@Override
    public ListClustersResult listClusters() {
        return listClusters(new ListClustersRequest());
    }
<p>
Provides the status of all clusters visible to this Amazon Web Services account. Allows you to filter the list of
clusters based on certain criteria; for example, filtering by cluster creation date and time or by status. This
call returns a maximum of 50 clusters in unsorted order per call, but returns a marker to track the paging of the
cluster list across multiple ListClusters calls.
</p>

@param listClustersRequest
       This input determines how the ListClusters action filters the list of clusters that it returns.
@return Result of the ListClusters operation returned by the service.
@throws InternalServerException
        This exception occurs when there is an internal failure in the Amazon EMR service.
@throws InvalidRequestException
        This exception occurs when there is something wrong with user input.
@sample AmazonElasticMapReduce.ListClusters
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticmapreduce-2009-03-31/ListClusters" target="_top">AWS
     API Documentation</a>
aws-java-sdk-emr/src/main/java/com/amazonaws/services/elasticmapreduce/AmazonElasticMapReduceClient.java