anchor.diff:    final _HttpClient _httpClient;
     final _HttpClientConnection _httpClientConnection;
     final TimelineTask? _timeline;
  +  final TimelineTask? _responseTimeline;
   
     final Completer<HttpClientResponse> _responseCompleter =
         new Completer<HttpClientResponse>();
  
positive.code:     var proto = headers['x-forwarded-proto'];
      var scheme = proto != null
          ? proto.first
          : _httpConnection._socket is SecureSocket ? "https" : "http";
      var hostList = headers['x-forwarded-host'];
      String host;
      if (hostList != null) {
  
negative.code:       return;
      }
      final response =
          _HttpClientResponse(incoming, this, _httpClient, _responseTimeline);
      Future<HttpClientResponse> future;
      if (followRedirects && response.isRedirect) {
        if (response.redirects.length < maxRedirects) {
  