    def aggregate_logging_outputs(
        logging_outputs: List[Dict[str, Any]]
    ) -> Dict[str, Any]:
        """Aggregate logging outputs from data parallel training."""
        utils.deprecation_warning(
            "The aggregate_logging_outputs API is deprecated. "
            "Please use the reduce_metrics API instead."
        )
        raise NotImplementedError
Aggregate logging outputs from data parallel training.
fairseq/criterions/fairseq_criterion.py