How to use the nbxmpp.util.generate_id function in nbxmpp

def send_cert_request(con, to_jid):
    iq = nbxmpp.Iq('get', to=to_jid)
    id_ = generate_id()
    iq.setAttr('id', id_)
    pubkey = iq.setTag('pubkeys')
    pubkey.setNamespace(Namespace.PUBKEY_PUBKEY)
    con.connection.send(iq)
    return str(id_)

'port': port,
                'type': 'direct',
                'jid': self.ourjid,
                'priority': priority
            }
            hosts.add(my_ip)
            local_ip_cand.append(candidate)

        try:
            for addrinfo in socket.getaddrinfo(socket.gethostname(), None):
                addr = addrinfo[4][0]
                if not addr in hosts and not addr.startswith('127.') and \
                addr != '::1':
                    candidate = {
                        'host': addr,
                        'candidate_id': generate_id(),
                        'port': port,
                        'type': 'direct',
                        'jid': self.ourjid,
                        'priority': priority,
                        'initiator': self.file_props.sender,
                        'target': self.file_props.receiver
                    }
                    hosts.add(addr)
                    local_ip_cand.append(candidate)
        except socket.gaierror:
            pass # ignore address-related errors for getaddrinfo

        try:
            from netifaces import interfaces, ifaddresses, AF_INET, AF_INET6
            for ifaceName in interfaces():
                addresses = ifaddresses(ifaceName)

def _get_query_id(self, jid):
        query_id = generate_id()
        self._mam_query_ids[jid] = query_id
        return query_id

def add_stanza(self, stanza, is_message=False):
        if self.Connection:
            if self.Connection.state == -1:
                return False
            self.send(stanza, is_message)
        else:
            self.stanzaqueue.append((stanza, is_message))

        if is_message:
            thread_id = stanza.getThread()
            id_ = stanza.getID()
            if not id_:
                id_ = generate_id()
            if self.fd in self.conn_holder.ids_of_awaiting_messages:
                self.conn_holder.ids_of_awaiting_messages[self.fd].append((id_,
                    thread_id))
            else:
                self.conn_holder.ids_of_awaiting_messages[self.fd] = [(id_,
                    thread_id)]

        return True

def set_connection(self, conn):
        self.connection = conn
        if not self.sid:
            self.sid = generate_id()

def build_message_stanza(self, message):
        own_jid = self._con.get_own_jid()

        stanza = nbxmpp.Message(to=message.jid,
                                body=message.message,
                                typ=message.type_,
                                subject=message.subject,
                                xhtml=message.xhtml)

        if message.correct_id:
            stanza.setTag('replace', attrs={'id': message.correct_id},
                          namespace=Namespace.CORRECT)

        # XEP-0359
        message.message_id = generate_id()
        stanza.setID(message.message_id)
        stanza.setOriginID(message.message_id)

        if message.label:
            stanza.addChild(node=message.label)

        # XEP-0172: user_nickname
        if message.user_nick:
            stanza.setTag('nick', namespace=Namespace.NICK).setData(
                message.user_nick)

        # XEP-0203
        # TODO: Seems delayed is not set anywhere
        if message.delayed:
            timestamp = time.strftime('%Y-%m-%dT%H:%M:%SZ',
                                      time.gmtime(message.delayed))