anchor.diff:  -behaviour(gen_server).
   
   %% API
  --export([start_link/6, connect/2, choke/1, unchoke/1]).
  --export([send_message/2]). % TODO: Make this local
  +-export([start_link/6, connect/2, choke/1, unchoke/1, interested/1]).
   
   %% gen_server callbacks
   -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
positive.code: 
  unchoke(Pid) ->
      gen_server:cast(Pid, unchoke).
  %%====================================================================
  %% gen_server callbacks
  %%====================================================================
  
negative.code: handle_cast(unchoke, S) ->
      torrent_peer_send:unchoke(S#state.send_pid),
      {noreply, S};
  handle_cast(interested, S) ->
      case S#state.local_interested of
  	true ->
  	    {noreply, S};
  	false ->
  	    send_message(interested, S),
  	    {noreply, S#state{local_interested = true}}
      end;
  handle_cast(_Msg, State) ->
      {noreply, State}.
  
  