delivery_job_filter

# File actionmailer/lib/action_mailer/test_helper.rb, line 155
      def delivery_job_filter(job)
        job_class = job.is_a?(Hash) ? job.fetch(:job) : job.class

        Base.descendants.map(&:delivery_job).include?(job_class) ||
          ActionMailer::Parameterized::DeliveryJob == job_class
      end