def METHOD_NAME(notifier: Notifier) -> None:
    """
    register internal notifiers
    """
    notifier.initialize()
    _notifiers.append(notifier)
    subscribed_message_types: List[
        Type[MessageBase]
    ] = notifier._subscribed_message_type()
    for message_type in subscribed_message_types:
        registered_notifiers = _messages.get(message_type, [])
        registered_notifiers.append(notifier)
        _messages[message_type] = registered_notifiers
    log = _get_init_logger()
    log.debug(
        f"registered [{notifier.type_name()}] "
        f"on messages: {[x.type for x in subscribed_message_types]}"
    )