code: def __init__(
      self,
      token2id: Dict = None,
      add_unk: bool = True,
      unk_token: str = "<UNK>",
      mask_token: str = "<MASK>",
  ):
      super().__init__(
          token2id=token2id, add_unk=add_unk, unk_token=unk_token
      )
      self._mask_token = mask_token
      self.mask_index = self.add_token(self._mask_token)
  
imports: from typing import Dict
label_desc: Use image node_id 1 to create a new CBOWVocabulary object from inherited base classes: Vocabulary with example: obj = CBOWVocabulary(token2id, add_unk, unk_token, mask_token)