Find a sequence of sorted deduplicated IPv#Address.

    Args:
        addresses: a list of IPv#Address objects.

    Yields:
        A tuple containing the first and last IP addresses in the sequence.

def _find_address_range(addresses):
    """Find a sequence of sorted deduplicated IPv#Address.

    Args:
        addresses: a list of IPv#Address objects.

    Yields:
        A tuple containing the first and last IP addresses in the sequence.

    """
    it = iter(addresses)
    first = last = next(it)
    for ip in it:
        if ip._ip != last._ip + 1:
            yield first, last
            first = ip
        last = ip
    yield first, last