code: def download_and_extract(data_dir):
      # download CIFAR-10 if not already downloaded.
      pass
  
file_path: dragonfly/examples/nas/cg/cifar/generate_cifar10_tfrecords.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import argparse
  import cPickle
  import os
  import tarfile
  from six.moves import xrange
  import tensorflow
label_desc: Use image node_id 1 for calling a global function with example usage: download_and_extract(data_dir) without return types