def lr_step_begin_epoch(self, epoch):
        """Adjust the learning rate at the beginning of the epoch."""
        self.lr_scheduler.step_begin_epoch(epoch)
        # prefer updating the LR based on the number of steps
        return self.lr_step_update()
Adjust the learning rate at the beginning of the epoch.
structured_prompting/fairseq-version/fairseq/fairseq/trainer.py