# File lib/nokogiri/xml/node.rb, line 881
      def do_xinclude options = XML::ParseOptions::DEFAULT_XML, &block
        options = Nokogiri::XML::ParseOptions.new(options) if Fixnum === options

        # give options to user
        yield options if block_given?

        # call c extension
        process_xincludes(options.to_i)
      end