code: def test_preserve_names(self):
      binary_cat_example = pd.DataFrame(
          {
              "ignore": ["UP", "UP", "DOWN", "FLAT"],
              "feature": ["UP", "UP", "DOWN", "FLAT"],
              "target": [1, 1, 0, 0],
          },
          columns=["ignore", "feature", "target"],
      )
  
      for encoder_name in encoders.__all__:
          with self.subTest(encoder_name=encoder_name):
              encoder = getattr(encoders, encoder_name)(
                  cols=["feature"]
              )
              result = encoder.fit_transform(
                  binary_cat_example, binary_cat_example["target"]
              )
              columns = result.columns
  
              self.assertTrue(
                  "ignore" in columns,
                  "Column 'ignore' is missing in: " + str(columns),
              )
  
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 23 for calling the TestEncoders obj's underlying member method code with example usage: obj.test_preserve_names() without return types