public void Test_Charge_Customer_Count() { //arrange ICheckInFee stubCheckInFee = MockRepository.GenerateStub <ICheckInFee>(); Pub target = new Pub(stubCheckInFee); stubCheckInFee.Stub(x => x.GetFee(Arg <Customer> .Is.Anything)).Return(100); var customers = new List <Customer> { new Customer { IsMale = true }, new Customer { IsMale = false }, new Customer { IsMale = false }, }; decimal expected = 1; //act var actual = target.CheckInisFemale(customers); //assert Assert.AreEqual(expected, actual); }