private function getPlannedArtifactIds(PFUser $user, Planning_Milestone $milestone)
 {
     $sub_milestone_ids = $this->getSubmilestoneIds($user, $milestone);
     if (!$sub_milestone_ids) {
         return array();
     }
     return $this->dao->getPlannedItemIds($sub_milestone_ids);
 }
 /** @return AgileDashboard_Milestone_Backlog_DescendantItemsCollection */
 public function getTopMilestoneUnplannedBacklogItemsWithLimitAndOffset(PFUser $user, $limit, $offset)
 {
     $result = $this->item_dao->getUnplannedTopBacklogArtifactsWithLimitAndOffset($this->descendant_tracker_ids, $limit, $offset);
     return $this->getItemsForUser($user, $result, $this->item_dao->foundRows());
 }