use_new_args?

# File actionmailer/lib/action_mailer/message_delivery.rb, line 168
      def use_new_args?(job)
        parameters = job.public_instance_method(:perform).parameters

        parameters.find do |key, name|
          return true if key == :keyreq && name == :args

          key == :keyrest and name != :**
        end
      end