It is the first token of the sequence when built with
                special tokens.
            mask_token (`str`, *optional*, defaults to `"<mask>"`):
                The token used for masking values. This is the token used when training this model with masked language
                modeling. This is the token which the model will try to predict.
            additional_special_tokens (`List[str]`, *optional*, defaults to `["<eop>", "<eod>"]`):
                Additional special tokens used by the tokenizer.

        Attributes:
            sp_model (`SentencePieceProcessor`):
                The *SentencePiece* processor that is used for every conversion (string, tokens and IDs).
        TF)