/**
  * Initialize the item.
  * Generate the sub items of this item.
  */
 public function init()
 {
     $collection = $this->get_collection();
     // bail if this direction is disabled
     if ($this->get_direction_disabled()) {
         return;
     }
     // create subitem and its collection and assign it
     $html = $this->get_direction_html();
     $page = $this->get_direction_page_number();
     $subitems_collection = Carbon_Pagination_Item_Page::generate_single_subitem_collection($collection, $html, $page);
     $this->set_subitems_collection($subitems_collection);
 }