src/transformers/trainer_pt_utils.py/IterableDatasetShard/__init__
class IterableDatasetShard:    def __init__(
        self,
        dataset: IterableDataset,
        batch_size: int = 1,
        drop_last: bool = False,
        num_processes: int = 1,
        process_index: int = 0,
        seed: int = 0,
    ):
        self.dataset = dataset
        self.batch_size = batch_size
        self.drop_last = drop_last
        self.num_processes = num_processes
        self.process_index = process_index
        self.seed = seed
        self.epoch = 0
        self.num_examples = 0