code: def test_get_feature_names_in(df_vartypes):
      tr = MockClass()
      tr._get_feature_names_in(df_vartypes)
      assert tr.n_features_in_ == df_vartypes.shape[1]
      assert tr.feature_names_in_ == list(df_vartypes.columns)
  
file_path: feature_engine/tests/test_selection/test_base_selector.py
imports: import pytest
  from pandas.testing import assert_frame_equal
  from feature_engine.selection.base_selector import BaseSelector
label_desc: Use image node_id 3 for calling a global function with example usage: test_get_feature_names_in(df_vartypes) without return types