def serialize_amounts(data)
        data[:gross_amount] = BigDecimal(xml.css("grossAmount").text.to_f.to_s)
        data[:discount_amount] = BigDecimal(xml.css("discountAmount").text.to_f.to_s)
        data[:net_amount] = BigDecimal(xml.css("netAmount").text.to_f.to_s)
        data[:extra_amount] = BigDecimal(xml.css("extraAmount").text.to_f.to_s)