protected function addItems($params, $options)
    {
        $items = [];

        if (isset($options['line_items']) && is_array($options['line_items'])) {
            foreach ($options['line_items'] as $item) {
                $items[] = [
                    'itemNumber'      => Arr::get($item, 'sku'),
                    'itemDescription' => Arr::get($item, 'description'),
                    'itemPrice'       => $this->gateway->amount(Arr::get($item, 'unit_price')),
                    'itemQuantity'    => (string) Arr::get($item, 'quantity', 1),
                    'itemBrandName'   => Arr::get($item, 'brand_name', ''),
                ];
            }
        }

        return $items;
    }