protected function addProductInfo(array &$line)
    {
        $invoiceSettings = $this->config->getInvoiceSettings();
        $this->addTokenDefault($line, Tag::ItemNumber, $invoiceSettings['itemNumber']);
        $this->addTokenDefault($line, Tag::Product, $invoiceSettings['productName']);
        $this->addNature($line);
        if (!empty($invoiceSettings['costPrice'])) {
            $value = $this->getTokenizedValue($invoiceSettings['costPrice']);
            if (!Number::isZero($value)) {
                // If we have a cost price we add it, even if this is no margin
                // invoice.
                $line[Tag::CostPrice] = $value;
            }
        }
    }