anchor.diff:  
   cache(Url, Pid, Ref) ->
       gen_server:cast(urlcache, {cache, Url, Pid, Ref}).
  +
  +current_downloads() ->
  +    gen_server:call(urlcache, current_downloads).
   
   %%---------------------------------------------------------------------------
   
  
positive.code: -define(CACHE_LIMIT_K, (1048576 * 2)).
  
  -export([start_link/0]).
  -export([cache/1, cache/3]).
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
  
  start_link() ->
  
negative.code: 	    wait_for_completion1(LocalFileName, Pid, Ref)
      end.
  
  collect_current_downloads([], Urls) ->
      Urls;
  collect_current_downloads([{{downloader, Url}, _Pid} | Rest], Urls) ->
      collect_current_downloads(Rest, [Url | Urls]);
  collect_current_downloads([_Other | Rest], Urls) ->
      collect_current_downloads(Rest, Urls).
  
  %%---------------------------------------------------------------------------
  
  init(_Args) ->
      {ok, none}.
  
  handle_call(current_downloads, _From, State) ->
      {reply, collect_current_downloads(get(), []), State}.
  
  handle_cast({cache, Url}, State) ->
      start_caching(Url),
  