private void detach_Films(Film entity)
 {
     this.SendPropertyChanging();
     entity.Category = null;
 }
 private void attach_Films(Film entity)
 {
     this.SendPropertyChanging();
     entity.Category = this;
 }
 partial void UpdateFilm(Film instance);
 partial void DeleteFilm(Film instance);
 partial void InsertFilm(Film instance);