docs: public static BigDecimal logRangeTen(BigDecimal x, MathContext mathContext, BiFunction<BigDecimal, MathContext, BigDecimal> logFunction) {
  		// http://en.wikipedia.org/wiki/Natural_logarithm
  
  		if (x.signum() <= 0) {
  			throw new ArithmeticException("Illegal log(x) for x <= 0: x = " + x);
  		}
  		if (x.compareTo(ONE) == 0) {
  			return ZERO;
  		}
  
  		switch (x.compareTo(TEN)) {
  			case 0:
  				return logTen(mathContext);
  			case 1:
  				return logUsingExponent(x, mathContext, logFunction);
  		}
  
  		return logFunction.apply(x, mathContext);
  	}