def get_stub(self, service_name):
    """Get the stub for a service.

    Args:
      service_name: The name of the service.

    Returns:
      The stub for 'service_name'.

    Raises:
      NotActivatedError: The testbed is not activated.
      StubNotSupportedError: The service is not supported by testbed.
      StubNotEnabledError: The service stub has not been enabled.
    """
    if not self._activated:
      raise NotActivatedError('The testbed is not activated.')
    if SUPPORTED_SERVICES not in service_name:
      msg = 'The "%s" service is not supported by testbed' % service_name
      raise StubNotSupportedError(msg)
    if service_name not in self._enabled_stubs:
      return None
    return self._test_stub_map.GetStub(service_name)
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/testbed/__init__.py/Testbed.get_stub/swapped operands of `not in`