old_contents: # -*- coding:utf-8 -*-
  from jumeaux.models import FinalAddOnPayload
  
  
  class FinalExecutor:
      def exec(self, payload: FinalAddOnPayload):
          raise NotImplementedError()
  
new_contents: # -*- coding:utf-8 -*-
  from jumeaux.models import FinalAddOnPayload
  
  
  class FinalExecutor:
      def exec(self, payload: FinalAddOnPayload) -> FinalAddOnPayload:
          raise NotImplementedError()
  
subject: Add return type