# File lib/nokogiri/xml/node.rb, line 690
      def write_xhtml_to io, options = {}
        # FIXME: this is a hack around broken libxml versions
        return (io << dump_html) if %w[2 6] === LIBXML_VERSION.split('.')[0..1]

        options[:save_with] ||= SaveOptions::FORMAT |
          SaveOptions::NO_DECLARATION |
          SaveOptions::NO_EMPTY_TAGS |
          SaveOptions::AS_XHTML
        write_to io, options
      end