code: def main(argv):
      # Make sure tf does not allocate gpu memory.
      tf.config.experimental.set_visible_devices([], "GPU")
      config = FLAGS.config
      game = config.game + "NoFrameskip-v4"
      num_actions = env_utils.get_num_actions(game)
      print(f"Playing {game} with {num_actions} actions")
      model = models.ActorCritic(num_outputs=num_actions)
      ppo_lib.train(model, config, FLAGS.workdir)
  
imports: from absl import app
  from absl import flags
  from ml_collections import config_flags
  import tensorflow
  import env_utils
  import models
  import ppo_lib
label_desc: Use image node_id 1 for calling a global function with example usage: main(argv) without return types