public Decimal round(Double factor, int scale, RoundingMethod roundingMethod)
  {
	switch (roundingMethod)
	{
	case DOWN:
	  return roundDown(factor, scale);
	case UP:
	  return roundUp(factor, scale);
	case HALF_UP:
	  return roundHalfUp(factor, scale);

	default:
	  break;
	}
	return null;
  }