code: def _fid_to_feature_name(self, fid: int, dataframe: DataFrame):
      if fid is None:
          return None
      return dataframe.schema.columns[fid]
  
imports: import numpy
  import pandas
  from fate.arch import Context
  from fate.arch.dataframe import DataFrame
  from fate.ml.ensemble.learner.decision_tree.tree_core.splitter import SplitInfo
  from typing import List
  import logging
label_desc: Use image node_id 9 for calling the DecisionTree obj's underlying member method code with example usage: obj._fid_to_feature_name(fid, dataframe) and returns: dataframe, None