anchor.diff:  %% This module provides a common interface for processes
   %% handling piece state changes.
   
  --export([stored/2,
  +-export([begun/2,
  +         stored/2,
            valid/2]).
  +
  +-type pieceindex() :: etorrent_types:pieceindex().
   
   %% @doc
   %% @end
  --spec stored(non_neg_integer(), pid()) -> ok.
  +-spec begun(pieceindex(), pid()) -> ok.
  +begun(Piece, Srvpid) ->
  +    Srvpid ! {piece, {begun, Piece}},
  +    ok.
  +
  +
  +%% @doc
  +%% @end
  +-spec stored(pieceindex(), pid()) -> ok.
   stored(Piece, Srvpid) ->
       Srvpid ! {piece, {stored, Piece}},
       ok.
  
positive.code: 
  %% @doc
  %% @end
  -spec valid(non_neg_integer(), pid()) -> ok.
  valid(Piece, Srvpid) ->
      Srvpid ! {piece, {valid, Piece}},
      ok.
  
negative.code: -ifdef(TEST).
  -include_lib("eunit/include/eunit.hrl").
  -define(piecestate, ?MODULE).
  
  begun_test() ->
      ?assertEqual(ok, ?piecestate:begun(0, self())),
      ?assertEqual({piece, {begun, 0}}, etorrent_utils:first()).
  
  stored_test() ->
      ?assertEqual(ok, ?piecestate:stored(0, self())),
  