# File lib/action_view/helpers/capture_helper.rb, line 123
      def content_for(name, content = nil, &block)
        existing_content_for = instance_variable_get("@content_for_#{name}").to_s
        new_content_for      = existing_content_for + (block_given? ? capture(&block) : content)
        instance_variable_set("@content_for_#{name}", new_content_for)
      end