    def aggregate_logging_outputs(self, logging_outputs, criterion):
        """[deprecated] Aggregate logging outputs from data parallel training."""
        utils.deprecation_warning(
            "The aggregate_logging_outputs API is deprecated. "
            "Please use the reduce_metrics API instead."
        )
        with metrics.aggregate() as agg:
            self.reduce_metrics(logging_outputs, criterion)
            return agg.get_smoothed_values()
[deprecated] Aggregate logging outputs from data parallel training.
fairseq/tasks/fairseq_task.py