code: def verify_grad(op, pt, n_tests=2, rng=None, *args, **kwargs):
      """
      Wrapper for gradient.py:verify_grad
      Takes care of seeding the random number generator if None is given
      """
      if rng is None:
          seed_rng()
          rng = np.random
      T.verify_grad(op, pt, n_tests, rng, *args, **kwargs)
  
imports: from __future__ import absolute_import, print_function, division
  from copy import copy, deepcopy
  from functools import wraps
  import logging
  import sys
  import unittest
  from parameterized import parameterized
  from nose.tools import assert_raises
  from six import integer_types
  from six.moves import StringIO
  import numpy
  import theano
  import theano.tensor
  from theano import config
label_desc: Use image node_id 4 for calling a global function with example usage: verify_grad(op, pt, n_tests, rng) without return types