How to use the vapoursynth.vpy_current_environment function in VapourSynth

def get_current_env() -> 'Environment':
    global _cur_env
    if _cur_env is None:
        import vapoursynth
        _cur_env = vapoursynth.vpy_current_environment
    try:
        _cur_env()
    except RuntimeError:
        return None

    return script.perform(lambda: vapoursynth.vpy_current_environment()).result()

    env = vss.get('ipython').perform(lambda: vs.vpy_current_environment()).result()
    with env: