private CompletionWaiter getCompletionWaiter(Path path) {
        return curator.getCompletionWaiter(path, serverId, barrierWaitForAllTimeout);
    }
Zookeeper client for a specific session. Path for a session is /config/v2/tenants/&lt;tenant&gt;/sessions/&lt;sessionid&gt;
Can be used to read and write session status and create and get prepare and active barrier.

@author Ulf Lilleengen
configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java