Inheritance: INotifyPropertyChanging, INotifyPropertyChanged
 partial void DeleteBug(Bug instance);
 partial void UpdateBug(Bug instance);
		private void detach_Bugs(Bug entity)
		{
			this.SendPropertyChanging();
			entity.Severity = null;
		}
 partial void InsertBug(Bug instance);
		private void attach_Bugs(Bug entity)
		{
			this.SendPropertyChanging();
			entity.Severity = this;
		}