class_docstr: PG class
docstr: save trained weights
  :return: None
docstr_tok: ["save","trained","weights",":","return",":","None"]
code: def save(self):
      """
      save trained weights
      :return: None
      """
      path = os.path.join("model", "_".join([ALG_NAME, ENV_ID]))
      if not os.path.exists(path):
          os.makedirs(path)
      tl.files.save_weights_to_hdf5(
          os.path.join(path, "pg_policy.hdf5"), self.model
      )
  
file_path: TensorLayer/examples/reinforcement_learning/tutorial_PG.py
imports: import argparse
  import os
  import time
  import gym
  import matplotlib.pyplot
  import numpy
  import tensorflow
  import tensorlayer
label_desc: Use image node_id 6 for calling the PolicyGradient obj's underlying member method code with example usage: obj.save() without return types