public function getBrokerClicks($brokerId, $nb = 'nb')
 {
     $key = Util_MemCacheKey::get_broker_clicks($brokerId, $nb);
     APF::get_instance()->benchmark_begin(__CLASS__ . " getBrokerClicks ");
     $memcache = APF_Cache_Factory::get_instance()->get_memcache();
     // $memcache->delete($key);
     $list = $memcache->get($key);
     if (!$list) {
         $time = Util_MemCacheTime::get_broker_clicks();
         $list = parent::getBrokerClicks($brokerId, $nb);
         $memcache->add($key, $list, 0, $time);
     }
     APF::get_instance()->benchmark_end(__CLASS__ . " getBrokerClicks ");
     return $list;
 }