code: def test_default_configuration_sparse_no_encoding(self):
      transformations = []
  
      for i in range(2):
          transformation, original = _test_preprocessing(
              NoEncoding, make_sparse=True
          )
          self.assertEqual(transformation.shape, original.shape)
          self.assertTrue(
              (transformation.todense() == original.todense()).all()
          )
          transformations.append(transformation)
          if len(transformations) > 1:
              self.assertEqual(
                  (
                      transformations[-1] != transformations[-2]
                  ).count_nonzero(),
                  0,
              )
  
file_path: auto-sklearn/test/test_pipeline/components/data_preprocessing/test_one_hot_encoding.py
imports: import numpy
  from scipy import sparse
  from autosklearn.pipeline.components.data_preprocessing.categorical_encoding.no_encoding import NoEncoding
  from autosklearn.pipeline.components.data_preprocessing.categorical_encoding.one_hot_encoding import OneHotEncoder
  from autosklearn.pipeline.util import _test_preprocessing
  import unittest
label_desc: Use image node_id 6 for calling the OneHotEncoderTest obj's underlying member method code with example usage: obj.test_default_configuration_sparse_no_encoding() without return types