code: def print_difference(mode, t1, t2):
      """Print the difference in timing between two runs."""
      difference = (t2 - t1) / t1 * 100.0
      print("=== %s: %.1f%% ===" % (mode, difference))
  
imports: import argparse
  import sys
  import time
  from tensorflow.python.client import session
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_nn_ops
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_impl
  from tensorflow.python.ops import random_ops
  from tensorflow.python.ops import variables
  import tensorflow.python.ops.nn_grad
  from tensorflow.python.platform import test
label_desc: Use image node_id 5 for calling a global function with example usage: print_difference(mode, t1, t2) without return types