anchor.diff:    }
   
     /**
  +   * Return the [Source] for the given [path] in [_sourceFactory].
  +   */
  +  Source _sourceForPath(String path) {
  +    Source fileSource = _resourceProvider.getFile(path).createSource();
  +    Uri uri = _sourceFactory.restoreUri(fileSource);
  +    return _resourceProvider.getFile(path).createSource(uri);
  +  }
  +
  +  /**
      * Verify the API signature for the file with the given [path], and decide
      * which linked libraries should be invalidated, and files reanalyzed.
      *
  
positive.code:         // Analyze a general file.
          if (_filesToAnalyze.isNotEmpty) {
            String path = _removeFirst(_filesToAnalyze);
            _File file = _fileForPath(path);
            AnalysisResult result = _computeAnalysisResult(file, withUnit: false);
            yield result;
            // Repeat the processing loop.
            _hasWork.notify();
  
negative.code:    */
    final CompilationUnit unit;
  
    /**
     * Return the file with consistent [content] and [contentHash].
     */
    factory _File.forContent(AnalysisDriver driver, Source source) {
      String path = source.fullName;
      // Read the content.
      String content;
  