public void Update(int id, MovieViewModel movieVm)
        {
            var newActorsIds = movieVm.StarringActorsIds;
            var movie        = _repository.SearchForMovies(x => x.MovieId == id).First();

            movie.Update(movieVm);

            var currentActorMovies = _repository.SearchForMovies(x => x.MovieId == id).First().ActorsMovies.AsEnumerable();
            var newActorMovies     = newActorsIds.Select(x => new ActorMovie {
                ActorId = x, MovieId = id
            });

            _repository.Update(currentActorMovies, newActorMovies);
        }
        public void LinkActorToExistingMovie(int actorId, int movieId)
        {
            var currentActorMovies = _repository.SearchForMovies(x => x.MovieId == movieId).First().ActorsMovies.AsEnumerable();
            var currentActors      = currentActorMovies.Select(x => x.Actor);
            var currentActorsIds   = currentActors.Select(x => x.ActorId).ToList();

            var newActorsIds = currentActorsIds;

            newActorsIds.Add(actorId);

            var newActorMovies = newActorsIds.Select(x => new ActorMovie {
                ActorId = x, MovieId = movieId
            });

            _repository.Update(currentActorMovies, newActorMovies);
        }