anchor.diff:      var unit = parseText(text, featureSet);
   
       var units = <LinkInputUnit>[];
  -    _addLibraryUnits(source, unit, units);
  +    _addLibraryUnits(source, unit, units, featureSet);
       libraries.add(
         LinkInputLibrary(source, units),
       );
  
positive.code:     Source definingSource,
      CompilationUnit definingUnit,
      List<LinkInputUnit> units,
    ) {
      units.add(
        LinkInputUnit(null, definingSource, false, definingUnit),
  
negative.code:       var unit = parseText(text, featureSet);
  
        var inputUnits = <LinkInputUnit>[];
        _addLibraryUnits(source, unit, inputUnits, featureSet);
        inputLibraries.add(
          LinkInputLibrary(source, inputUnits),
        );
  