code: def check_error_response(self, body, status):
      
      status_code = int(status.split(' ', 1)[0])
      if status_code >= 300:
        raise errors.BackendError(body, status)
docs: Raise an exception if the response from the backend was an error.
  
      Args:
        body: A string containing the backend response body.
        status: A string containing the backend response status.
  
      Raises:
        BackendError if the response is an error.