public static Formatter forNumbers(@Nonnull String format) {
        return new NumberFormat(format);
    }
@Test
    public void testFeatureOrthogonality() {
        Formatter f = forNumbers("FM999th +.99");
        check(421.35, f, "421st +.35");

        f = forNumbers("FM999.99th");
        check(421.35, f, "421.35st");

        f = forNumbers("FM999V99 -> RN");
        check(3.14,  f, "314 -> CCCXIV");
    }