docs: protected boolean isLastTime(Date lastBackupTime) {
  		if (lastBackupTime == null) {
  			return true;
  		}
  		long diff = System.currentTimeMillis() - lastBackupTime.getTime();
  		if (diff > (this.getInterval() * 1000L)) {
  			// 10分钟前的时间算是上次备份时间
  			return true;
  		}
  		return false;
  	}