private void checkNumeric() {
if (width != -1 && width < 0)
throw new IllegalFormatWidthException(width);
if (precision != -1 && precision < 0)
throw new IllegalFormatPrecisionException(precision);
// '-' and '0' require a width
if (width == -1
&& (f.contains(Flags.LEFT_JUSTIFY) || f
.contains(Flags.ZERO_PAD)))