public function actionGetOptimalPrice($from, $to, $dateStart, $dateEnd, $forceUpdate)
 {
     try {
         $price = MFlightSearch::getOptimalPrice($from, $to, $dateStart, $dateEnd, $forceUpdate);
         $this->send($price);
         die;
     } catch (Exception $e) {
         $this->sendError(500, $e->getMessage());
     }
 }