def _is_valid_region_code(region_code):
    if region_code is None:
        return False
    return (region_code in SUPPORTED_REGIONS)
Called by the stream when it has started.
dataset/ETHPy150Open daviddrysdale/python-phonenumbers/python/phonenumbers/phonenumberutil.py/_is_valid_region_code--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/words/protocols/jabber/component.py/ListenComponentAuthenticator.streamStarted