@NonNull
    public List<LogEntry> getLogs() {
        //if a cache was freshly loaded from server, it may not have the "logs" flag although logs exist in local db.
        return DataStore.loadLogs(geocode);
        //return inDatabase() ? DataStore.loadLogs(geocode) : Collections.emptyList();
    }
The list of logs is immutable, because it is directly fetched from the database on demand, and not stored at this
object. If you want to modify logs, you have to load all logs of the cache, create a new list from the existing
list and store that new list in the database.

@return immutable list of logs
main/src/main/java/cgeo/geocaching/models/Geocache.java