docs: static public TimePeriod from(String quantityAndUnit) {
  		String trimed = quantityAndUnit.trim();
  		String allExceptLast = trimed.substring(0, trimed.length() - 1);
  		if (StringUtils.isNumericSpace(allExceptLast)){ // short format
  			long quantity = Long.parseLong(allExceptLast.trim());
  			TimePeriodUnit unit = TimePeriodUnit.from(Character.toUpperCase(trimed.charAt(trimed.length() - 1)));
  			return new TimePeriod(quantity, unit);
  		}else{
  			String[] durationAndUnit = StringUtils.split(trimed);
  			Long duration = Long.valueOf(durationAndUnit[0]);
  			TimePeriodUnit unit = TimePeriodUnit.from(durationAndUnit[1]);
  			return new TimePeriod(duration, unit);
  		}
  	}