anchor.diff:  class ResynthesizeAst2Test extends AbstractResynthesizeTest
       with ResynthesizeTestCases {
     /// The shared SDK bundle, computed once and shared among test invocations.
  -  static _SdkBundle _sdkBundleNullSafe;
  -
  -  /// The shared SDK bundle, computed once and shared among test invocations.
  -  static _SdkBundle _sdkBundleLegacy;
  +  static _SdkBundle _sdkBundle;
   
     _SdkBundle get sdkBundle {
  -    if (featureSet.isEnabled(Feature.non_nullable)) {
  -      if (_sdkBundleNullSafe != null) {
  -        return _sdkBundleNullSafe;
  -      }
  -    } else {
  -      if (_sdkBundleLegacy != null) {
  -        return _sdkBundleLegacy;
  -      }
  -    }
  -
  +    if (_sdkBundle != null) {
  +      return _sdkBundle;
  +    }
  +
  +    var featureSet = FeatureSet.latestLanguageVersion();
       var inputLibraries = <LinkInputLibrary>[];
       for (var sdkLibrary in sdk.sdkLibraries) {
         var source = sourceFactory.resolveUri(null, sdkLibrary.shortName);
  
positive.code:     var unit = parseText(text, featureSet);
  
      var units = <LinkInputUnit>[];
      _addLibraryUnits(source, unit, units);
      libraries.add(
        LinkInputLibrary(source, units),
      );
  
negative.code: 
      var sdkLinkResult = link(elementFactory, inputLibraries, true);
  
      return _sdkBundle = _SdkBundle(
        astBytes: sdkLinkResult.astBytes,
        resolutionBytes: sdkLinkResult.resolutionBytes,
      );
    }
  
    @override
  