anchor.diff:  
   init({InstanceName, FromTimestamp, SubPid}) ->
       link(SubPid),
  +    MRef=monitor(process, SubPid),
       ZList=logmachine:get_zlist(InstanceName, FromTimestamp),
       {ok, #state{instance=InstanceName,
                   zlist=ZList,
                   subscriber=SubPid,
  +                subscriber_mref=MRef,
                   last_from=FromTimestamp,mode=recover}, 1}.
   
  -handle_call(_Request, _From, State) ->
  +handle_call(_Request, _From, #state{}=State) ->
       {reply, unsupported, State}.
   
   handle_cast({Ts, _ }=HistoryEntry, 
  
positive.code: send_entries(SubPid, [{T,_}=E], _LastFrom) ->
      SubPid ! E, T;
  send_entries(SubPid, EntryList, LastFrom) ->
      zlists:foldl(fun({T,_}=E) -> SubPid ! E, T end, LastFrom, EntryList).
  
  
negative.code:     LastFrom1=send_entries(SubPid, L, LastFrom),
      % Update state with tail zlist and new timestamp
      {noreply, State#state{zlist=ZList1,last_from=LastFrom1}, 1};
  % Subscriber process terminated normaly, hence subscription session stops also (normaly)
  handle_info({'DOWN', MRef, process, _Object, _Info}, 
              #state{subscriber_mref=MRef}=State) ->
      {stop, normal, State};
  handle_info(_Info, #state{}=State) ->
      {noreply, State}.
  
  terminate(_Reason, _State) -> ok.
  