// PUT api/Products/5
        public HttpResponseMessage Put([FromODataUri] int key, Product product)
        {
            if (!ModelState.IsValid)
            {
                return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
            }

            if (key != product.Id)
            {
                return Request.CreateResponse(HttpStatusCode.BadRequest);
            }

            data.Entry(product).State = EntityState.Modified;

            try
            {
                data.SaveChanges();
            }
            catch (DbUpdateConcurrencyException ex)
            {
                return Request.CreateErrorResponse(HttpStatusCode.NotFound, ex);
            }

            return Request.CreateResponse(HttpStatusCode.NoContent);
        }
        // POST api/Products
        public HttpResponseMessage Post(Product product)
        {
            if (ModelState.IsValid)
            {
                data.Products.Add(product);
                data.SaveChanges();

                HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, product);
                response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = product.Id }));
                return response;
            }
            else
            {
                return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
            }
        }