def on_load_checkpoint(self, checkpoint: Dict[str, Any]) -> None:
    """Remove `_metadata` key from the checkpoint.
    See https://github.com/neuraloperator/neuraloperator/pull/493
    """
    state_dict = checkpoint["state_dict"]
    metadata = state_dict.pop('_metadata', None)

    if metadata is not None:
        saved_version = metadata.get('_version', None)
        if saved_version is None:
            warnings.warn(f"Saved instance of {self.__class__} has no stored version attribute.")
        if saved_version != self.net._version:
            warnings.warn(f"Attempting to load a {self.__class__} of version {saved_version},"
                          f"But current version of {self.__class__} is {saved_version}")