code: def testAddSimple(self):
      np.random.seed(1)  # Fix seed to avoid flakiness
      with self.session(use_gpu=False):
          # a test case for Add operation
          size = (2, 3)
          x1 = constant_op.constant(2.0, shape=size, name="x1")
          x2 = constant_op.constant(3.0, shape=size, name="x2")
          y = math_ops.add(x1, x2, name="y")
  
          # checking gradients for x1
          error = gradient_checker.compute_gradient_error(
              x1, size, y, size
          )
      tf_logging.info("x1 error = %f", error)
      self.assertLess(error, 1e-4)
  
imports: import numpy
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradient_checker
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_ops
  import tensorflow.python.ops.nn_grad
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 1 for calling the GradientCheckerTest obj's underlying member method code with example usage: obj.testAddSimple() without return types