code: def _lookup_tokens(
      self, tokens: List[Tuple[str, int, int]]
  ) -> List[int]:
      raise NotImplementedError
  
file_path: pytext/pytext/torchscript/tensorizer/bert.py
imports: from typing import List, Optional, Tuple
  import torch
  from pytext.torchscript.utils import pad_2d_mask
  from pytext.torchscript.vocab import ScriptVocabulary
  from pytorch.text.fb.utils.transform_utils import pad_2d
  from .tensorizer import ScriptTensorizer, VocabLookup
label_desc: Use image node_id 3 for calling the ScriptBERTTensorizerBase obj's underlying member method code with example usage: obj._lookup_tokens(tokens) without return types