anchor.diff:  
   is_empty(State) ->
       ?LOG({is_empty,State}),
  -    case length(State) of
  +    case dict:size(State) of
           0 ->
  -            {true, []};
  +            {true, State};
           Size ->
               {false, Size, State}
       end.
  
positive.code:     {stop, Reason, State}.
  
  handle_handoff_command(?FOLD_REQ{foldfun=FoldFun, acc0=Acc0}, _Sender, State) ->
      F = fun({Name, Address}, Acc) -> FoldFun(Name, Address, Acc) end,
      Acc = lists:foldl(F, Acc0, State),
      ?LOG({handoff_command, sending_data}),
      {reply, Acc, State};
  
  
negative.code: 
  %% vnode callbacks
  init([_Index]) ->
      {ok, dict:new()}.
  
  handle_command({add_contact, Name, Address}, Sender, State) ->
      ?LOG({add_contact, Name, Address, Sender}),
      {reply, ok, dict:store(Name, Address, State)};
  
  handle_command({find_contact, Name}, Sender, State) ->
      ?LOG({find_contact, Name, Sender}),
      case dict:find(Name, State) of
          {ok, Address} ->
              Reply = Address;
          error ->
              Reply = not_found
      end,
      ?LOG({result, Reply}),
      {reply, Reply, State};
  