docs: public static Rounding getInheritedRoundingMode(AbstractCalculator calc, Num value) {
          if (value.getRoundingMode() == null) {
              if (calc != null && calc.getRoundingMode() != null)
                  return calc.getRoundingMode();
              else
                  return Properties.defRoundingMode;
          }
          else
              return value.getRoundingMode();
      }