code: public byte[] getData(String path, Stat stat, Watcher watcher)
      throws KeeperException.NoNodeException {
          return dataTree.getData(path, stat, watcher);
      }
docs: get data and stat for a path
  @param path the path being queried
  @param stat the stat for this path
  @param watcher the watcher function
  @return
  @throws KeeperException.NoNodeException