code: def test_layers(self):
      classifier = get_image_classifier_kr_tf()
      self.assertEqual(len(classifier.layer_names), 3)
  
      layer_names = classifier.layer_names
      for i, name in enumerate(layer_names):
          act_i = classifier.get_activations(
              self.x_test_mnist, i, batch_size=128
          )
          act_name = classifier.get_activations(
              self.x_test_mnist, name, batch_size=128
          )
          np.testing.assert_array_equal(act_name, act_i)
  
file_path: adversarial-robustness-toolbox/tests/estimators/classification/test_input_filter.py
imports: import logging
  import unittest
  import numpy
  from tests.utils import TestBase, master_seed, get_image_classifier_kr_tf
label_desc: Use image node_id 4 for calling the TestInputFilter obj's underlying member method code with example usage: obj.test_layers() without return types