code: @Override
      public int compareTo(BigMoneyProvider other) {
          BigMoney otherMoney = of(other);
          if (currency.equals(otherMoney.currency) == false) {
              throw new CurrencyMismatchException(getCurrencyUnit(), otherMoney.getCurrencyUnit());
          }
          return amount.compareTo(otherMoney.amount);
      }
docs: Compares this monetary value to another.
  The compared values must be in the same currency.
  
  @param other  the other monetary value, not null
  @return -1 if this is less than , 0 if equal, 1 if greater than
  @throws CurrencyMismatchException if the currencies differ