code: @Override
      public DescribeEventTopicsResult describeEventTopics(DescribeEventTopicsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeEventTopics(request);
      }
docs: <p>
  Obtains information about which SNS topics receive status messages from the specified directory.
  </p>
  <p>
  If no input parameters are provided, such as DirectoryId or TopicName, this request describes all of the
  associations in the account.
  </p>
  
  @param describeEventTopicsRequest
  Describes event topics.
  @return Result of the DescribeEventTopics operation returned by the service.
  @throws EntityDoesNotExistException
  The specified entity could not be found.
  @throws InvalidParameterException
  One or more parameters are not valid.
  @throws ClientException
  A client exception has occurred.
  @throws ServiceException
  An exception has occurred in AWS Directory Service.
  @sample AWSDirectoryService.DescribeEventTopics
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ds-2015-04-16/DescribeEventTopics" target="_top">AWS API
  Documentation</a>