public function getAmountCents()
    {
        if ($this->getNotForPayment()) {
            return 'XX';
        }
        $amount = $this->getAmount();
        $francs = intval($amount);
        $cents = round(($amount - $francs) * 100);
        return str_pad($cents, 2, '0', STR_PAD_LEFT);
    }