code: def testNonDifferentiableDiscountedReturns(self):
      self.assertAllEqual(
          tf.gradients(
              self.op.extra.discounted_returns, self.invalid_grad_inputs
          ),
          self.invalid_grad_outputs,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  from six.moves import xrange
  import tensorflow.compat.v1
  import tree
  from trfl import discrete_policy_gradient_ops
label_desc: Use image node_id 3 for calling the SequenceAdvantageActorCriticLossGradientTest obj's underlying member method code with example usage: obj.testNonDifferentiableDiscountedReturns() without return types