code: def test_monitor():
      """
      test the monitor wrapper
      """
      env = gym.make("CartPole-v1")
      env.seed(0)
      mon_file = "/tmp/stable_baselines-test-{}.monitor.csv".format(
          uuid.uuid4()
      )
      menv = Monitor(env, mon_file)
      menv.reset()
      for _ in range(1000):
          _, _, done, _ = menv.step(0)
          if done:
              menv.reset()
  
      file_handler = open(mon_file, "rt")
  
      firstline = file_handler.readline()
      assert firstline.startswith("#")
      metadata = json.loads(firstline[1:])
      assert metadata["env_id"] == "CartPole-v1"
      assert set(metadata.keys()) == {
          "env_id",
          "t_start",
      }, "Incorrect keys in monitor metadata"
  
      last_logline = pandas.read_csv(file_handler, index_col=None)
      assert set(last_logline.keys()) == {
          "l",
          "t",
          "r",
      }, "Incorrect keys in monitor logline"
      file_handler.close()
      os.remove(mon_file)
  
file_path: stable-baselines/tests/test_monitor.py
imports: import uuid
  import json
  import os
  import pandas
  import gym
  from stable_baselines.bench import Monitor
  from stable_baselines.bench.monitor import get_monitor_files, load_results
label_desc: Use image node_id 1 for calling a global function with example usage: test_monitor() without return types