src/transformers/models/reformer/tokenization_reformer.py/ReformerTokenizer/__init__
class ReformerTokenizer:    def __init__(
        self,
        vocab_file,
        eos_token="</s>",
        unk_token="<unk>",
        additional_special_tokens=[],
        sp_model_kwargs: Optional[Dict[str, Any]] = None,
        **kwargs,
    ) -> None:
        self.sp_model_kwargs = {} if sp_model_kwargs is None else sp_model_kwargs

        super().__init__(
            eos_token=eos_token,
            unk_token=unk_token,
            additional_special_tokens=additional_special_tokens,
            sp_model_kwargs=self.sp_model_kwargs,
            **kwargs,
        )

        self.vocab_file = vocab_file
        self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs)
        self.sp_model.Load(vocab_file)