public virtual void ReturnMoney()
{
Money moneyToReturn = MoneyInside.AllocateCore(MoneyInTransaction);
MoneyInside -= moneyToReturn;
MoneyInTransaction = 0;
}
public virtual void BuySnack(int position)
{
if (CanBuySnack(position) != string.Empty)
{
throw new InvalidOperationException();
}
var slot = GetSlot(position);
slot.SnackPile = slot.SnackPile.SubstractOne();
var change = MoneyInside.AllocateCore(MoneyInTransaction - slot.SnackPile.Price);
MoneyInside -= change;
MoneyInTransaction = 0;
}