public String getNode() {
    return this.node;
  }
Gets the data of the node.
<p>
If the node is currently available, the most up-to-date known version of the data is returned.
If the node is not currently available, null is returned.
@param refresh whether to refresh the data by calling ZK directly.
@return data of the node, null if unavailable
hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKNodeTracker.java