Method second

tensorflow/python/eager/backprop_test.py:495–497

(x)

      return x

    def second(x):
      grad = backprop.gradients_function(first, [0])(x)[0]
      return math_ops.reduce_sum(grad, constant_op.constant([0]))

    f = constant_op.constant([[0.1]])
    grad = backprop.gradients_function(second, [0])(f)[0]