public static Comparator<String> stringComparator(boolean ignoreCase) {
        if (ignoreCase) {
            if (icStrComparator == null) {
                icStrComparator = String.CASE_INSENSITIVE_ORDER;
            }

            return icStrComparator;
        }

        if (strComparator == null) {
            strComparator = Comparator.naturalOrder();
        }

        return strComparator;
    }
public static Comparator<String> stringComparator(boolean ignoreCase)