@Override
  public Set<URI> listChilden(URI uri) {

    // the length of this uri
    int ulen = CoreFS2Utils.getPathAsArray(uri).length;

    // remove descendants
    Set<URI> children = new HashSet<URI>();

    for (URI candidate : objectResolver.keySet()) {
      if (!candidate.equals(uri) && candidate.toString().startsWith(uri.toString())) {
        // also needs to be direct child
        int clen = CoreFS2Utils.getPathAsArray(candidate).length;
        if (clen == ulen + 1) {
          children.add(candidate);
        }
      }
    }
    return children;
  }