public void EmptySetsQuantityToZero() { VendingMachineViewModel vendingMachineViewModel = new VendingMachineViewModel(); vendingMachineViewModel.Refill(); vendingMachineViewModel.Empty(); Assert.Multiple(() => { Assert.AreEqual(0, vendingMachineViewModel.Items[0].Quantity); Assert.AreEqual(0, vendingMachineViewModel.Items[1].Quantity); Assert.AreEqual(0, vendingMachineViewModel.Items[2].Quantity); Assert.AreEqual(0, vendingMachineViewModel.Items[3].Quantity); }); }