code: def test_make_sure_ml_base_classifier_follows_base_estimator(self):
      classifier = ProblemTransformationBase()
      self.assertIsInstance(classifier, BaseEstimator)
  
imports: import itertools
  import unittest
  import numpy
  import scipy.sparse
  from builtins import range
  from builtins import zip
  from sklearn.base import BaseEstimator
  from .test_utils import SPARSE_MATRIX_FORMATS
  from ..base import ProblemTransformationBase
label_desc: Use image node_id 9 for calling the ProblemTransformationBaseTest obj's underlying member method code with example usage: obj.test_make_sure_ml_base_classifier_follows_base_estimator() without return types