private IList<Movie> FilterByActor(IList<Actor> Actors)
        {
            //from moviesToFilter from context
            return Actors == null ?
                moviesToFilter.Where(movie =>
                Actors.All(requiredActor =>
                movie.MovieActor.Any(movieActor =>
                movieActor.Actor == requiredActor))).ToList() : null;
        }