def get_app_admin(self, app_id):
    """ Queries the AppController to see which user owns the given application.

    Args:
      app_id: The name of the app that we should see the administrator on.
    Returns:
      A str containing the name of the application's administrator, or None
        if there is none.
    Raises:
      AppScaleException if the AppController returns an error.
    """
    app_data_json = self.run_with_timeout(self.DEFAULT_TIMEOUT,
      'Get app admin request timed out.', self.DEFAULT_NUM_RETRIES,
      self.server.get_app_data, app_id, self.secret)
    if not app_data_json:
      return None

    try:
      app_data = json.loads(app_data_json)
    except ValueError as decode_error:
      if 'Error:' in app_data_json:
        raise AppScaleException(app_data_json)
      raise decode_error

    if app_data not in 'owner':
      return None

    return app_data['owner']
dataset/ETHPy150Open AppScale/appscale-tools/lib/appcontroller_client.py/AppControllerClient.get_app_admin/swapped operands of `not in`