code: public static String formatBetween(long betweenMs, BetweenFormater.Level level) {
  		return new BetweenFormater(betweenMs, level).format();
  	}
docs: 格式化日期间隔输出
  
  @param betweenMs 日期间隔
  @param level 级别，按照天、小时、分、秒、毫秒分为5个等级
  @return XX天XX小时XX分XX秒XX毫秒