src/transformers/models/whisper/tokenization_whisper_fast.py/WhisperTokenizerFast/save_vocabulary
class WhisperTokenizerFast:    def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None) -> Tuple[str]:
        files = self._tokenizer.model.save(save_directory, name=filename_prefix)

        normalizer_file = os.path.join(
            save_directory, (filename_prefix + "-" if filename_prefix else "") + VOCAB_FILES_NAMES["normalizer_file"]
        )

        if self.english_spelling_normalizer is not None:
            with open(normalizer_file, "w", encoding="utf-8") as f:
                f.write(
                    json.dumps(self.english_spelling_normalizer, indent=2, sort_keys=True, ensure_ascii=False) + "\n"
                )

        return tuple(files) + (normalizer_file,)