anchor.diff:  
       % N fastest interesteds should be kept
       {Downloaders, Rest} =
  -	find_fastest_downloaders(?DEFAULT_NUM_DOWNLOADERS,
  -			   Interested),
  +	find_fastest_peers(?DEFAULT_NUM_DOWNLOADERS,
  +			   Interested, S),
       unchoke_peers(Downloaders),
   
       % All peers not interested should be unchoked
  
positive.code: handle_cast({got_piece_from_peer, Index}, S) ->
      broadcast_have_message(Index, S),
      {noreply, S};
  handle_cast(_Msg, State) ->
      {noreply, State}.
  
  
negative.code: %% API
  -export([start_link/4, add_peers/2, uploaded_data/2, downloaded_data/2,
  	peer_interested/1, peer_not_interested/1, peer_choked/1,
  	peer_unchoked/1, got_piece_from_peer/2, new_incoming_peer/2,
  	seed/1]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  