public function fetchAllContacts($seq = 0)
    {
        $url = sprintf($this->vbot->config['server.uri.base'].'/webwxgetcontact?pass_ticket=%s&skey=%s&r=%s&seq=%s',
            $this->vbot->config['server.passTicket'],
            $this->vbot->config['server.skey'],
            time(),
            $seq
        );

        $result = $this->vbot->http->json($url, [], true, ['timeout' => 60]);

        if (isset($result['MemberList']) && $result['MemberList']) {
            $this->store($result['MemberList']);
        }

        if (isset($result['Seq']) && $result['Seq'] != 0) {
            $this->fetchAllContacts($result['Seq']);
        }
    }