anchor.diff:  %% API
   -export([
             get_url/1,
  +          get_redirect_url/1,
             parse_xml/1
           ]).
   
  
positive.code: %%====================================================================
  %%% Internal functions
  %%====================================================================
  
negative.code: get_url(Url) ->
      HttpDoc = http:request(get, {Url, headers()}, [], []),
      case HttpDoc of
          {ok, {{_,200,_}, _Headers, Body}} -> 
              Body;
          _ -> 
              {error}
      end.
  
  %%--------------------------------------------------------------------
  %% Func: get_redirect_url/1
  %% Description: return redirect URL.
  %%--------------------------------------------------------------------
  get_redirect_url(Url) ->
      HttpDoc = http:request(get, {Url, headers()}, [{autoredirect, false}], []),
      case HttpDoc of
          {ok, {{_,301,_}, Headers, _}} -> 
              get_location_from_headers(Headers);
          _ -> 
              {error}
      end.
  
  %%--------------------------------------------------------------------
  %% Func: headers/0
  %% Description: build request headers.
  %%--------------------------------------------------------------------
  headers() -> [{"User-Agent", "web.gnos.us/0.0"}].
  
  %%--------------------------------------------------------------------
  %% Func: parse_xml/1
  