def _update_key_value_metric(
        self, kv_inputs: Dict[str, torch.Tensor]
    ) -> Optional[Dict[str, float]]:
        """
        Update metric in key-value input case

        Args:
            kv_inputs: input tensors in key-value format

        Returns:
            result of metric update: None or metric values
        """
        return self._metric_update_method(**kv_inputs)

        Update metric in key-value input case

        Args:
            kv_inputs: input tensors in key-value format

        Returns:
            result of metric update: None or metric values
        
catalyst/callbacks/metric.py