src/FondOfSpryker/Zed/AvailabilityAlert/Business/Model/SubscriptionManager.php
public function isAlreadySubscribed(
        AvailabilityAlertSubscriptionTransfer $availabilityAlertSubscriptionTransfer
    ) {
        $availabilityAlertSubscriptionTransfer->requireEmail();
        $availabilityAlertSubscriptionTransfer->requireFkProductAbstract();

        $subscriptionCount = $this->queryContainer
            ->querySubscriptionByEmailAndIdProductAbstractAndStatus(
                $availabilityAlertSubscriptionTransfer->getEmail(),
                $availabilityAlertSubscriptionTransfer->getFkProductAbstract(),
                FosAvailabilityAlertSubscriptionTableMap::COL_STATUS_PENDING
            )->count();

        return $subscriptionCount === 1;
    }
public function isAlreadySubscribed(
        AvailabilityAlertSubscriptionTransfer $availabilityAlertSubscriptionTransfer
    ) {
        $availabilityAlertSubscriptionTransfer->requireEmail();
        $availabilityAlertSubscriptionTransfer->requireFkProductAbstract();

        $subscriptionCount = $this->queryContainer
            ->querySubscriptionByEmailAndIdProductAbstractAndStatus(
                $availabilityAlertSubscriptionTransfer->getEmail(),
                $availabilityAlertSubscriptionTransfer->getFkProductAbstract(),
                FosAvailabilityAlertSubscriptionTableMap::COL_STATUS_PENDING
            )->count();

        return $subscriptionCount === 1;
    }
@param \Generated\Shared\Transfer\AvailabilityAlertSubscriptionTransfer $availabilityAlertSubscriptionTransfer

@return bool