public IHttpActionResult Post(AlbumRequestModel model)
        {
            if (!this.ModelState.IsValid)
            {
                return this.BadRequest(this.ModelState);
            }

            var album = new Album
            {
                Title = model.Title,
                Year = model.Year,
                Producer = model.Producer
            };

            this.data.Albums.Add(album);
            this.data.Albums.SaveChanges();

            return this.Ok(album);
        }
        public IHttpActionResult Put(int id, AlbumRequestModel model)
        {
            if (!this.ModelState.IsValid)
            {
                return this.BadRequest(this.ModelState);
            }

            var album = this.data.Albums
                .All()
                .FirstOrDefault(a => a.Id == id);

            if (album == null)
            {
                return this.BadRequest("Album with id " + id + " does not exist!");
            }

            album.Title = model.Title;
            album.Year = model.Year;
            album.Producer = model.Producer;

            this.data.Albums.Update(album);
            this.data.Albums.SaveChanges();

            return this.Ok(model);
        }