    def __init__(
        self, optimizer: Optimizer, step_size: int, gamma: float = 0.1, last_epoch: int = -1
    ) -> None:
        """

        Args:

        """

        lr_scheduler = torch.optim.lr_scheduler.StepLR(
            optimizer=optimizer, step_size=step_size, gamma=gamma, last_epoch=last_epoch
        )
        super().__init__(lr_scheduler)
Args:
allennlp/training/learning_rate_schedulers/pytorch_lr_schedulers.py