code: @Override
      public java.util.concurrent.Future<ListSubscriptionsByTopicResult> listSubscriptionsByTopicAsync(String topicArn) {
  
          return listSubscriptionsByTopicAsync(new ListSubscriptionsByTopicRequest().withTopicArn(topicArn));
      }
docs: Simplified method form for invoking the ListSubscriptionsByTopic operation.
  
  @see #listSubscriptionsByTopicAsync(ListSubscriptionsByTopicRequest)