text: public virtual ListGatewayGroupsResponse ListGatewayGroups(ListGatewayGroupsRequest request){var options = new InvokeOptions();options.RequestMarshaller = ListGatewayGroupsRequestMarshaller.Instance;options.ResponseUnmarshaller = ListGatewayGroupsResponseUnmarshaller.Instance;return Invoke<ListGatewayGroupsResponse>(request, options);}