private void detach_Orders(Order entity)
		{
			this.SendPropertyChanging();
			entity.Product = null;
		}
		private void detach_Orders(Order entity)
		{
			this.SendPropertyChanging();
			entity.Customer = null;
		}
		private void attach_Orders(Order entity)
		{
			this.SendPropertyChanging();
			entity.Product = this;
		}
		private void attach_Orders(Order entity)
		{
			this.SendPropertyChanging();
			entity.Customer = this;
		}