def stopping_metric(self, stopping_metric):
        assert_is_type(stopping_metric, None, Enum("auto", "deviance", "logloss", "mse", "rmse", "mae", "rmsle", "auc", "lift_top_group", "misclassification", "mean_per_class_error", "custom", "custom_increasing"))
        self._parms["stopping_metric"] = stopping_metric