    def step_batch(self, batch_num_total: int = None) -> None:
        """
        By default, a scheduler is assumed to only update every epoch, not every batch.
        So this does nothing unless it's overriden.
        """
        return
By default, a scheduler is assumed to only update every epoch, not every batch.
So this does nothing unless it's overriden.
allennlp/training/scheduler.py