anchor.diff:      if (_variables != null) return _variables;
   
       Set<TopLevelVariableElement> elements = new Set();
  -    elements.addAll(_library.definingCompilationUnit.topLevelVariables);
  -    for (CompilationUnitElement cu in _library.parts) {
  +    elements.addAll(_libraryElement.definingCompilationUnit.topLevelVariables);
  +    for (CompilationUnitElement cu in _libraryElement.parts) {
         elements.addAll(cu.topLevelVariables);
       }
       _exportedNamespace.definedNames.values.forEach((element) {
  
positive.code: 
    String get packageName {
      if (_packageName == null) {
        String sourcePath = _library.source.fullName;
        File file = new File(sourcePath);
        if (file.existsSync()) {
          _packageName = _getPackageName(file.parent);
  
negative.code:     return _classes;
    }
  
    LibraryElement get _libraryElement => (element as LibraryElement);
  
    Class getClassByName(String name) {
      return _allClasses.firstWhere((it) => it.name == name, orElse: () => null);
  