```ruby
module KlarnaGateway
  module AmountCalculators::UK
    class LineItemCalculator
      def adjust_with(line_item)
        yield().merge({
          total_tax_amount: total_tax_amount(line_item),
          tax_rate: tax_rate(line_item),
          unit_price: unit_price(line_item),
          total_amount: total_amount(line_item),
          discount_amount: 0
        })
      end

      private

      def unit_price(line_item)
        line_item.display_price.cents
      end

      def total_amount(line_item)
        line_item.display_total.cents
      end

      def total_tax_amount(line_item)
        line_item.display_included_tax_total.cents
      end

      def tax_rate(line_item)
        if line_item.adjustments.tax.count == 1
          (line_item.adjustments.tax.first.source.amount * 10000).to_i
        else
          0
        end
      end
    end
  end
end
```

Use display_amount instead of display_total
user
```ruby
module KlarnaGateway
  module AmountCalculators::UK
    class LineItemCalculator
      def adjust_with(line_item)
        yield().merge({
          total_tax_amount: total_tax_amount(line_item),
          tax_rate: tax_rate(line_item),
          unit_price: unit_price(line_item),
          total_amount: total_amount(line_item),
          discount_amount: 0
        })
      end

      private

      def unit_price(line_item)
        line_item.display_price.cents
      end

      def total_amount(line_item)
        line_item.display_amount.cents
      end

      def total_tax_amount(line_item)
        line_item.display_included_tax_total.cents
      end

      def tax_rate(line_item)
        if line_item.adjustments.tax.count == 1
          (line_item.adjustments.tax.first.source.amount * 10000).to_i
        else
          0
        end
      end
    end
  end
end
```
assistant