code: def testSharedLayer(self):
      shared_layer = tf.keras.layers.Dense(
          1,
          kernel_initializer=tf.constant_initializer([0]),
          bias_initializer=tf.constant_initializer([0]),
          name="shared",
      )
  
      critic_net_1 = DummyCriticNet(shared_layer=shared_layer)
      critic_net_2 = DummyCriticNet(shared_layer=shared_layer)
  
      target_shared_layer = tf.keras.layers.Dense(
          1,
          kernel_initializer=tf.constant_initializer([0]),
          bias_initializer=tf.constant_initializer([0]),
          name="shared_target",
      )
  
      target_critic_net_1 = DummyCriticNet(
          shared_layer=target_shared_layer
      )
      target_critic_net_2 = DummyCriticNet(
          shared_layer=target_shared_layer
      )
  
      agent = sac_agent.SacAgent(
          self._time_step_spec,
          self._action_spec,
          critic_network=critic_net_1,
          critic_network_2=critic_net_2,
          target_critic_network=target_critic_net_1,
          target_critic_network_2=target_critic_net_2,
          actor_network=None,
          actor_optimizer=None,
          critic_optimizer=None,
          alpha_optimizer=None,
          target_entropy=3.0,
          initial_log_alpha=4.0,
          target_update_tau=0.5,
          actor_policy_ctor=DummyActorPolicy,
      )
  
      self.evaluate(
          [
              tf.compat.v1.global_variables_initializer(),
              tf.compat.v1.local_variables_initializer(),
          ]
      )
  
      self.evaluate(agent.initialize())
  
      for v in shared_layer.variables:
          self.evaluate(v.assign(v * 0 + 1))
  
      self.evaluate(agent._update_target())
  
      self.assertEqual(
          1.0, self.evaluate(shared_layer.variables[0][0][0])
      )
      self.assertEqual(
          0.5, self.evaluate(target_shared_layer.variables[0][0][0])
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import mock
  import tensorflow
  from tf_agents.agents import test_util
  from tf_agents.agents.ddpg import critic_rnn_network
  from tf_agents.agents.sac import sac_agent
  from tf_agents.agents.sac import tanh_normal_projection_network
  from tf_agents.networks import actor_distribution_network
  from tf_agents.networks import actor_distribution_rnn_network
  from tf_agents.networks import nest_map
  from tf_agents.networks import network
  from tf_agents.networks import sequential
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import policy_step
  from tf_agents.trajectories import time_step
  from tf_agents.trajectories import trajectory
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
label_desc: Use image node_id 12 for calling the SacAgentTest obj's underlying member method code with example usage: obj.testSharedLayer() without return types