anchor.diff:        {reply, group_already_exists, State}
     end;
   
  -
   handle_call({rebuild, Group}, _From, State) ->
     case dict:find(Group, State) of
       {ok, {AssetPath, Tree, Options}} ->
  
positive.code: 
  -export([start_link/0]).
  -export([rebuild/1, watch/2]).
  -export([init/1, handle_call/3]).
  
  
  rebuild(Group) ->
  
negative.code:   {ok, dict:new()}.
  
  
  handle_call(stop, _From, State) ->
    {stop, normal, stopped, State};
  
  
  handle_call({watch, Group, AssetPath, Options}, _From, State) ->
    case dict:find(Group, State) of
      error ->
  