old_contents: from __future__ import absolute_import
  from django.conf import settings
  
  if settings.USE_CELERY:
      # This will make sure the app is always imported when
      # Django starts so that shared_task will use this app.
      from .celery import app as celery_app
new_contents: from __future__ import absolute_import
  
  try:
      from .celery import app as celery_app
  except ImportError:
      pass
subject: Implement celery