def METHOD_NAME(self, policy):
    """
    Invoke udf_get() with policy is string
    """
    with pytest.raises(e.ParamError) as err_info:
        self.as_connection.udf_get(self.loaded_udf_name, self.udf_language, policy)
        assert err_info.value.code == AerospikeStatus.AEROSPIKE_ERR_PARAM