code: def _apply_mask_to_df(self, new_y_mask, new_df):
      df_to_ret = self._df if new_df is None else new_df
      if new_y_mask is None:
          return df_to_ret
  
      return df_to_ret[new_y_mask].reset_index(drop=True)
  
file_path: scattertext/scattertext/DataFrameCorpus.py
imports: from scattertext.indexstore import IndexStore
  from scattertext.Corpus import Corpus
label_desc: Use image node_id 2 for calling the DataFrameCorpus obj's underlying member method code with example usage: obj._apply_mask_to_df(new_y_mask, new_df) and returns: df_to_ret, df_to_ret