docs: public BigMoney convertedTo(CurrencyUnit currency, BigDecimal conversionMultipler) {
          MoneyUtils.checkNotNull(currency, "CurrencyUnit must not be null");
          MoneyUtils.checkNotNull(conversionMultipler, "Multiplier must not be null");
          if (this.currency == currency) {
              if (conversionMultipler.compareTo(BigDecimal.ONE) == 0) {
                  return this;
              }
              throw new IllegalArgumentException("Cannot convert to the same currency");
          }
          if (conversionMultipler.compareTo(BigDecimal.ZERO) < 0) {
              throw new IllegalArgumentException("Cannot convert using a negative conversion multiplier");
          }
          BigDecimal newAmount = amount.multiply(conversionMultipler);
          return BigMoney.of(currency, newAmount);
      }