# File lib/action_view/helpers/form_tag_helper.rb, line 407
      def field_set_tag(legend = nil, &block)
        content = capture(&block)
        concat(tag(:fieldset, {}, true), block.binding)
        concat(content_tag(:legend, legend), block.binding) unless legend.blank?
        concat(content, block.binding)
        concat("</fieldset>", block.binding)
      end