    def _convert_id_to_token(self, index):
        """Converts an index (integer) in a token (str) using the vocab."""
        return self.ids_to_tokens.get(index, self.unk_token)
Converts an index (integer) in a token (str) using the vocab.
videomamba/video_mm/models/backbones/bert/tokenization_bert2.py