anchor.diff:    /**
      * The current file state.
      *
  -   * It maps file paths to MD5 hash of the file content.
  +   * It maps file paths to the MD5 hash of the file content.
      */
     final _fileContentHashMap = <String, String>{};
  +
  +  /**
  +   * Mapping from library URIs to the linked hash of the library.
  +   */
  +  final _linkedHashMap = <Uri, String>{};
   
     /**
      * TODO(scheglov) document and improve
  
positive.code:    * TODO(scheglov) replace with actual [AnalysisResult] computing.
     */
    List<String> _computeAndPrintErrors(_File file) {
      List<String> errorStrings = _logger.run('Compute errors $file', () {
        LibraryContext libraryContext = _createLibraryContext(file);
  
  
negative.code:   void changeFile(String path) {
      // TODO(scheglov) Don't clear, schedule API signature validation.
      _fileContentHashMap.clear();
      _linkedHashMap.clear();
      _filesToAnalyze.add(path);
      _filesToAnalyze.addAll(_explicitFiles);
      // TODO(scheglov) name?!
  