title: ordering sequential cancellations of multiple tasks in different actors
body: <p>Actors rely on Cancellation Token for cancelling task which can be wrapped in Cancellation Token Source.  When there are chain of actors in this single work flow, the cancellation request can propagate to this chain of actors in work.</p>
  
  <p>Probably each cancel task in each actor can be registered to the token for different work to be done before terminating the unfinished works.</p>
  
  <p>The scenario is such that this chain of works better be terminated in reverse order in such that the latest worker actor spawned, for example sending batch works updating database, better be cancelling its work before its parent actor throw cancellation exception.  At least to me this plan seems safer bet than just throw cancellation exception at the actor very top of this chain of works.</p>
  
  <p>I was thinking somehow registering these cancellation works in reverse order(such as using stack)  such that the very last cancellation delegate registered executes and then followed by the one registered as the second latest and so on.</p>
  
  <p>Using Combine Delegates or Stack with handlers are the considerations, please let me know / correct me to guide me into right direction.</p>