code: def test_failure_feature_vectors(self):
      x = np.random.rand(10, 3)
      preprocess = TotalVarMin()
  
      # Assert that value error is raised for feature vectors
      with self.assertRaises(ValueError) as context:
          preprocess(x)
  
      self.assertIn("Feature vectors detected.", str(context.exception))
  
file_path: adversarial-robustness-toolbox/tests/defences/test_variance_minimization.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import numpy
  from art.defences.preprocessor import TotalVarMin
  from tests.utils import master_seed
label_desc: Use image node_id 4 for calling the TestTotalVarMin obj's underlying member method code with example usage: obj.test_failure_feature_vectors() without return types