public static Formatter forNumbers(@Nonnull String format) {
        return new NumberFormat(format);
    }
@Test
    public void testFillMode() {
        check(0,  " 0",  "-0",  "9");
        check(0,   "0",  "-0",  "FM9");

        check(0,  " 0 ",  "<0>",  "B9");
        check(0,   "0",   "<0>",  "FMB9");

        Formatter f = forNumbers("999 (RN)");
        check(0,   f, "   0 ()               ");
        check(988, f, " 988 (CMLXXXVIII)     ");
    }