anchor.diff:  }
   
   bool isNotModified(shelf.Request request, DateTime lastModified, String etag) {
  -  final ifModifiedSince = request.ifModifiedSince;
  -  if (ifModifiedSince != null &&
  -      lastModified != null &&
  -      !lastModified.isAfter(ifModifiedSince)) {
  -    return true;
  -  }
  +  try {
  +    final ifModifiedSince = request.ifModifiedSince;
  +    if (ifModifiedSince != null &&
  +        lastModified != null &&
  +        !lastModified.isAfter(ifModifiedSince)) {
  +      return true;
  +    }
   
  -  final ifNoneMatch = request.headers[HttpHeaders.ifNoneMatchHeader];
  -  if (ifNoneMatch != null && ifNoneMatch == etag) {
  -    return true;
  +    final ifNoneMatch = request.headers[HttpHeaders.ifNoneMatchHeader];
  +    if (ifNoneMatch != null && ifNoneMatch == etag) {
  +      return true;
  +    }
  +  } catch (e, st) {
  +    // TODO: remove after https://github.com/dart-lang/http_parser/issues/24 gets fixed
  +    _logger.info('HTTP Header parsing issue detected.', e, st);
     }
   
     return false;
  
positive.code: /// The age the browser should cache the static file if there is a hash provided
  /// and it matches the etag.
  const staticLongCache = const Duration(hours: 24);
  
  shelf.Response redirectResponse(String url) => new shelf.Response.seeOther(url);
  
  
negative.code: import 'dart:convert';
  import 'dart:io';
  
  import 'package:logging/logging.dart';
  import 'package:shelf/shelf.dart' as shelf;
  
  import 'popularity_storage.dart';
  