code: def render(self):
      self.env.render()
  
file_path: PARL/examples/tutorials/parl2_dygraph/lesson5/homework/ddpg_quadrotor/train.py
imports: import gym
  import parl
  import paddle
  import argparse
  import numpy
  from parl.utils import logger, tensorboard, ReplayMemory
  from quadrotor_model import QuadrotorModel
  from quadrotor_agent import QuadrotorAgent
  from parl.algorithms import DDPG
  from rlschool import make_env
  import paddle
label_desc: Use image node_id 4 for calling the ActionMappingWrapper obj's underlying member method code with example usage: obj.render() without return types