private void SearchMoviesWithTags(List <string> tagKeys, SortDescriptor sort)
 {
     Movies.Clear();
     using (var repos = new RepositoryService())
     {
         var movies = repos.FindMoviesByTags(tagKeys, sort);
         foreach (var movie in movies)
         {
             Movies.Add(new MovieItemViewModel(movie.MovieId));
         }
     }
 }