public static Formatter forNumbers(@Nonnull String format) {
        return new NumberFormat(format);
    }
@Test
    public void testRounding() {
        Formatter f = forNumbers("FM0.9");
        check(0.15, f, "0.2");

        f = forNumbers("FM.99");
        check(0.015, f, ".02");

        f = forNumbers("FM99");
        check(9.9, f, "10");
    }