class_docstr: This class tests the BlackBox Neural Network classifier.
class_docstr_tok: ["This","class","tests","the","BlackBox","Neural","Network","classifier","."]
code: def test_fit(self):
      classifier = get_classifier_bb_nn()
      self.assertRaises(
          NotImplementedError,
          lambda: classifier.fit(
              self.x_train_mnist,
              self.y_train_mnist,
              batch_size=self.batch_size,
              nb_epochs=2,
          ),
      )
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import tempfile
  import unittest
  import numpy
  from art.defences.preprocessor import FeatureSqueezing, JpegCompression, SpatialSmoothing
  from tests.utils import TestBase, get_classifier_bb, get_classifier_bb_nn
label_desc: Use image node_id 2 for calling the TestBlackBoxClassifierNeuralNetwork obj's underlying member method code with example usage: obj.test_fit() without return types