code: @Override
      public DescribeDBClustersResult describeDBClusters(DescribeDBClustersRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeDBClusters(request);
      }
docs: <p>
  Returns information about provisioned DB clusters. This API supports pagination.
  </p>
  
  @param describeDBClustersRequest
  @return Result of the DescribeDBClusters operation returned by the service.
  @throws DBClusterNotFoundException
  <i>DBClusterIdentifier</i> does not refer to an existing DB cluster.
  @sample AmazonNeptune.DescribeDBClusters
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/neptune-2014-10-31/DescribeDBClusters" target="_top">AWS API
  Documentation</a>