public static Comparator<Val> getComparator(final boolean isCaseSensitive) {
        return (o1, o2) ->
                compare(o1, o2, isCaseSensitive);
    }
@return True if val is not null and is not {@link ValNull#INSTANCE}
stroom-query/stroom-query-language/src/main/java/stroom/query/language/functions/ValComparators.java