def _init_stub(self, service_name, *args, **kwargs):
    """Enable a stub by service name.

    Args:
      service_name: Name of service to initialize.  This name should be the
        name used by the service stub.

      Additional arguments are passed along to the specific stub initializer.

    Raises:
      NotActivatedError: When this function is called before testbed is
        activated or after it is deactivated.
      StubNotSupportedError: When an unsupported service_name is provided.
    """
    if not self._activated:
      raise NotActivatedError('The testbed is not activated.')
    method_name = INIT_STUB_METHOD_NAMES.get(service_name, None)
    if method_name is None:
      msg = service_name % 'The "%s" service is not supported by testbed'
      raise StubNotSupportedError(msg)

    method = getattr(self, method_name)
    method(*args, **kwargs)
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/testbed/__init__.py/Testbed._init_stub/swapped operands of `%`