public MonetaryFormat digits(char zeroDigit) {
        if (zeroDigit == this.zeroDigit)
            return this;
        else
            return new MonetaryFormat(negativeSign, positiveSign, zeroDigit, decimalMark, minDecimals, decimalGroups,
                    shift, roundingMode, codes, codeSeparator, codePrefixed);
    }
@Test
    public void testDigits() {
        assertEquals("١٢.٣٤٥٦٧٨٩٠", NO_CODE.digits('\u0660').format(Coin.valueOf(1234567890l)).toString());
    }