function fetch()
 {
     $tab_id = session_history_manager::datermine_tab_id();
     $history = session::get('session_history');
     if (!isset($history[$tab_id])) {
         $history[$tab_id] = array();
     }
     return array_reverse($history[$tab_id]);
 }
 function &get_dataset(&$counter, $params)
 {
     $items = session_history_manager::fetch();
     return new array_dataset($items);
 }
 function run(&$filter_chain, &$request, &$response)
 {
   session_history_manager :: save();
   $filter_chain->next();
 }