public function getAllSubscriptions()
    {
        $limit = RequestInterface::MAX_LIST_LIMIT;
        $offset = 0;
        $subscriptions = [[]];

        while (true) {
            $subscriptionBatch = $this->getSubscriptionsResponse($offset);
            $subscriptions[] = $subscriptionBatch;
            $offset += $limit;
            if (\count($subscriptionBatch) < $limit) {
                break;
            }
        }

        return \array_merge(...$subscriptions);
    }