static function fetchDeliveriesByContentobjectIdCount($object_id, $status = array())
 {
     $conds = array('contentobject_id' => $object_id);
     if (is_string($status)) {
         $status = array($status);
     }
     if (is_array($status)) {
         $status = array_intersect(jajNewsletterDelivery::states(), $status);
     }
     if (count($status)) {
         $conds['state'] = array($status);
     }
     $rows = eZPersistentObject::count(jajNewsletterDelivery::definition(), $conds);
     return $rows;
 }