code: def get_audiff_gradient(f, be, tensors):
      """
      get autodiff gradient w.r.t the tensors
      """
      op_tree = f(be, *tensors)
      ad = Autodiff(op_tree, be)
      return ad
  
file_path: neon/tests/test_backend_autodiff.py
imports: from builtins import zip
  import itertools
  import numpy
  from neon import NervanaObject
  from neon.backends.autodiff import Autodiff
  from utils import call_func, gen_backend_tensors, tensors_allclose
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: get_audiff_gradient(f, be, tensors) and returns: ad