def create(self, create_subscription_request: CreateSubscriptionRequest):
        subscription = Subscription()
        park, error = self.park_repo.get_by_id(
            create_subscription_request.park_id)
        if park is not None and error is None:
            subscription.park = park
        else:
            return None, error

        user, error = self.user_repo.get_by_id(
            create_subscription_request.user_id)
        if user is not None and error is None:
            subscription.user = user
        else:
            return None, error

        subscription = Subscription(created_at=time.time_ns(),
                                    park=park,
                                    user=user)
        subscription, error = self.subscription_repo.create(subscription)
        if subscription is not None and error is None:
            return self.subscription_schema.dump(subscription).data, None
        else:
            return None, error