code: final PullResponse pull(
        ProjectSubscriptionName subscription, boolean returnImmediately, int maxMessages) {
  
      PullRequest request =
          PullRequest.newBuilder()
              .setSubscription(subscription == null ? null : subscription.toString())
              .setReturnImmediately(returnImmediately)
              .setMaxMessages(maxMessages)
              .build();
      return pull(request);
    }
docs: /* package-private