Google\Cloud\PubSub\PubSubClient::subscriptions PHP Method

    public function subscriptions(array $options = [])
    {
        $options['pageToken'] = null;
        do {
            $response = $this->connection->listSubscriptions($options + ['project' => $this->formatName('project', $this->projectId)]);
            foreach ($response['subscriptions'] as $subscription) {
                (yield $this->subscriptionFactory($subscription['name'], $subscription['topic'], $subscription));
            }
            // If there's a page token, we'll request the next page.
            $options['pageToken'] = isset($response['nextPageToken']) ? $response['nextPageToken'] : null;
        } while ($options['pageToken']);
    }