code: def test_8_keras_mnist(self):
      classifier = get_image_classifier_kr()
  
      scores = classifier._model.evaluate(
          self.x_train_mnist, self.y_train_mnist
      )
      logging.info(
          "[Keras, MNIST] Accuracy on training set: %.2f%%",
          (scores[1] * 100),
      )
      scores = classifier._model.evaluate(
          self.x_test_mnist, self.y_test_mnist
      )
      logging.info(
          "[Keras, MNIST] Accuracy on test set: %.2f%%",
          (scores[1] * 100),
      )
  
      self._test_backend_mnist(
          classifier, self.x_test_mnist, self.y_test_mnist
      )
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import numpy
  from art.attacks.evasion.virtual_adversarial import VirtualAdversarialMethod
  from art.estimators.classification.keras import KerasClassifier
  from art.estimators.estimator import BaseEstimator
  from art.estimators.classification.classifier import ClassifierMixin
  from art.utils import get_labels_np_array
  from tests.utils import TestBase
  from tests.utils import get_image_classifier_tf, get_image_classifier_kr, get_image_classifier_pt
  from tests.utils import get_tabular_classifier_tf, get_tabular_classifier_kr, get_tabular_classifier_pt
  from tests.attacks.utils import backend_test_classifier_type_check_fail
label_desc: Use image node_id 2 for calling the TestVirtualAdversarial obj's underlying member method code with example usage: obj.test_8_keras_mnist() without return types