code: def test_policy_and_value_forward_shape(self):
      mock_dist = mock.MagicMock()
      mock_dist.n_inputs = 4
      model = rl.PolicyAndValue(policy_distribution=mock_dist)
      x = np.ones((2, 3))
      _, _ = model.init(shapes.signature(x))
      ys = model(x)
      self.assertEqual([y.shape for y in ys], [(2, 4), (2, 1)])
  
file_path: trax/trax/models/rl_test.py
imports: from unittest import mock
  from absl.testing import absltest
  import numpy
  from trax import shapes
  from trax.models import rl
label_desc: Use image node_id 3 for calling the RLTest obj's underlying member method code with example usage: obj.test_policy_and_value_forward_shape() without return types