Path is baked in. Entry is private. Dispatcher can change.

```
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] Flow (Parent) ...................................... SUCCESS [  0.276 s]
[INFO] Flow ............................................... SUCCESS [  3.890 s]
[INFO] Flow Sample ........................................ SUCCESS [  9.570 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 14.663 s
[INFO] Finished at: 2014-11-08T18:41:12-08:00
[INFO] Final Memory: 64M/719M
[INFO] ------------------------------------------------------------------------
```
No. The oustanding traversal is from A to B, and its callback has already been handed to another dispatcher. That dispatcher is still responsible for calling onComplete. But that hanging traveral has a blank next field, so the new dispatcher isn't going to hear anything about the current state. We create a bootstrap traversal from B to B for that guy. 

We never double-report traversals.