anchor.diff:                      LastModified = httpd_util:rfc1123_date(FileInfo#file_info.mtime),
                       case get_header_value("if-modified-since") of
                           LastModified ->
  -                            respond({304, [], ""});
  +                            respond({304, ExtraHeaders, ""});
                           _ ->
                               case file:open(File, [raw, binary]) of
                                   {ok, IoDevice} ->
                                       ContentType = mochiweb_util:guess_mime(File),
  -                                    Res = ok({ContentType, [{"last-modified", LastModified}], {file, IoDevice}}),
  +                                    Res = ok({ContentType,
  +                                              [{"last-modified", LastModified}
  +                                               | ExtraHeaders],
  +                                              {file, IoDevice}}),
                                       file:close(IoDevice),
                                       Res;
                                   _ ->
  -                                    not_found()
  +                                    not_found(ExtraHeaders)
                               end
                       end;
                   {error, _} ->
  -                    not_found()
  +                    not_found(ExtraHeaders)
               end
       end.
   
  
positive.code:     Response.
  
  %% @spec not_found() -> response()
  %% @doc respond({404, [{"Content-Type", "text/plain"}], "Not found."}).
  not_found() ->
      respond({404, [{"Content-Type", "text/plain"}], <<"Not found.">>}).
  
  %% @spec ok({value(), iodata()} | {value(), ioheaders(), iodata() | {file, IoDevice}}) ->
  %%           response()
  
negative.code: %% @spec serve_file(Path, DocRoot) -> Response
  %% @doc Serve a file relative to DocRoot.
  serve_file(Path, DocRoot) ->
      serve_file(Path, DocRoot, []).
  
  %% @spec serve_file(Path, DocRoot, ExtraHeaders) -> Response
  %% @doc Serve a file relative to DocRoot.
  serve_file(Path, DocRoot, ExtraHeaders) ->
      case mochiweb_util:safe_relative_path(Path) of
          undefined ->
              not_found();
  