code: def iter_estimators_which_can_be_tested():
      ignored = (
          River2SKLBase,
          SKL2RiverBase,
          anomaly.LocalOutlierFactor,  # needs warm-start to work correctly
          compose.FuncTransformer,
          compose.Grouper,
          compose.Pipeline,
          compose.Prefixer,
          compose.Renamer,
          compose.Suffixer,
          compose.TargetTransformRegressor,
          facto.FFMClassifier,
          facto.FFMRegressor,
          facto.FMClassifier,
          facto.FMRegressor,
          facto.FwFMClassifier,
          facto.FwFMRegressor,
          facto.HOFMClassifier,
          facto.HOFMRegressor,
          feature_extraction.Agg,
          feature_extraction.TargetAgg,
          feature_selection.PoissonInclusion,
          imblearn.RandomOverSampler,
          imblearn.RandomUnderSampler,
          imblearn.RandomSampler,
          model_selection.SuccessiveHalvingClassifier,
          neighbors.LazySearch,
          neural_net.MLPRegressor,
          preprocessing.PreviousImputer,
          preprocessing.OneHotEncoder,
          preprocessing.StatImputer,
          time_series.base.Forecaster,
      )
  
      if PYTORCH_INSTALLED:
          ignored = (*ignored, PyTorch2RiverBase)
  
      def can_be_tested(estimator):
          return not inspect.isabstract(estimator) and not issubclass(
              estimator, ignored
          )
  
      for estimator in filter(can_be_tested, iter_estimators()):
          for params in estimator._unit_test_params():
              yield estimator(**params)
  
file_path: river/river/test_estimators.py
imports: from __future__ import annotations
  import importlib
  import inspect
  import pytest
  from river import anomaly, base, checks, compat, compose, facto, feature_extraction, feature_selection, imblearn, linear_model, model_selection, multiclass, neighbors, neural_net, preprocessing, time_series
  from sklearn import linear_model
  from river.compat.river_to_sklearn import River2SKLBase
  from river.compat.sklearn_to_river import SKL2RiverBase
label_desc: Use image node_id 2 for calling a global function with example usage: iter_estimators_which_can_be_tested() and returns: unknown