public void GetEmployeePayrollHistoryTotalNetpay_Should_GetTotal() { var service = new PayrollService(empStub, uowStub); var list = new List <PayrollHistory>(); for (int i = 0; i < 4; i++) { list.Add(new PayrollHistory() { GrossIncome = 25000M, NetIncome = 15000M }); } empStub.FindItem(Arg.Any <int>()).Returns(new Employee() { PayrollHistories = list }); decimal result = service.GetEmployeePayrollHistoryTotalNetpay(Arg.Any <int>()); Assert.AreEqual(60000M, result); }