anchor.diff:  
   -spec start_link(torrent_id(), file_path(), file_path()) -> {'ok', pid()}.
   start_link(TorrentID, Path, FullPath) ->
  -    gen_server:start_link(?MODULE, [TorrentID, Path, FullPath], []).
  +    gen_server:start_link(?MODULE, [TorrentID, Path, FullPath], [{fullsweep_after, 0}]).
   
   -spec open(pid()) -> 'ok'.
   open(FilePid) ->
  
positive.code:     NewState = State#state{handle=closed},
      {noreply, NewState}.
  
  handle_info(_, _) ->
      not_implemented.
  
  terminate(_, _) ->
      not_implemented.
  
negative.code: handle_call({read, Offset, Length}, _, State) ->
      #state{handle=Handle} = State,
      {ok, Chunk} = file:pread(Handle, Offset, Length),
      {reply, {ok, Chunk}, State, ?GC_TIMEOUT};
  handle_call({write, Offset, Chunk}, _, State) ->
      #state{handle=Handle} = State,
      ok = file:pwrite(Handle, Offset, Chunk),
      {reply, ok, State, ?GC_TIMEOUT}.
  
  handle_cast(open, State) ->
      #state{
  