anchor.diff:  import 'encoding_constants.dart' as constants;
   import "reflectable_class_constants.dart" as reflectable_class_constants;
   import 'transformer_errors.dart' as errors;
  +
  +// Single source of instances of [Resolver], shared across multiple
  +// invocations of `apply` to save memory.
  +Resolvers _resolvers = new Resolvers(dartSdkDirectory);
   
   class ReflectionWorld {
     final List<_ReflectorDomain> reflectors = new List<_ReflectorDomain>();
  
positive.code:       Transform wrappedTransform =
            new _AggregateTransformWrapper(aggregateTransform, entryPointAsset);
  
        _resolver = await resolvers.get(wrappedTransform);
        LibraryElement reflectableLibrary =
            _resolver.getLibraryByName("reflectable.reflectable");
        if (reflectableLibrary == null) {
  
negative.code:     _logger = aggregateTransform.logger;
      // The type argument in the return type is omitted because the
      // documentation on barback and on transformers do not specify it.
  
      List<Asset> assets = await aggregateTransform.primaryInputs.toList();
  
  