def METHOD_NAME(self, data: ExchangeObject, extra: dict | None = None) -> None:
    """
    Train network and produce new network from train data.
    Args:
        data: ExchangeObject containing current network weights to base training on.
        extra: Dict with additional information that can be provided by the FL system.
    Returns:
        None
    """
    raise NotImplementedError(f"Subclass {self.__class__.__name__} must implement this method.")