protected function addDiscountLines(array $params, array $options)
    {
        if (isset($options['discount'])) {
            $type = Arr::get($options, 'discount_type');
            if (!in_array($type, ['loyalty', 'campaign', 'coupon', 'sign'])) {
                $type = 'loyalty';
            }

            $code = Arr::get($options, 'discount_code', '---');
            if (strlen($code) < 3) {
                $code .= str_repeat('-', 3 - strlen($code));
            }

            $params['discount_lines'][] = [
                'type'   => $type,
                'code'   => $code,
                'amount' => $options['discount'],
            ];
        }

        return $params;
    }