code: def policy(self, obs):
      hid = self.fc1(obs)
      means = self.fc2(hid)
      return means
  
file_path: PARL/examples/tutorials/lesson5/ddpg/model.py
imports: import paddle.fluid
  import parl
  from parl import layers
label_desc: Use image node_id 2 for calling the ActorModel obj's underlying member method code with example usage: obj.policy(obs) and returns: means