public function performRemoteCheck($httpClient = null) {
        if(empty($this->sessionToken)) { return false; }

        $json = $this->fetchUrl($this->getSessionCheckUrl(), $httpClient);
        if ($json) {
            $response = json_decode($json,true);

            if ($response['valid'] == "true" && $response['recheck'] != null) {
                $this->recheck = new DateTime($response['recheck']);
                return true;
            }
        }

        return false;
    }