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