code: def gradFunc(self, arg):
      # create an input variable corresponding the inputs of the forward prop function
      gradIn = C.input(shape=arg.shape, dynamic_axes=arg.dynamic_axes)
      # create an input variable for the gradient passed from the next stage
      gradRoot = C.input(shape=arg.shape, dynamic_axes=arg.dynamic_axes)
      # first step is to take absolute value of input arg
      signGrad = abs(gradIn)
      # then compare its magnitude to 1
      signGrad = less_equal(signGrad, 1)
      # finish by multiplying this result with the input gradient
      return element_times(gradRoot, signGrad), gradIn, gradRoot
  
imports: from cntk import *
  from cntk.ops.functions import UserFunction
  import numpy
  import cntk
label_desc: Use image node_id 3 for calling the Sign obj's underlying member method code with example usage: obj.gradFunc(arg) and returns: element_times,  gradIn,  gradRoot