public void UniqueRandomPickerShouldBeAbleToPickFromList() { var list = mocks.DynamicMock <IList <MyClass> >(); var picker = new UniqueRandomPicker <MyClass>(constraint, uniqueRandomGenerator); using (mocks.Record()) { var capacity = 10; var randomIndex = 3; var end = 2; uniqueRandomGenerator.Expect(x => x.Reset()); list.Expect(x => x.Count).Return(capacity); constraint.Expect(x => x.GetEnd()).Return(end); uniqueRandomGenerator.Expect(x => x.Next(0, capacity)).Return(randomIndex).Repeat.Times(end); list.Expect(x => x[randomIndex]).Return(new MyClass()); } picker.From(list); }