text: public virtual DescribeEventCategoriesResponse DescribeEventCategories(DescribeEventCategoriesRequest request){var options = new InvokeOptions();options.RequestMarshaller = DescribeEventCategoriesRequestMarshaller.Instance;options.ResponseUnmarshaller = DescribeEventCategoriesResponseUnmarshaller.Instance;return Invoke<DescribeEventCategoriesResponse>(request, options);}