code: @Override
      public ListStepsResult listSteps(ListStepsRequest request) {
          request = beforeClientExecution(request);
          return executeListSteps(request);
      }
docs: <p>
  Provides a list of steps for the cluster in reverse order unless you specify stepIds with the request.
  </p>
  
  @param listStepsRequest
  This input determines which steps to list.
  @return Result of the ListSteps operation returned by the service.
  @throws InternalServerException
  This exception occurs when there is an internal failure in the EMR service.
  @throws InvalidRequestException
  This exception occurs when there is something wrong with user input.
  @sample AmazonElasticMapReduce.ListSteps
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticmapreduce-2009-03-31/ListSteps" target="_top">AWS API
  Documentation</a>