code: public DecimalStyle withNegativeSign(char negativeSign) {
          if (negativeSign == this.negativeSign) {
              return this;
          }
          return new DecimalStyle(zeroDigit, positiveSign, negativeSign, decimalSeparator);
      }
docs: Returns a copy of the info with a new character that represents the negative sign.
  <p>
  The character used to represent a negative number may vary by culture.
  This method specifies the character to use.
  
  @param negativeSign  the character for the negative sign
  @return  a copy with a new character that represents the negative sign, not null