code: def testInvalidGradients(self, gae_lambda):
      self._setUp_td_loss(gae_lambda=gae_lambda)
      ins = nest.flatten(
          [self._rewards, self._pcontinues, self._bootstrap_value]
      )
      outs = [None] * len(ins)
  
      self.assertAllEqual(tf.gradients(self._loss, ins), outs)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import tensorflow.compat.v1
  import tree
  from trfl import value_ops
label_desc: Use image node_id 4 for calling the TDLambdaTest obj's underlying member method code with example usage: obj.testInvalidGradients(gae_lambda) without return types