docs: public static BigDecimal log(BigDecimal x, MathContext mathContext) {
  		checkMathContext(mathContext);
  		if (x.signum() <= 0) {
  			throw new ArithmeticException("Illegal log(x) for x <= 0: x = " + x);
  		}
  		if (x.compareTo(ONE) == 0) {
  			return ZERO;
  		}
  		
  		BigDecimal result;
  		switch (x.compareTo(TEN)) {
  		case 0:
  			result = logTen(mathContext);
  			break;
  		case 1:
  			result = logUsingExponent(x, mathContext);
  			break;
  		default :
  			result = logUsingTwoThree(x, mathContext);
  		}
  
  		return round(result, mathContext);
  	}