docs: public long getLastLoggedZxid() {
          File[] files = getLogFiles(logDir.listFiles(), 0);
          long maxLog=files.length>0?
                  Util.getZxidFromName(files[files.length-1].getName(),"log"):-1;
  
          // if a log file is more recent we must scan it to find
          // the highest zxid
          long zxid = maxLog;
          try {
              FileTxnLog txn = new FileTxnLog(logDir);
              TxnIterator itr = txn.read(maxLog);
              while (true) {
                  if(!itr.next())
                      break;
                  TxnHeader hdr = itr.getHeader();
                  zxid = hdr.getZxid();
              }
          } catch (IOException e) {
              LOG.warn("Unexpected exception", e);
          }
          return zxid;
      }