# File lib/action_view/helpers/record_tag_helper.rb, line 50
      def content_tag_for(tag_name, record, *args, &block)
        prefix  = args.first.is_a?(Hash) ? nil : args.shift
        options = args.first.is_a?(Hash) ? args.shift : {}
        concat content_tag(tag_name, capture(&block), 
          options.merge({ :class => "#{dom_class(record)} #{options[:class]}".strip, :id => dom_id(record, prefix) })), 
          block.binding
      end