private function create_token($token) {
        global $CFG;

        if (!$this->is_system_configured()) {
            return false;
        }

        require_once($CFG->libdir . '/filelib.php');

        $serverurl = $CFG->airnotifierurl . ':' . $CFG->airnotifierport . '/tokens/' . $token;
        $header = array('Accept: application/json', 'X-AN-APP-NAME: ' . $CFG->airnotifierappname,
            'X-AN-APP-KEY: ' . $CFG->airnotifieraccesskey);
        $curl = new curl;
        $curl->setHeader($header);
        $params = array();
        $resp = $curl->post($serverurl, $params);

        if ($token = json_decode($resp, true)) {
            if (!empty($token['status'])) {
                return $token['status'] == 'ok' || $token['status'] == 'token exists';
            }
        }
        debugging("Unexpected response from the Airnotifier server: $resp");
        return false;
    }