# File lib/openid/server.rb, line 446
      def encode_to_url(server_url)
        q = {
          'openid.mode' => @mode,
          'openid.identity' => @identity,
          'openid.return_to' => @return_to
        }

        q['openid.trust_root'] = @trust_root if @trust_root
        q['openid.assoc_handle'] = @assoc_handle if @assoc_handle
        return OpenID::Util.append_args(server_url, q)
      end