code: def df_clean(model, df):
      return model.clean_dataframe(
          df, ["abstract", "full_text"], new_col_name=CLEAN_COL
      )
  
file_path: recommenders/tests/unit/recommenders/models/test_tfidf_utils.py
imports: import pytest
  import scipy
  import pandas
  from recommenders.models.tfidf.tfidf_utils import TfidfRecommender
label_desc: Use image node_id 3 for calling a global function with example usage: df_clean(model, df) and returns: model