class_docstr: Tests for policy_gradient op.
class_docstr_tok: ["Tests","for","policy_gradient","op","."]
code: def testLoss(self, sequence_length, batch_size, action_dim):
      self._setUp_loss(sequence_length, batch_size, action_dim)
      expected_loss_shape = [sequence_length, batch_size]
      self.assertEqual(
          self._loss.get_shape().as_list(), expected_loss_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 2 for calling the PolicyGradientTest obj's underlying member method code with example usage: obj.testLoss(sequence_length, batch_size, action_dim) without return types