examples/research_projects/robust-speech-event/run_speech_recognition_ctc_streaming.py/ShuffleCallback/on_epoch_begin
class ShuffleCallback:        def on_epoch_begin(self, args, state, control, train_dataloader, **kwargs):
            if isinstance(train_dataloader.dataset, IterableDatasetShard):
                pass  # set_epoch() is handled by the Trainer
            elif isinstance(train_dataloader.dataset, IterableDataset):
                train_dataloader.dataset.set_epoch(train_dataloader.dataset._epoch + 1)