code: def test_fit_transform_Reg_feature_selector():
      """Test fit_transform method of Reg_feature_selector class."""
      feature_selector = Reg_feature_selector(threshold=0)
      df_train = pd.read_csv("data_for_tests/clean_train.csv")
      y_train = pd.read_csv(
          "data_for_tests/clean_target.csv", squeeze=True
      )
      df_transformed = feature_selector.fit_transform(df_train, y_train)
      assert (df_transformed.columns == df_train.columns).all()
  
file_path: MLBox/tests/test_regression_feature_selector.py
imports: import pytest
  import pandas
  from mlbox.model.regression.feature_selector import Reg_feature_selector
label_desc: Use image node_id 6 for calling a global function with example usage: test_fit_transform_Reg_feature_selector() without return types