public void AddInvoicesToCustomer(int customerId, int numOfInvoices, ISession session) { var rand = new Random(); var builder = new InvoiceBuilder(1, 1, 1).AddAmountProvider(() => rand.NextDouble() * 100); using (ITransaction transaction = session.BeginTransaction()) { for (int i = 0; i < numOfInvoices; i++) { var obj = builder.Construct(); session.SaveOrUpdate(obj); } transaction.Commit(); } }