// POST api/marks
        public HttpResponseMessage Post(Mark value)
        {
            var created = this.markRepository.Add(value);

            var responce = Request.CreateResponse<Mark>(HttpStatusCode.Created, created);
            var resourceLink = Url.Link("DefaultApi", new { id = created.Id });

            responce.Headers.Location = new Uri(resourceLink);

            return responce;
        }
        // PUT api/marks/5
        public HttpResponseMessage Put(int id, Mark value)
        {
            if (id != value.Id || value == null)
            {
                return new HttpResponseMessage(HttpStatusCode.BadRequest);
            }

            var updated = this.markRepository.Update(id, value);

            var responce = Request.CreateResponse<Mark>(HttpStatusCode.Created, updated);
            var resourceLink = Url.Link("DefaultApi", new { id = updated.Id });

            responce.Headers.Location = new Uri(resourceLink);

            return responce;
        }