checkPromotion example

if (isset($cacheKey)) {
            $this->rateLimiter->reset(RateLimiter::GUEST_LOGIN, $cacheKey);
        }

        $response = new OrderRouteResponse($orderResult);
        if ($request->get('checkPromotion') === true) {
            foreach ($orders as $order) {
                $promotions = $this->getActivePromotions($order, $context);
                $changeable = true;
                foreach ($promotions as $promotion) {
                    $changeable = $this->checkPromotion($promotion);
                    if ($changeable === true) {
                        break;
                    }
                }
                $response->addPaymentChangeable([$order->getId() => $changeable]);
            }
        }

        return $response;
    }