public Movie[] GetMoviesDirectedBy(string director)
        {
            IEnumerable <Movie> allMovies  = MovieProvider.GetAll();
            List <Movie>        resultList = new List <Movie>();

            foreach (var movie in allMovies)
            {
                if (IsDirectedBy(movie, director))
                {
                    resultList.Add(movie);
                }
            }

            return(resultList.ToArray());
        }