anchor.diff:    void changeFile(String path) {
       _filesToVerifyUnlinkedSignature.add(path);
       _filesToAnalyze.add(path);
  -    _hasWorkStreamController.add('do it!');
  +    _hasWork.notify();
     }
   
     /**
  
positive.code: }
  
  /**
   * TODO(scheglov) document
   */
  class _ReferencedUris {
  
negative.code:   void addFile(String path) {
      _explicitFiles.add(path);
      _filesToAnalyze.add(path);
      _hasWork.notify();
    }
  
    /**
  