code: public void setMaximumFractionDigits(int newValue) {
          maximumFractionDigits = Math.max(0,newValue);
          if (maximumFractionDigits < minimumFractionDigits) {
              minimumFractionDigits = maximumFractionDigits;
          }
      }
docs: Sets the maximum number of digits allowed in the fraction portion of a
  number. maximumFractionDigits must be >= minimumFractionDigits.  If the
  new value for maximumFractionDigits is less than the current value
  of minimumFractionDigits, then minimumFractionDigits will also be set to
  the new value.
  @param newValue the maximum number of fraction digits to be shown; if
  less than zero, then zero is used. The concrete subclass may enforce an
  upper limit to this value appropriate to the numeric type being formatted.
  @see #getMaximumFractionDigits