@Override
        public Collection<CuratorTransactionResult> commit() throws Exception {
            fileSystem.replaceRoot(newRoot);
            committed = true;
            delayedListener.commit();
            return null; // TODO
        }
The new directory root in which the transactional changes are made
zkfacade/src/main/java/com/yahoo/vespa/curator/mock/MockCuratorFramework.java