@NotNull
  @Override
  protected LinearGraphAnswer delegateGraphChanged(@NotNull LinearGraphAnswer delegateAnswer) {
    if (delegateAnswer.getGraphChanges() != null) {
      LinearGraph delegateGraph = getDelegateController().getCompiledGraph();
      myCollapsedGraph = CollapsedGraph.updateInstance(myCollapsedGraph, delegateGraph);

      // some new edges and node appeared, so we expand them
      applyDelegateChanges(delegateGraph, delegateAnswer.getGraphChanges());
    }
    return delegateAnswer; // if somebody outside actually uses changes we return here they are screwed
  }
@NotNull
  @Override
  protected LinearGraphAnswer delegateGraphChanged(@NotNull LinearGraphAnswer delegateAnswer)