docs: public MoneyAmountStyle withZeroCharacter(Character zeroCharacter) {
          int zeroVal = (zeroCharacter == null ? -1 : zeroCharacter);
          if (zeroVal == this.zeroCharacter) {
              return this;
          }
          return new MoneyAmountStyle(
                  zeroVal,
                  positiveCharacter, negativeCharacter,
                  decimalPointCharacter, groupingStyle,
                  groupingCharacter, groupingSize, extendedGroupingSize, forceDecimalPoint, absValue);
      }