code: def convert(batch, device):
      center, contexts = batch
      center = device.send(center)
      contexts = device.send(contexts)
      return center, contexts
  
imports: import argparse
  import collections
  import os
  import six
  import warnings
  import numpy
  import chainer
  from chainer.backends import cuda
  import chainer.functions
  import chainer.initializers
  import chainer.links
  import chainer.optimizers
  from chainer import reporter
  from chainer import training
  from chainer.training import extensions
label_desc: Use image node_id 1 for calling a global function with example usage: convert(batch, device) and returns: center,  contexts