def data_loader(rng: jax.random.PRNGKey, dataset: Dataset, batch_size: int, shuffle: bool = False, drop_last=True):
    """
    Returns batches of size `batch_size` from `dataset`. If `drop_last` is set to `False`, the final batch may be incomplete,
    and range in size from 1 to `batch_size`. Shuffle batches if `shuffle` is `True`.
    """
    if shuffle:
        batch_idx = jax.random.permutation(rng, len(dataset))
        batch_idx = np.asarray(batch_idx)
    else:
        batch_idx = np.arange(len(dataset))

    if drop_last:
        steps_per_epoch = len(dataset) // batch_size
        batch_idx = batch_idx[: steps_per_epoch * batch_size]  # Skip incomplete batch.
        batch_idx = batch_idx.reshape((steps_per_epoch, batch_size))
    else:
        steps_per_epoch = math.ceil(len(dataset) / batch_size)
        batch_idx = np.array_split(batch_idx, steps_per_epoch)

    for idx in batch_idx:
        batch = dataset[idx]
        batch = {k: np.array(v) for k, v in batch.items()}

        yield batch

    Returns batches of size `batch_size` from `dataset`. If `drop_last` is set to `False`, the final batch may be incomplete,
    and range in size from 1 to `batch_size`. Shuffle batches if `shuffle` is `True`.
    
dpkd/transformers/examples/flax/summarization/run_summarization_flax.py