code: @Override
      public ListSpeechSynthesisTasksResult listSpeechSynthesisTasks(ListSpeechSynthesisTasksRequest request) {
          request = beforeClientExecution(request);
          return executeListSpeechSynthesisTasks(request);
      }
docs: <p>
  Returns a list of SpeechSynthesisTask objects ordered by their creation date. This operation can filter the tasks
  by their status, for example, allowing users to list only tasks that are completed.
  </p>
  
  @param listSpeechSynthesisTasksRequest
  @return Result of the ListSpeechSynthesisTasks operation returned by the service.
  @throws InvalidNextTokenException
  The NextToken is invalid. Verify that it's spelled correctly, and then try again.
  @throws ServiceFailureException
  An unknown condition has caused a service failure.
  @sample AmazonPolly.ListSpeechSynthesisTasks
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/polly-2016-06-10/ListSpeechSynthesisTasks" target="_top">AWS
  API Documentation</a>