code: def test_pipeline_kernel_pdp_df(classifier_pipeline_kernel_explainer):
      assert isinstance(
          classifier_pipeline_kernel_explainer.pdp_df("age"),
          pd.DataFrame,
      )
      assert isinstance(
          classifier_pipeline_kernel_explainer.pdp_df("sex"),
          pd.DataFrame,
      )
      assert isinstance(
          classifier_pipeline_kernel_explainer.pdp_df("age", index=0),
          pd.DataFrame,
      )
      assert isinstance(
          classifier_pipeline_kernel_explainer.pdp_df("sex", index=0),
          pd.DataFrame,
      )
  
imports: import pytest
  import pandas
  import numpy
label_desc: Use image node_id 18 for calling a global function with example usage: test_pipeline_kernel_pdp_df(classifier_pipeline_kernel_explainer) without return types