try {
        $client->listSessions();
    }catch (\BaiduBce\Exception\BceBaseException $e) {
        print $e->getMessage();
        if (stcmp(gettype($e), "BceClientException") == 0) {
            print "Catch a client exception";
        }
        if (stcmp(gettype($e), "BceServerException") == 0) {
            print "Catch a server exception";
        }
    }