code: import time
  
  import numpy as np
  
  from metadrive import MetaDriveEnv
  from metadrive.utils import setup_logger
  
  if __name__ == '__main__':
      print("Start to profile the efficiency of MetaDrive with 1000 maps and ~8 vehicles!")
      setup_logger(debug=False)
      env = MetaDriveEnv(dict(
          environment_num=1000,
          start_seed=1010,
      ))
      obs = env.reset()
      start = time.time()
      action = [0.0, 1.]
      total_steps = 10000
      vehicle_num = [len(env.engine.traffic_manager.vehicles)]
      for s in range(total_steps):
          o, r, d, i = env.step(action)
          if d:
              env.reset()
              vehicle_num.append(len(env.engine.traffic_manager.vehicles))
          if (s + 1) % 100 == 0:
              print(
                  "Finish {}/10000 simulation steps. Time elapse: {:.4f}. Average FPS: {:.4f}, Average number of "
                  "vehicles: {:.4f}".format(
                      s + 1,
                      time.time() - start, (s + 1) / (time.time() - start), np.mean(vehicle_num)
                  )
              )
      print(
          "Total Time Elapse: {:.3f}, average FPS: {:.3f}, average number of vehicles: {:.3f}.".format(
              time.time() - start, total_steps / (time.time() - start), np.mean(vehicle_num)
          )
      )
  
apis: numpy.mean