code: def test_Rop_dot_bug_18Oct2013_Jeremiah(self):
      # This test refers to a bug reported by Jeremiah Lowin on 18th Oct
      # 2013. The bug consists when through a dot operation there is only
      # one differentiable path (i.e. there is no gradient wrt to one of
      # the inputs).
      x = tensor.arange(20.0).reshape([1, 20])
      v = theano.shared(np.ones([20]))
      d = tensor.dot(x, v).sum()
      tensor.Rop(tensor.grad(d, v), v, v)
  
imports: from __future__ import absolute_import, print_function, division
  import unittest
  from theano.tests import unittest_tools
  from theano import function
  import theano
  from theano import tensor
  import itertools
  import numpy
  from theano.gof import Op, Apply
  from theano.gradient import grad_undefined
  from theano.tests.unittest_tools import SkipTest
  from theano.tensor.signal.pool import Pool
  from theano.tensor.nnet import conv, conv2d
label_desc: Use image node_id 26 for calling the test_RopLop obj's underlying member method code with example usage: obj.test_Rop_dot_bug_18Oct2013_Jeremiah() without return types