anchor.diff:    }
   
     void addLibraries(Map<String, LibraryReader> libraries) {
  -    libraryReaders.addAll(libraries);
  +    _libraryReaders.addAll(libraries);
     }
   
     Namespace buildExportNamespace(Uri uri) {
  
positive.code:   final AnalysisContextImpl analysisContext;
    final AnalysisSessionImpl analysisSession;
    final Reference rootReference;
    final Map<String, LibraryReader> libraryReaders = {};
    final _exportsOfLibrary = <String, List<Reference>>{};
  
    bool isApplyingInformativeData = false;
  
  
negative.code:   void removeLibraries(Set<String> uriStrSet) {
      for (var uriStr in uriStrSet) {
        _exportsOfLibrary.remove(uriStr);
        _libraryReaders.remove(uriStr);
        var libraryReference = rootReference.removeChild(uriStr);
        _invalidateLibrary(libraryReference);
      }
  