docs: public long betweenYear(boolean isReset) {
  		final Calendar beginCal = DateUtil.calendar(begin);
  		final Calendar endCal = DateUtil.calendar(end);
  
  		int result = endCal.get(Calendar.YEAR) - beginCal.get(Calendar.YEAR);
  		if (false == isReset) {
  			endCal.set(Calendar.YEAR, beginCal.get(Calendar.YEAR));
  			long between = endCal.getTimeInMillis() - beginCal.getTimeInMillis();
  			if (between < 0) {
  				return result - 1;
  			}
  		}
  		return result;
  	}