code: public T divide(T divisor) {
          if (divisor == null) {
              throw new IllegalArgumentException("invalid (null) divisor");
          }
          BigDecimal quotient = this.value.divide(divisor.value, ROUND_BEHAVIOR);
  
          return newInstance(quotient, this.value.scale());
      }
docs: Wraps BigDecimal's divide method to enforce the default rounding
  behavior
  
  @param divisor the value to divide by
  @return result of dividing this value by the given divisor
  @throws IllegalArgumentException if the given divisor is null