code: private boolean resubscribe() throws TransactionIdTooOldException,
        InterruptedException {
      for (NamespaceEventKey eventKey : watchedEvents.keySet()) {
        NamespaceEvent event = eventKey.getEvent(); 
        if (!subscribe(event.getPath(), EventType.fromByteValue(event.getType()),
            watchedEvents.get(eventKey))) {
          return false;
        }
      }
      return true;
    }
docs: Called right after a reconnect to resubscribe to all events. Must be
  called with the connection lock acquired.