code: def test_grad_test_values(self):
      # Regression test for test values of `ifelse` gradient.
  
      backup = theano.config.compute_test_value
      theano.config.compute_test_value = "raise"
      try:
          x = tensor.scalar("x")
          x.tag.test_value = 1
          # Used to crash due to undefined test value.
          tensor.grad(ifelse(0, x, x), x)
      finally:
          theano.config.compute_test_value = backup
  
imports: from __future__ import absolute_import, print_function, division
  import unittest
  import numpy
  from nose.plugins.skip import SkipTest
  from six.moves import reduce
  import theano
  from theano import tensor
  import theano.ifelse
  from theano.ifelse import IfElse, ifelse
  from theano.tests import unittest_tools
label_desc: Use image node_id 22 for calling the test_ifelse obj's underlying member method code with example usage: obj.test_grad_test_values() without return types