code: def test_estimator_lists():
      """[Utils] testing: test dummy estimator and preprocessing formatting."""
      assert_correct_format(ESTIMATORS_PROBA, PREPROCESSING)
      assert_correct_format(ESTIMATORS, PREPROCESSING)
      assert_correct_format(ECM, None)
      assert_correct_format(ECM_PROBA, None)
  
      assert _assert_format(_format_instances(ESTIMATORS))
      assert _assert_format(_format_instances(ESTIMATORS_PROBA))
      assert _assert_format(ECM)
      assert _assert_format(ECM_PROBA)
      assert _assert_format(PREPROCESSING)
  
imports: import numpy
  import os
  from mlens.ensemble.base import Layer, Sequential
  from mlens.utils.dummy import OLS, LogisticRegression, Scale
  from mlens.testing.dummy import ESTIMATORS, PREPROCESSING, ESTIMATORS_PROBA, ECM, ECM_PROBA, InitMixin
  from mlens.testing.dummy import Data, EstimatorContainer
  from mlens.utils import assert_correct_format
  from mlens.utils.formatting import _assert_format, _format_instances
  from mlens.utils.exceptions import NotFittedError
  from mlens.externals.sklearn.base import BaseEstimator
label_desc: Use image node_id 14 for calling a global function with example usage: test_estimator_lists() without return types