def allow_job(job_class, params = nil)
      JobProductStruct.new(job_class, params).tap do |struct|
        _conflow_spec_test_instance._conflow_spec_returns << struct
      end
    end
def allow_job(job_class, params = nil)
      JobProductStruct.new(job_class, params).tap do |struct|
        _conflow_spec_test_instance._conflow_spec_returns << struct
      end
    end
Allows to define returned value by a job (which then can be user by hook attached to the job itself).
 @param job_class [Class] Class of the job
 @param params [Object] Value to be returned by job when processed
 @example
   class MyFlow < Conflow::Flow
     def configure(id:)
       run UpdateJob, params: { id: id }, hook: :send_notifications
     end

     def send_notifications(emails:)
       emails.each { |email| run NotificationJob, params: { email: email } }
     end
   end

   RSpec.describe MyFlow do
     before { allow_job(UpdateJob, id: 110).to produce(emails: ["user1@example.com", "user2@example.com"]) }
     subject { described_class.create(id: 110) }

     it { is_expected.to run_job(NotificationJob).with_params(email: "user1@example.com") }
     it { is_expected.to run_job(NotificationJob).with_params(email: "user2@example.com") }
   end