code: def test_works_correctly(self):
      f = lambda x: x**2 / 2
      g = lambda x: (x - 1) ** 3 / 3
      x = np.concatenate(
          [np.linspace(-100, 100, int(1e3)), [0.0]], axis=0
      )
      fx, gx = self.evaluate(
          gradient.value_and_gradient(
              lambda x_: custom_gradient.custom_gradient(
                  f(x_), g(x_), x_
              ),
              x,
          )
      )
      self.assertAllClose(f(x), fx)
      self.assertAllClose(g(x), gx)
  
file_path: probability/tensorflow_probability/python/math/custom_gradient_test.py
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import custom_gradient
  from tensorflow_probability.python.math import gradient
label_desc: Use image node_id 1 for calling the CustomGradientTest obj's underlying member method code with example usage: obj.test_works_correctly() without return types