code: def _wrapped_include(arg):
      
      pattern_list, app_namespace, instance_namespace = arg
      return include((pattern_list, app_namespace), namespace=instance_namespace)
docs: Convert the old 3-tuple arg for include() into the new format.
  
      The argument "arg" should be a tuple with 3 elements:
      (pattern_list, app_namespace, instance_namespace)
  
      Prior to Django 2.0, django.urls.conf.include() accepts 3-tuple arg
      (urlconf, namespace, app_name), but it was droppped in Django 2.0.
      This function is used to convert the older 3-tuple used in horizon code
      into the new format where namespace needs to be passed as the second arg.
  
      For more details, see
      https://docs.djangoproject.com/en/2.0/releases/1.9/#passing-a-3-tuple-or-an-app-name-to-include