code: def lookup_token(self, token: str):
      if self._add_unk:
          return self._token2id.get(token, self.unk_index)
      else:
          return self._token2id.get(token, None)
  
imports: from typing import Dict
label_desc: Use image node_id 6 for calling the Vocabulary obj's underlying member method code with example usage: obj.lookup_token(token) and returns: self, self