anchor.diff:  
   %% API
   -export([start_link/4, add_peers/2, uploaded_data/2, downloaded_data/2,
  -	peer_interested/1, peer_not_interested/1]).
  +	peer_interested/1, peer_not_interested/1, peer_choked/1,
  +	peer_unchoked/1]).
   
   %% gen_server callbacks
   -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
positive.code: 		 file_system_pid = FileSystemPid,
  		 peer_process_dict = dict:new() }}.
  
  
  handle_call({uploaded_data, Amount}, {Pid, _Tag}, S) ->
      {reply, ok, peer_dict_update(
  		  Pid,
  
negative.code: 
  peer_not_interested(Pid) ->
      gen_server:call(Pid, not_interested).
  
  peer_choked(Pid) ->
      gen_server:call(Pid, choked).
  
  peer_unchoked(Pid) ->
      gen_server:call(Pid, unchoked).
  
  %%====================================================================
  %% gen_server callbacks
  