respond

# File actionpack/lib/action_controller/mime_responds.rb, line 173
      def respond
        for priority in @mime_type_priority
          if priority == Mime::ALL
            @responses[@order.first].call
            return
          else
            if @responses[priority]
              @responses[priority].call
              return # mime type match found, be happy and return
            end
          end
        end

        if @order.include?(Mime::ALL)
          @responses[Mime::ALL].call
        else
          @controller.send :head, :not_acceptable
        end
      end