anchor.diff:      receive
   	die ->
   	    nil;
  -	{done, NumReceived} ->
  +	{mappers, done, NumReceived} ->
   	    Parent ! {self (), Dict};
   	Keys  ->
   	    reducer(Parent, add_keys(Dict, Keys), NumReceived + 1)
  
positive.code: 			   Reducer ! die,
  			   exit(Reason)
  		   end,
      Reducer ! {done, SentMessages},
      Results = receive
  		  {Reducer, Results2} ->
  		      Results2;
  
negative.code: cluster_runmany(Fun, Fuse, TaskList, Nodes, Running, Results) when length(Running) > 0 ->
      receive
  	{Pid, Num, Result} ->
  	    % throw out the exit message, Reason should be
  	    % normal, noproc, or noconnection
  	    receive {'DOWN', _, _, Pid, _Reason} ->
  		    nil
  	    end,
  	    {Running2, FinishedNode, _} = delete_running(Pid, Running, []),
  