public synchronized byte[] blockUntilAvailable() throws InterruptedException {
    return blockUntilAvailable(0, false);
  }
Gets the data of the node, blocking until the node is available.
@return data of the node
@throws InterruptedException if the waiting thread is interrupted
hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKNodeTracker.java