partial void DeleteCTHD(CTHD instance);
 partial void UpdateCTHD(CTHD instance);
 private void detach_CTHDs(CTHD entity)
 {
     this.SendPropertyChanging();
     entity.Hang = null;
 }
 partial void InsertCTHD(CTHD instance);
 private void attach_CTHDs(CTHD entity)
 {
     this.SendPropertyChanging();
     entity.Hang = this;
 }