retrieve method
Implementation
Future<String> retrieve() async {
_CrlStatus status = _readLocal();
if (status.crl != null && !status.expired) {
return status.crl!;
}
return _fetch().then((crl) => _saveLocal(crl)).onError((error, stackTrace) {
if (status.crl != null) {
return status.crl!;
}
throw error!;
});
}