@Override
    public double getMissingMoney(double priceInEuros) {
        if (priceInEuros < 0)
            throw new IllegalArgumentException("ERR00034452b");

        if (priceInEuros > totalAmountInEuros)
            return priceInEuros - totalAmountInEuros;
        else
            return 0;
    }