public IHttpActionResult Create(AlbumOutputModel album)
        {
            if (!this.ModelState.IsValid)
            {
                return this.BadRequest(this.ModelState);
            }

            var albumToAdd = new Album
                                 {
                                     Length = album.Length,
                                     ReleaseDate = album.ReleaseDate,
                                     Title = album.Title,
                                     Producer = album.Producer
                                 };

            this.musicArtistsData.Albums.Add(albumToAdd);
            this.musicArtistsData.SaveChanges();

            return this.Ok(album);
        }
        public IHttpActionResult Update(AlbumOutputModel album)
        {
            if (!this.ModelState.IsValid)
            {
                return this.BadRequest(this.ModelState);
            }

            var albumToUpdate = this.musicArtistsData.Albums.FirstOrDefault(al => al.Id == album.Id);

            if (albumToUpdate == null)
            {
                return this.BadRequest(NoSuchAlbum);
            }

            albumToUpdate.Length = album.Length;
            albumToUpdate.ReleaseDate = album.ReleaseDate;
            albumToUpdate.Title = album.Title;
            albumToUpdate.Producer = album.Producer;

            this.musicArtistsData.Albums.Update(albumToUpdate);
            this.musicArtistsData.SaveChanges();

            return this.Ok();
        }