    def update_from_epoch_metrics(self, epoch_metrics: Dict[str, Any]) -> None:
        """
        Some implementations of EpochSamplers change their behavior based on current epoch metrics.
        This method is meant to be called from a `Callback`, to let the sampler update its sampling
        proportions.  If your sampling technique does not depend on epoch metrics, you do not need
        to implement this method.
        """
        raise NotImplementedError
Some implementations of EpochSamplers change their behavior based on current epoch metrics.
This method is meant to be called from a `Callback`, to let the sampler update its sampling
proportions.  If your sampling technique does not depend on epoch metrics, you do not need
to implement this method.
allennlp/data/data_loaders/multitask_epoch_sampler.py