partial void DeleteHangHoa(HangHoa instance);
 partial void UpdateHangHoa(HangHoa instance);
 private void detach_HangHoas(HangHoa entity)
 {
     this.SendPropertyChanging();
     entity.ChatLieu = null;
 }
 partial void InsertHangHoa(HangHoa instance);
 private void attach_HangHoas(HangHoa entity)
 {
     this.SendPropertyChanging();
     entity.ChatLieu = this;
 }