anchor.diff:        return o.importExpr(_idFor(token.toTypeValue()));
       } else if (_isEnum(token.type)) {
         return _expressionForEnum(token);
  +    } else if (_isProtobufEnum(token.type)) {
  +      return _expressionForProtobufEnum(token);
       } else if (token.type is InterfaceType) {
         return _expressionForType(token);
       } else if (token.type.element is FunctionTypedElement) {
  
positive.code: 
    bool _isPositional(ParameterElement param) =>
        param.parameterKind == ParameterKind.POSITIONAL;
  }
  
negative.code:     as annotation_matcher;
  import 'package:angular2/src/source_gen/common/url_resolver.dart';
  import 'package:logging/logging.dart';
  import 'package:protobuf/protobuf.dart';
  import 'package:quiver/strings.dart' as strings;
  import 'package:source_gen/src/annotation.dart' as source_gen;
  
  