anchor.diff:        AnalysisOptionsImpl(),
         sourceFactory,
         declaredVariables,
  -      [dartCoreResult.bundle],
  +      [sdkBundle],
         libraryUnitMap,
       );
   
  
positive.code: import 'package:analyzer/src/generated/resolver.dart';
  import 'package:analyzer/src/generated/source.dart';
  import 'package:analyzer/src/generated/type_system.dart';
  import 'package:analyzer/src/summary/summary_sdk.dart';
  import 'package:analyzer/src/summary2/link.dart';
  import 'package:analyzer/src/summary2/linked_bundle_context.dart';
  
negative.code: @reflectiveTest
  class ResynthesizeAst2Test extends ResynthesizeTestStrategyTwoPhase
      with ResynthesizeTestCases {
    /// The shared SDK bundle, computed once and shared among test invocations.
    static LinkedNodeBundle _sdkBundle;
  
    @override
    bool get isAstBasedSummary => true;
  
    LinkedNodeBundle get sdkBundle {
      if (_sdkBundle != null) return _sdkBundle;
  
      var sdkUnitMap = <Source, Map<Source, CompilationUnit>>{};
      for (var sdkLibrary in sdk.sdkLibraries) {
        var source = sourceFactory.resolveUri(null, sdkLibrary.shortName);
        var text = getFile(source.fullName).readAsStringSync();
        var unit = parseText(text);
        sdkUnitMap[source] = _unitsOfLibrary(source, unit);
      }
  
      var sdkLinkResult = link(
        AnalysisOptionsImpl(),
        sourceFactory,
        declaredVariables,
        [],
        sdkUnitMap,
      );
  
      var bytes = sdkLinkResult.bundle.toBuffer();
      return _sdkBundle = LinkedNodeBundle.fromBuffer(bytes);
    }
  
    @override
    Future<LibraryElementImpl> checkLibrary(String text,
        {bool allowErrors = false, bool dumpSummaries = false}) async {
      var source = addTestSource(text);
      var unit = parseText(text, experimentStatus: experimentStatus);
  
  