lookupPubKey method
Implementation
@visibleForTesting
String? lookupPubKey(String atSign, String enrollmentId) {
if (publicKeyCacheSettings == null) return null;
final key = _cacheKey(atSign, enrollmentId);
final cacheValue = pubKeyCache[key];
if (cacheValue == null) return null;
if (!DateTime.now().isBefore(cacheValue.$2)) {
pubKeyCache.remove(key);
return null;
}
return cacheValue.$1;
}