anchor.diff:  		 file_system_pid = FileSystemPid,
   		 peer_process_dict = dict:new() }}.
   
  -
  +handle_call(choked, {Pid, _Tag}, S) ->
  +    {reply, ok, peer_dict_update(
  +		  Pid,
  +		  fun(PI) ->
  +			  PI#peer_info{
  +			    choking = true}
  +		  end,
  +		  S)};
  +handle_call(unchoked, {Pid, _Tag}, S) ->
  +    {reply, ok, peer_dict_update(
  +		  Pid,
  +		  fun(PI) ->
  +			  PI#peer_info{
  +			    choking = false}
  +		  end,
  +		  S)};
   handle_call({uploaded_data, Amount}, {Pid, _Tag}, S) ->
       {reply, ok, peer_dict_update(
   		  Pid,
  
positive.code: 
  peer_not_interested(Pid) ->
      gen_server:call(Pid, not_interested).
  
  %%====================================================================
  %% gen_server callbacks
  
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]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  