docs: public void sync(final String path, VoidCallback cb, Object ctx) {
          verbotenThreadCheck();
          final String clientPath = path;
          PathUtils.validatePath(clientPath);
  
          final String serverPath = prependChroot(clientPath);
  
          RequestHeader h = new RequestHeader();
          h.setType(ZooDefs.OpCode.sync);
          SyncRequest request = new SyncRequest();
          SyncResponse response = new SyncResponse();
          request.setPath(serverPath);
          cnxn.queuePacket(h, new ReplyHeader(), request, response, cb,
                  clientPath, serverPath, ctx, null);
      }