anchor.diff:  shelf.Handler _requestContextWrapper(shelf.Handler handler) {
     return (shelf.Request request) async {
       final host = request.requestedUri.host;
  +    final isPrimaryHost = host == urls.primaryHost;
       final isProductionHost = activeConfiguration.productionHosts.contains(host);
       final isPubDev = host == 'pub.dev';
   
  
positive.code: import 'configuration.dart';
  import 'handlers.dart';
  import 'markdown.dart';
  import 'utils.dart' show fileAnIssueContent, parseCookieHeader;
  
  const _hstsDuration = Duration(minutes: 15);
  
negative.code: 
      final enableRobots = hasExperimentalCookie ||
          (!activeConfiguration.blockRobots && isProductionHost);
      final uiCacheEnabled = isPrimaryHost && !hasExperimentalCookie;
  
      registerRequestContext(RequestContext(
        isExperimental: isExperimental,
  