# File lib/nokogiri/xml/node_set.rb, line 113
      def xpath *paths
        ns = paths.last.is_a?(Hash) ? paths.pop :
          (document.root ? document.root.namespaces : {})

        sub_set = NodeSet.new(document)
        each do |node|
          sub_set += node.xpath(*(paths + [ns]))
        end
        document.decorate(sub_set)
        sub_set
      end