# File lib/nokogiri/xml/node_set.rb, line 170
      def remove_class name = nil
        each do |el|
          if name
            classes = el['class'].to_s.split(/\s+/)
            if classes.empty?
              el.delete 'class'
            else
              el['class'] = (classes - [name]).uniq.join " "
            end
          else
            el.delete "class"
          end
        end
        self
      end