code: def raise_301(instance, location):
      
      _set_location(instance, location)
      instance.response.status = 301
      raise ResponseException(instance.response)
docs: Abort the current request with a 301 (Moved Permanently) response code.
      Sets the Location header correctly. If the location does not start with a
      slash, the path of the current request is prepended.
  
      :param instance: Resource instance (used to access the response)
      :type instance: :class:`webob.resource.Resource`
      :raises: :class:`webob.exceptions.ResponseException` of status 301