def unicode_test(seg_instance, seg_str):
            seg_gen_str = str(seg_instance)

            self.assertEqual(len(seg_gen_str), 240)
            self.assertEqual(len(seg_str), 240)
            self.assertEqual(seg_gen_str, seg_str)
def _cost_gp(self,x):
        """
        Predicts the time cost of evaluating the function at x.
        """
        m, _, _, _ = self.cost_model.predict_withGradients(x)
        return np.exp(m)