def _formatting_rule_has_first_group_only(national_prefix_formatting_rule):
    if national_prefix_formatting_rule is None:
        return True
    return bool(fullmatch(_FIRST_GROUP_ONLY_PREFIX_PATTERN,
                          national_prefix_formatting_rule))
Add a node number to the list of link-layer nodes.
dataset/ETHPy150Open daviddrysdale/python-phonenumbers/python/phonenumbers/phonenumberutil.py/_formatting_rule_has_first_group_only--crossover with--dataset/ETHPy150Open coreemu/core/daemon/core/broker.py/CoreBroker.addnet