code: public function fromSubscriptions(string $topic): array
      {
          $response = [];
  
          if (empty($topic)) {
              return $response;
          }
  
          $subscriptions = $this->client->call('subscription', 'default', 'all', $topic);
          $subscriptions = json_decode($subscriptions, true) ?: [];
  
          foreach ($subscriptions as $subscription => $queues) {
              $topicPattern = str_replace(['.', '*', '#'], ['\.', '[a-zA-z0-9^.]{1,}', '.*'], $subscription);
              if (preg_match("/^$topicPattern$/", $topic)) {
                  $response = array_merge($response, $queues);
              }
          }
  
          return array_unique($response);
      }
docs: Gets a list of existent Queues matched by topic.
  
  @param  string $topic
  @return Queue[]