anchor.diff:  state_change(_Id, []) ->
       ok;
   state_change(Id, [What | Rest]) ->
  +    %% @todo Be more protective here
       [T] = ets:lookup(?TAB, Id),
       New = case What of
                 unknown ->
  
positive.code:             ok
      end,
      state_change(Id, Rest).
  
negative.code:     Q = all(#torrent.id),
      {reply, Q, S};
  handle_call({num_pieces, Id}, _F, S) ->
      Reply = case ets:lookup(?TAB, Id) of
  		[R] -> {value, R#torrent.pieces};
  		[] ->  not_found
  	    end,
      {reply, Reply, S};
  handle_call({statechange, Id, What}, _F, S) ->
      Q = state_change(Id, What),
      {reply, Q, S};
  