anchor.diff:    /**
      * The class member names defined by the file.
      */
  -  Set<String> get definedClassMemberNames => _definedClassMemberNames;
  +  Set<String> get definedClassMemberNames {
  +    return _definedClassMemberNames ??=
  +        _driverUnlinkedUnit.definedClassMemberNames.toSet();
  +  }
   
     /**
      * The top-level names defined by the file.
      */
  -  Set<String> get definedTopLevelNames => _definedTopLevelNames;
  +  Set<String> get definedTopLevelNames {
  +    return _definedTopLevelNames ??=
  +        _driverUnlinkedUnit.definedTopLevelNames.toSet();
  +  }
   
     /**
      * Return the set of all directly referenced files - imported, exported or
  
positive.code:     }
  
      // Read the unlinked bundle.
      var driverUnlinkedUnit = new AnalysisDriverUnlinkedUnit.fromBuffer(bytes);
      _definedTopLevelNames = driverUnlinkedUnit.definedTopLevelNames.toSet();
      _definedClassMemberNames =
          driverUnlinkedUnit.definedClassMemberNames.toSet();
      _referencedNames = driverUnlinkedUnit.referencedNames.toSet();
      _subtypedNames = driverUnlinkedUnit.subtypedNames.toSet();
      _unlinked = driverUnlinkedUnit.unit;
      _lineInfo = new LineInfo(_unlinked.lineStarts);
      _topLevelDeclarations = null;
  
      // Prepare API signature.
  
negative.code:   String _content;
    String _contentHash;
    LineInfo _lineInfo;
    Set<String> _definedClassMemberNames;
    Set<String> _definedTopLevelNames;
    Set<String> _referencedNames;
    Set<String> _subtypedNames;
    String _unlinkedKey;
    AnalysisDriverUnlinkedUnit _driverUnlinkedUnit;
    UnlinkedUnit _unlinked;
    List<int> _apiSignature;
  
  