code: def unpack_batch(batch, device):
      """Unpack a batch from the data loader."""
      inputs = [
          b.to(device) if b is not None else None for b in batch[:4]
      ]
      orig_idx = batch[4]
      return inputs, orig_idx
  
imports: import sys
  import numpy
  from collections import Counter
  import logging
  import torch
  from torch import nn
  import torch.nn.init
  import stanza.models.common.seq2seq_constant
  from stanza.models.common.trainer import Trainer
  from stanza.models.common.seq2seq_model import Seq2SeqModel
  from stanza.models.common import utils, loss
  from stanza.models.mwt.vocab import Vocab
label_desc: Use image node_id 1 for calling a global function with example usage: unpack_batch(batch, device) and returns: inputs,  orig_idx