docs: public synchronized long nextId() {
  		long timestamp = genTime();
  		if (timestamp < lastTimestamp) {
  			// 如果服务器时间有问题(时钟后退) 报错。
  			throw new IllegalStateException(StrUtil.format("Clock moved backwards. Refusing to generate id for {}ms", lastTimestamp - timestamp));
  		}
  		if (lastTimestamp == timestamp) {
  			sequence = (sequence + 1) & sequenceMask;
  			if (sequence == 0) {
  				timestamp = tilNextMillis(lastTimestamp);
  			}
  		} else {
  			sequence = 0L;
  		}
  
  		lastTimestamp = timestamp;
  
  		return ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << datacenterIdShift) | (workerId << workerIdShift) | sequence;
  	}