anchor.diff:  import 'dart:async';
   import 'dart:developer' as developer;
   import 'package:analyzer/dart/ast/ast.dart';
  +import 'package:analyzer/dart/constant/value.dart';
   import 'package:analyzer/dart/element/element.dart';
   import 'package:analyzer/dart/element/type.dart';
   import 'package:analyzer/src/dart/element/element.dart';
   import 'package:analyzer/src/dart/element/type.dart';
  -import 'package:analyzer/src/generated/constant.dart';
  +import 'package:analyzer/src/dart/constant/evaluation.dart';
  +import 'package:analyzer/src/dart/constant/value.dart';
   import 'package:analyzer/src/generated/source.dart' show Source;
   import 'package:analyzer/src/generated/utilities_dart.dart';
   import 'package:barback/barback.dart';
  
positive.code: ///
  /// Returns the result of evaluating each of the element annotations
  /// in [metadata] using [_getEvaluatedMetadatum].
  Iterable<DartObjectImpl> _getEvaluatedMetadata(
      Iterable<ElementAnnotation> metadata) {
    return metadata.map(_getEvaluatedMetadatum);
  }
  
negative.code:   @override
    void visitChildren(ElementVisitor visitor) =>
        throw unreachableError("visitChildren");
  
    @override
    bool get isAlwaysThrows => throw unreachableError("isAlwaysThrows");
  
    @override
    bool get isVisibleForTesting => throw unreachableError("isVisibleForTesting");
  }
  
  bool _isSetterName(String name) => name.endsWith("=");
  