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