anchor.diff:  			ets:delete(?TAB, XNestName),
   			ets:delete(?PID_INDEX, Pid);
   		_ -> ok
  -	end
  +	end.
  
positive.code: %% @private
  init([]) ->
  	?TAB = ets:new(?TAB, [private, named_table]),
  	?PID_INDEX = ets:new(?TAB_INDEX, [private, named_table]),
  	process_flag(trap_exit, true),
  	{ok, #state{}}.
  
  %% @private
  handle_call({get_xnext, XNestName}, _From,  State=#state{monitors=Monitors}) ->
  	XNest = case ets:lookup(?TAB, XNestName) of
  		[{_XNestName, ExistXNest}|_] ->
  			ExistXNest;
  		_ ->
  			{ok, NewXNest} = xnest:start_link(),
  			ets:insert(?TAB, [{XnestName, NewXNest}]),
  			ets:insert(?PID_INDEX, [{NewXNest, XNestName}]),
  			NewXNest	
  	end,
  	{reply, XNest, State#state{monitors=NewMonitors}};
  handle_call(_Request, _From, State) ->
  	{reply, ignored, State}.
  
  
negative.code: handle_info({'EXIT', FromPid, normal}, State) ->
  	remove_xnest(FromPid),
          {noreply, State};
  handle_info({'EXIT', FromPid, _Reason}, State) ->
  	%% Temporarilly. Unnormal exit should be processed by 'ETS-TRANSFER'.
  	remove_xnest(FromPid),
          {noreply, State};
  handle_info({'ETS-TRANSFER', _Tid, FromPid, _HeirData}, State) ->
  	remove_xnest(FromPid),
  	%% Use tid start a new xnest.
  	{noreply, State};
  handle_info(_Info, State) ->
  	{noreply, State}.
  