def METHOD_NAME(batch):
    batch = transform(batch, batch_ops)
    # batch each field
    slots = []
    for items in batch:
        for i, item in enumerate(items):
            if len(slots) < len(items):
                slots.append([item])
            else:
                slots[i].append(item)
    return [np.stack(slot, axis=0) for slot in slots]