code: def _list_required_methods(estimator):
      """Return list of required method names (beyond BaseEstimator ones)."""
      # all BaseObject children must implement these
      MUST_HAVE_FOR_OBJECTS = ["set_params", "get_params"]
  
      # all BaseEstimator children must implement these
      MUST_HAVE_FOR_ESTIMATORS = [
          "fit",
          "check_is_fitted",
          "is_fitted",  # read-only property
      ]
      # prediction/forecasting base classes that must have predict
      BASE_CLASSES_THAT_MUST_HAVE_PREDICT = (
          BaseClusterer,
          BaseRegressor,
          BaseForecaster,
      )
      # transformation base classes that must have transform
      BASE_CLASSES_THAT_MUST_HAVE_TRANSFORM = (
          BaseTransformer,
          BasePairwiseTransformer,
          BasePairwiseTransformerPanel,
      )
  
      required_methods = []
  
      if isinstance(estimator, BaseObject):
          required_methods += MUST_HAVE_FOR_OBJECTS
  
      if isinstance(estimator, BaseEstimator):
          required_methods += MUST_HAVE_FOR_ESTIMATORS
  
      if isinstance(estimator, BASE_CLASSES_THAT_MUST_HAVE_PREDICT):
          required_methods += ["predict"]
  
      if isinstance(estimator, BASE_CLASSES_THAT_MUST_HAVE_TRANSFORM):
          required_methods += ["transform"]
  
      if isinstance(estimator, BaseAligner):
          required_methods += [
              "get_alignment",
              "get_alignment_loc",
              "get_aligned",
              "get_distance",
              "get_distance_matrix",
          ]
  
      return required_methods
  
imports: from inspect import isclass, signature
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from sklearn.utils.validation import check_random_state
  from sktime.alignment.base import BaseAligner
  from sktime.base import BaseEstimator, BaseObject
  from sktime.classification.base import BaseClassifier
  from sktime.classification.early_classification import BaseEarlyClassifier
  from sktime.clustering.base import BaseClusterer
  from sktime.datatypes._panel._check import is_nested_dataframe
  from sktime.dists_kernels import BasePairwiseTransformer, BasePairwiseTransformerPanel
  from sktime.forecasting.base import BaseForecaster
  from sktime.registry import scitype
  from sktime.regression.base import BaseRegressor
  from sktime.tests._config import VALID_ESTIMATOR_TYPES
  from sktime.transformations.base import BaseTransformer
label_desc: Use image node_id 2 for calling a global function with example usage: _list_required_methods(estimator) and returns: required_methods