class_docstr: Tests for policy_gradient op.
class_docstr_tok: ["Tests","for","policy_gradient","op","."]
code: def testGradients(self, multi_actions):
      self._setUp_loss(multi_actions)
      total_loss = tf.reduce_sum(self._loss)
      for policy_var in nest.flatten(self._policy_vars):
          gradients = tf.gradients(total_loss, policy_var)
          self.assertEqual(
              gradients[0].get_shape(), policy_var.get_shape()
          )
  
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 tensorflow_probability
  import tree
  from trfl import policy_gradient_ops
label_desc: Use image node_id 3 for calling the PolicyGradientLossTest obj's underlying member method code with example usage: obj.testGradients(multi_actions) without return types