code: def test_ignored_columns_are_untouched(self):
      # Make sure None values in ignored columns are preserved.
      # See: https://github.com/scikit-learn-contrib/category_encoders/pull/261
      X = pd.DataFrame(
          {"col1": ["A", "B", None], "col2": ["C", "D", None]}
      )
      y = [1, 0, 1]
  
      for encoder_name in set(encoders.__all__):
          with self.subTest(encoder_name=encoder_name):
              enc = getattr(encoders, encoder_name)(cols=["col1"])
              out = enc.fit_transform(X, y)
              self.assertTrue(out.col2[2] is None)
  
imports: import warnings
  from datetime import timedelta
  import numpy
  from numpy.testing import assert_array_equal
  import pandas
  import sklearn
  import tests.helpers
  from sklearn.utils.estimator_checks import check_transformer_general, check_transformers_unfitted, check_n_features_in
  from sklearn.compose import ColumnTransformer
  from unittest import TestCase
  from copy import deepcopy
  import category_encoders
label_desc: Use image node_id 44 for calling the TestEncoders obj's underlying member method code with example usage: obj.test_ignored_columns_are_untouched() without return types