code: def test_StackingEstimator_2():
      """Assert that the StackingEstimator returns transformed X with a synthetic feature in regression."""
      reg = RandomForestRegressor(random_state=42)
      stack_reg = StackingEstimator(
          estimator=RandomForestRegressor(random_state=42)
      )
      # fit
      reg.fit(training_features_r, training_target_r)
      stack_reg.fit(training_features_r, training_target_r)
      # get transformd X
      X_reg_transformed = stack_reg.transform(training_features_r)
  
      assert np.allclose(
          reg.predict(training_features_r), X_reg_transformed[:, 0]
      )
  
file_path: tpot/tests/stacking_estimator_tests.py
imports: import platform
  import numpy
  from tpot.builtins import StackingEstimator
  from sklearn.linear_model import LogisticRegression, Lasso
  from sklearn.ensemble import RandomForestClassifier, RandomForestRegressor
  from sklearn.pipeline import make_pipeline
  from tpot_tests import training_features, training_target, training_features_r, training_target_r
  from sklearn.model_selection import cross_val_score
  import warnings
label_desc: Use image node_id 2 for calling a global function with example usage: test_StackingEstimator_2() without return types