract
*/
public function addItem(Varien_Object $object)
{
if (get_class($object) !== $this->_itemObjectClass) {
throw Mage::exception('Mage_Eav', Mage::helper('eav')->__('Attempt to add an invalid object'));
}
return parent::addItem($object);
}
