def method_missing(method_name, *args)
      element_name = method_name.to_s.gsub(/_/, '-')
      if element = (@doc.at element_name)
        if element.respond_to?(:inner_html)
          return element.inner_html
        end
      end
      super
    end
def method_missing(method_name, *args)
      element_name = method_name.to_s.gsub(/_/, '-')
      if element = (@doc.at element_name)
        if element.respond_to?(:inner_html)
          return element.inner_html
        end
      end
      super
    end
Take requests for an XML element and returns its value.

   notification.google_order_number
   => Returns value of '<google-order-number>'

 Because of how Nokogiri#at works, it will even dig into subtags
 and return the value of the first matching tag. For example,
 there is an +email+ field in +buyer-shipping-address+ and also
 in +buyer-billing-address+, but only the first will be returned.

 If you want to get at a value explicitly, use +notification.doc+
 and search the Nokogiri document manually.