code: def test_grad(self):
      x = tf.constant([5, 4, 3, 2, 1], dtype=tf.float32)
      theoretical, numerical = tf.test.compute_gradient(
          zero_out_op_2.zero_out, tuple([x])
      )
      self.assertAllClose(theoretical, numerical)
  
file_path: tensorflow/tensorflow/examples/adding_an_op/zero_out_2_test.py
imports: import tensorflow
  from tensorflow.examples.adding_an_op import zero_out_grad_2
  from tensorflow.examples.adding_an_op import zero_out_op_2
label_desc: Use image node_id 3 for calling the ZeroOut2Test obj's underlying member method code with example usage: obj.test_grad() without return types