code: def _unhash(self, feature_name: str) -> str:
      last_component_idx = feature_name.rfind("_")
      if not feature_name.startswith("f_"):
          return feature_name  # etalon feature
      elif last_component_idx == 1:
          return feature_name[2:]  # fully hashed name, cannot unhash
      else:
          return feature_name[2:last_component_idx]
  
imports: import hashlib
  import itertools
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import pandas
  from pandas._typing import DtypeObj
  from upgini.autofe.all_operands import find_op
  from upgini.autofe.operand import Operand, PandasOperand
label_desc: Use image node_id 3 for calling the Column obj's underlying member method code with example usage: obj._unhash(feature_name) and returns: feature_name, feature_name, feature_name