anchor.diff:      Pid = spawn_link(scanner, scan_dir, [Dir, self()]),
       {noreply, State#state{scanner=Pid}}.
   
  +handle_call(stats, _From, State) ->
  +    NumFiles = proplists:get_value(size, dets:info(State#state.fdb), -1),
  +    {reply, [{num_files, NumFiles}], State};
  +    
   handle_call(_Msg, _From, State) -> {reply, ok, State}.
   
   handle_info({'EXIT', Pid, Reason}, #state{scanner = Pid} = State) ->
  
positive.code: targettime(_Pid)        -> 20.
  name(_Pid)              -> "Local Library using DETS".
  
  %%
  
  init([]) ->
  
negative.code: 
  %% API
  -export([start_link/0, resolve/3, weight/1, targettime/1, name/1]).
  -export([scan/2, stats/1 ]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
  