anchor.diff:  import 'package:http/http.dart' as http;
   import 'package:memcache/memcache.dart' as memcache;
   import 'package:memcache/memcache_raw.dart' as memcache_raw;
  +import 'package:path/path.dart' as p;
   
   import '../api/errors.dart' as errors;
   import '../api/logging.dart' as logging;
  
positive.code:   final instance = _findEnvironmentVariable('GAE_INSTANCE',
            onlyInProd: true, needed: true) ??
        'dummy-instance';
    final zoneId = 'dummy-zone';
  
    final String pubServeUrlString = Platform.environment['DART_PUB_SERVE'];
    final Uri pubServeUrl =
  
negative.code: /// returns a new [ContextRegistry] which is used for registering in-progress
  /// http requests.
  Future<ContextRegistry> _initializeAppEngine() async {
    var zoneId = await _getZoneInProduction();
    final isDevEnvironment = zoneId == null;
    zoneId ??= 'dev-machine';
    final bool isProdEnvironment = !isDevEnvironment;
  
    String _findEnvironmentVariable(String name,
  