How to use the tld.exceptions.TldDomainNotFound function in tld

:param str local_hostname: Hostname to use for generating the WPAD URLs.
        If not provided, the local hostname is used.
    :return: PAC URLs to try in order, according to the WPAD protocol.
        If the hostname isn't qualified or is otherwise invalid, an empty list is returned.
    :rtype: list[str]
    """
    if not local_hostname:
        local_hostname = socket.getfqdn()
    if '.' not in local_hostname or len(local_hostname) < 3 or \
            local_hostname.startswith('.') or local_hostname.endswith('.'):
        return []
    try:
        parsed = get_tld('http://' + local_hostname, as_object=True)
        subdomain, tld = parsed.subdomain, parsed.fld
    except TldDomainNotFound:
        final_dot_index = local_hostname.rfind('.')
        subdomain, tld = local_hostname[0:final_dot_index], local_hostname[final_dot_index+1:]
    return wpad_search_urls(subdomain, tld)

def validate_tld(value):
    try:
        tld.get_tld(value)
    except TldDomainNotFound:
        raise ValidationError('Invalid domain name')