Atari games have multiple logical episodes, one per life.

    However for metrics reporting we count full episodes all lives included.

def _fetch_atari_metrics(base_env):
    """Atari games have multiple logical episodes, one per life.

    However for metrics reporting we count full episodes all lives included.
    """
    unwrapped = base_env.get_unwrapped()
    if not unwrapped:
        return None
    atari_out = []
    for u in unwrapped:
        monitor = get_wrapper_by_cls(u, MonitorEnv)
        if not monitor:
            return None
        for eps_rew, eps_len in monitor.next_episode_results():
            atari_out.append(RolloutMetrics(eps_len, eps_rew, {}, {}, {}))
    return atari_out