code: @Override
      public DescribeDBClusterParameterGroupsResult describeDBClusterParameterGroups(DescribeDBClusterParameterGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeDBClusterParameterGroups(request);
      }
docs: <p>
  Returns a list of <code>DBClusterParameterGroup</code> descriptions. If a
  <code>DBClusterParameterGroupName</code> parameter is specified, the list will contain only the description of
  the specified DB cluster parameter group.
  </p>
  
  @param describeDBClusterParameterGroupsRequest
  @return Result of the DescribeDBClusterParameterGroups operation returned by the service.
  @throws DBParameterGroupNotFoundException
  <i>DBParameterGroupName</i> does not refer to an existing DB parameter group.
  @sample AmazonNeptune.DescribeDBClusterParameterGroups
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/neptune-2014-10-31/DescribeDBClusterParameterGroups"
  target="_top">AWS API Documentation</a>