public async Task<HttpResponseMessage> Post(ChairModel entity)
        {
            entity.ID = Guid.NewGuid().ToString("N");

            try
            {
                var result = await Service.InsertAsync(Mapper.Map<IChair>(entity));

                if (result == 0)
                    return Request.CreateResponse(HttpStatusCode.BadRequest, "Add operation error.");

                return Request.CreateResponse(HttpStatusCode.OK, result);
            }
            catch (Exception e)
            {
                return Request.CreateResponse(HttpStatusCode.BadRequest, e.Message);
            }
        }
        public async Task<HttpResponseMessage> Put(string ID, ChairModel entity)
        {
            try
            {
                if (ID != entity.ID)
                {
                    return Request.CreateResponse(HttpStatusCode.BadRequest,
                        "IDs do not match.");
                }

                var result = await Service.UpdateAsync(Mapper.Map<IChair>(entity));
                if (result == 1)
                {
                    return Request.CreateResponse(HttpStatusCode.OK, entity);
                }
                else
                {
                    return Request.CreateResponse(HttpStatusCode.InternalServerError,
                        "PUT unsuccessful.");
                }
            }
            catch (Exception e)
            {
                return Request.CreateResponse(HttpStatusCode.BadRequest, e.ToString());
            }
        }