@Override
  public Delta createDelta(Iterable<NodeSource> sourcesToProcess, Iterable<NodeSource> deletedSources, boolean isSourceOnly) throws IOException {
    return getDelegate().createDelta(sourcesToProcess, deletedSources, isSourceOnly);
  }
@Override
  public Delta createDelta(Iterable<NodeSource> sourcesToProcess, Iterable<NodeSource> deletedSources, boolean isSourceOnly)