public HttpResponseMessage Post(HttpRequestMessage request, PriceHistoryViewModel priceHistoryVm)
 {
     return(CreateHttpResponse(request, () =>
     {
         HttpResponseMessage response = null;
         if (!ModelState.IsValid)
         {
             request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
         }
         else
         {
             PriceHistory newPriceHistory = new PriceHistory();
             newPriceHistory.UpdatePriceHistory(priceHistoryVm);
             var category = _priceHistoryService.Add(newPriceHistory);
             _priceHistoryService.SaveChanges();
             response = request.CreateResponse(HttpStatusCode.Created, category);
         }
         return response;
     }));
 }