code: def validate_explainer(rai_insights, X_train, X_test, classes):
      if rai_insights.model is None:
          return
      explanations = rai_insights.explainer.get()
      assert isinstance(explanations, list)
      assert len(explanations) == 1
      explanation = explanations[0]
      if (
          rai_insights._feature_metadata is not None
          and rai_insights._feature_metadata.dropped_features
          is not None
      ):
          num_cols = (
              len(X_train.columns)
              - 1
              - len(rai_insights._feature_metadata.dropped_features)
          )
      else:
          num_cols = len(X_train.columns) - 1
      if classes is not None:
          assert len(explanation.local_importance_values) == len(
              classes
          )
          assert len(explanation.local_importance_values[0]) == len(
              X_test
          )
          assert (
              len(explanation.local_importance_values[0][0]) == num_cols
          )
      else:
          assert len(explanation.local_importance_values) == len(X_test)
          assert len(explanation.local_importance_values[0]) == num_cols
  
      properties = rai_insights.explainer.list()
      assert (
          properties[ListProperties.MANAGER_TYPE]
          == ManagerNames.EXPLAINER
      )
      assert "id" in properties
      assert properties["method"] == LIGHTGBM_METHOD
      if classes is not None:
          assert properties["model_task"] == ModelTask.CLASSIFICATION
      else:
          assert properties["model_task"] == ModelTask.REGRESSION
      assert properties["model_type"] is None
      assert properties["is_raw"] is False
      assert properties["is_engineered"] is False
  
      # Check the internal state of explainer manager
      assert rai_insights.explainer._is_added
      assert rai_insights.explainer._is_run
  
imports: import pytest
  from raiutils.exceptions import UserConfigValidationException
  from raiutils.models import ModelTask
  from responsibleai._internal.constants import ListProperties, ManagerNames
label_desc: Use image node_id 2 for calling a global function with example usage: validate_explainer(rai_insights, X_train, X_test, classes) without return types