code: def policy_sample(self, obs):
      feed = {"obs": obs}
      sampled_act = self.fluid_executor.run(
          self.policy_sample_program,
          feed=feed,
          fetch_list=self.policy_sample_output,
      )[0]
      return sampled_act
  
file_path: PARL/benchmark/fluid/PPO/mujoco_agent.py
imports: import numpy
  import parl
  from parl import layers
  from paddle import fluid
  from parl.utils import logger
label_desc: Use image node_id 3 for calling the MujocoAgent obj's underlying member method code with example usage: obj.policy_sample(obs) and returns: sampled_act