def test_all_classes_represented(self):
        """Ensure all classes are represented in the data."""
        (_, y_train), (_, y_test) = test_utils.get_test_data(
            self.train_samples,
            self.test_samples,
            self.input_shape,
            self.num_classes,
        )
        self.assertEqual(len(np.unique(y_train)), self.num_classes)
        self.assertEqual(len(np.unique(y_test)), self.num_classes)
Ensure all classes are represented in the data.
keras/src/testing/test_utils_test.py