public async Task <GradeResponse.UpdateResponse> Update(GradeApiModel model)
        {
            var response = await PostEncodedContentWithSimpleResponse <GradeResponse.UpdateResponse, GradeApiModel>(updateUri, model);

            return(response);
        }
        public async Task <GradeResponse.AddResponse> AddNew(GradeApiModel model)
        {
            var response = await PostEncodedContentWithSimpleResponse <GradeResponse.AddResponse, GradeApiModel>(createUri, model);

            return(response);
        }