code: def lookup_word(
      self, idx: int, possible_unk_token: Optional[str] = None
  ):
      if idx < len(self.vocab) and idx != self.unk_idx:
          return self.vocab[idx]
      else:
          return (
              self.vocab[self.unk_idx]
              if possible_unk_token is None
              else possible_unk_token
          )
  
file_path: pytext/pytext/torchscript/vocab.py
imports: from typing import Dict, List, Optional
  import torch
  import torch.nn
  from pytext.common.constants import SpecialTokens
label_desc: Use image node_id 9 for calling the ScriptVocabulary obj's underlying member method code with example usage: obj.lookup_word(idx, possible_unk_token) and returns: self, unknown