private final GenericObject getProvHistory(final int id) {
        GenericObject hist = historyCache.get(id);
        if (hist == null) {
            String histFile = resolver.getProvinceHistoryFile(id);
            
            if (histFile == null) {
                System.err.println("Cannot find province history file for ID " + id);
                return null;
            }
            
            hist = EUGFileIO.load(histFile, settings);
            
            if (hist == null) {
                System.err.println("Failed to load province history file for ID " + id);
            } else {
//                java.util.Collections.sort(hist.children, DATE_OBJECT_COMPARATOR);
                historyCache.put(id, hist);
            }
        }
        return hist;
    }