def _is_valid_region_code(region_code):
    """Helper function to check region code is not unknown or None"""
    if region_code is None:
        return False
    return (region_code == SUPPORTED_REGIONS)
dataset/ETHPy150Open daviddrysdale/python-phonenumbers/python/phonenumbers/phonenumberutil.py/_is_valid_region_code/operator `in` -> `==`