docs: def run_loop(agents, env, max_frames=0, max_episodes=0):
    """A run loop to have agents and an environment interact."""
    total_frames = 0
    total_episodes = 0
    start_time = time.time()
  
    observation_spec = env.observation_spec()
    action_spec = env.action_spec()
    for agent, obs_spec, act_spec in zip(agents, observation_spec, action_spec):
      agent.setup(obs_spec, act_spec)
  
    try:
      while not max_episodes or total_episodes < max_episodes:
        total_episodes += 1
        timesteps = env.reset()
        for a in agents:
          a.reset()
        while True:
          total_frames += 1
          actions = [agent.step(timestep)
                     for agent, timestep in zip(agents, timesteps)]
          if max_frames and total_frames >= max_frames:
            return
          if timesteps[0].last():
            break
          timesteps = env.step(actions)
    except KeyboardInterrupt:
      pass
    finally:
      elapsed_time = time.time() - start_time
      print("Took %.3f seconds for %s steps: %.3f fps" % (
          elapsed_time, total_frames, total_frames / elapsed_time))