public Movie Update(Movie updatedMovie)
 {
     var movie = GetById(updatedMovie.Id);
     _movies.Remove(movie);
     _movies.Add(updatedMovie);
     return updatedMovie;
 }
 public Movie Add(Movie newMovie)
 {
     newMovie.Id = GenerateId();
     _movies.Add(newMovie);
     return newMovie;
 }