    def to_str(self) -> str:
        """
        Returns:
          Return a string representation of this object. You can pass
          it to the method ``from_str`` to recreate an identical object.
        """
        s = ""
        for idx, symbol in sorted(self._id2sym.items()):
            s += f"{symbol} {idx}\n"
        return s
Returns:
Return a string representation of this object. You can pass
it to the method ``from_str`` to recreate an identical object.
models/tts/debatts/utils/symbol_table.py