code: @Override
      public ListSubscriptionsByTopicResult listSubscriptionsByTopic(ListSubscriptionsByTopicRequest request) {
          request = beforeClientExecution(request);
          return executeListSubscriptionsByTopic(request);
      }
docs: <p>
  Returns a list of the subscriptions to a specific topic. Each call returns a limited list of subscriptions, up to
  100. If there are more subscriptions, a <code>NextToken</code> is also returned. Use the <code>NextToken</code>
  parameter in a new <code>ListSubscriptionsByTopic</code> call to get further results.
  </p>
  <p>
  This action is throttled at 30 transactions per second (TPS).
  </p>
  
  @param listSubscriptionsByTopicRequest
  Input for ListSubscriptionsByTopic action.
  @return Result of the ListSubscriptionsByTopic operation returned by the service.
  @throws InvalidParameterException
  Indicates that a request parameter does not comply with the associated constraints.
  @throws InternalErrorException
  Indicates an internal service error.
  @throws NotFoundException
  Indicates that the requested resource does not exist.
  @throws AuthorizationErrorException
  Indicates that the user has been denied access to the requested resource.
  @sample AmazonSNS.ListSubscriptionsByTopic
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/sns-2010-03-31/ListSubscriptionsByTopic" target="_top">AWS
  API Documentation</a>