code: def is_gzipped(file_name):
      file_handle = open(file_name, "rb")
      magic_number = file_handle.read(2)
      file_handle.close()
      is_gzipped = magic_number == b"\x1f\x8b"
      return is_gzipped
  
imports: from __future__ import division
  from __future__ import print_function
  from __future__ import absolute_import
  import sys
  import os
  import os.path
  import numpy
  from collections import namedtuple
  from collections import OrderedDict
  import json
  import deeplift
  import tensorflow
label_desc: Use image node_id 13 for calling a global function with example usage: is_gzipped(file_name) and returns: is_gzipped