anchor.diff:  %% @end
   -spec add_piece(torrent_id(), pos_integer(), pieceset()) -> ok.
   add_piece(TorrentID, Index, Pieceset) ->
  -    SrvPid = lookup_scarcity_server(TorrentID),
  +    SrvPid = lookup_server(TorrentID),
       gen_server:call(SrvPid, {add_piece, self(), Index, Pieceset}).
   
   
  
positive.code:     {N, Time, Pid}.
  
  register_case() ->
      true = ?scarcity:register_scarcity_server(0),
      ?assertEqual(self(), ?scarcity:lookup_scarcity_server(0)),
      ?assertEqual(self(), ?scarcity:await_scarcity_server(0)).
  
  server_registers_case() ->
      {ok, Pid} = ?scarcity:start_link(1, 16),
      ?assertEqual(Pid, ?scarcity:lookup_scarcity_server(1)).
  
  initial_ordering_case({N, Time, Pid}) ->
      {ok, Order} = ?scarcity:get_order(N, pieces([0,1,2,3,4,5,6,7])),
  
negative.code: -spec watch(torrent_id(), term(), pieceset(), pos_integer()) ->
      {ok, reference(), [pos_integer()]}.
  watch(TorrentID, Tag, Pieceset, Interval) ->
      SrvPid = lookup_server(TorrentID),
      gen_server:call(SrvPid, {watch, self(), Interval, Tag, Pieceset}).
  
  %% @doc Cancel updates to changes in scarcity
  