private void attach_InvoiceLineItems(InvoiceLineItem entity)
		{
			this.SendPropertyChanging();
			entity.Invoice = this;
		}
 partial void DeleteInvoiceLineItem(InvoiceLineItem instance);
 partial void InsertInvoiceLineItem(InvoiceLineItem instance);
 partial void UpdateInvoiceLineItem(InvoiceLineItem instance);
		private void detach_InvoiceLineItems(InvoiceLineItem entity)
		{
			this.SendPropertyChanging();
			entity.Product = null;
		}