@SuppressWarnings("unused")
    private void childEvent(CuratorFramework ignored, PathChildrenCacheEvent event) {
        zkWatcherExecutor.execute(() -> {
            log.log(Level.FINE, () -> "Got child event: " + event);
            switch (event.getType()) {
                case CHILD_ADDED, CHILD_REMOVED, CONNECTION_RECONNECTED -> sessionsChanged();
            }
        });
    }
A session for which we don't have a watcher, i.e. hitherto unknown to us.

@param sessionId session id for the new session
configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionRepository.java