/**
  *
  * @param array $items 
  */
 public function add($items)
 {
     $this->objects_imported = 0;
     $this->objects_skipped = 0;
     foreach ($items as $item) {
         $title = $item->title;
         $description = $item->description;
         if (empty($title) || empty($description)) {
             $this->objects_skipped++;
             continue;
         }
         $item->c_id = $this->course->c_id;
         $item->session_id = $this->course->session_id;
         $repo = Notebook::repository();
         $success = $repo->save($item);
         if ($success) {
             $this->objects_imported++;
         } else {
             $this->objects_skipped++;
         }
     }
 }