def _tokenizer(self) -> Optional[Tokenizer]:
        """
        Get a Huggingface tokenizer for solar models.
        """
        if SOLAR_TOKENIZERS.get(self.model) != self.tokenizer_name:
            warnings.warn(
                f"You are using a different tokenizer than the one specified in the model. This may cause issues with token counting. Please use {SOLAR_TOKENIZERS[self.model]} as the tokenizer name."
            )
        return Tokenizer.from_pretrained(self.tokenizer_name)

        Get a Huggingface tokenizer for solar models.
        
llama-index-integrations/llms/llama-index-llms-upstage/llama_index/llms/upstage/base.py