code: def sanity_check(args):
      
      if not os.path.isfile(
          os.path.join(
              args['django_application_folder'],
              'models.py'
          )
      ):
          print("django_application_folder is not a Django application folder")
          sys.exit(1)
docs: Verify if the work folder is a django app.
      A valid django app always must have a models.py file
      :return: None