code: public int getDefaultFractionDigits(CurrencyUsage Usage) {
          CurrencyMetaInfo info = CurrencyMetaInfo.getInstance();
          CurrencyDigits digits = info.currencyDigits(subType, Usage);
          return digits.fractionDigits;
      }
docs: Returns the number of the number of fraction digits that should
  be displayed for this currency with Usage.
  @param Usage the usage of currency(Standard or Cash)
  @return a non-negative number of fraction digits to be
  displayed