text: public virtual DescribeParameterGroupsResponse DescribeParameterGroups(DescribeParameterGroupsRequest request){var options = new InvokeOptions();options.RequestMarshaller = DescribeParameterGroupsRequestMarshaller.Instance;options.ResponseUnmarshaller = DescribeParameterGroupsResponseUnmarshaller.Instance;return Invoke<DescribeParameterGroupsResponse>(request, options);}