partial void Deletecost(cost instance);
 partial void Updatecost(cost instance);
		private void detach_costs(cost entity)
		{
			this.SendPropertyChanging();
			entity.subrubric = null;
		}
 partial void Insertcost(cost instance);
		private void attach_costs(cost entity)
		{
			this.SendPropertyChanging();
			entity.subrubric = this;
		}