def test_loss_gradient(self):
        (_, _), (x_test, y_test) = self.mnist
        classifier = ClassifierWrapper(self.model_mnist)

        # Test gradient
        grads = classifier.loss_gradient(x_test, y_test)

        self.assertTrue(np.array(grads.shape == (NB_TEST, 28, 28, 1)).all())
        self.assertNotEqual(np.sum(grads), 0)
    def test_shapes(self):
        x_test, y_test = self.mnist[1]
        classifier = ClassifierWrapper(self.model_mnist)

        preds = classifier.predict(self.mnist[1][0])
        self.assertTrue(preds.shape == y_test.shape)

        self.assertTrue(classifier.nb_classes == 10)

        class_grads = classifier.class_gradient(x_test[:11])
        self.assertTrue(class_grads.shape == tuple([11, 10] + list(x_test[1].shape)))

        loss_grads = classifier.loss_gradient(x_test[:11], y_test[:11])
        self.assertTrue(loss_grads.shape == x_test[:11].shape)