@Override
    public void check(Curator curator, TransactionChanges changes) {
        if ( ! curator.exists(Path.fromString(path)) && ! changes.create(path) )
            throw new IllegalStateException("Cannot perform " + this + ": Path does not exist");
    }
ZooKeeper setData operation.

@author Ulf Lilleengen
@author bratseth
zkfacade/src/main/java/com/yahoo/vespa/curator/transaction/CuratorSetDataOperation.java