anchor.diff:     * Buffer containing strings printed by the analysis server.
      */
     List<String> _printBuffer;
  +
  +  /**
  +   * Contents of overlay files.
  +   */
  +  final Map<int, String> _overlayContents = <int, String>{};
   
     /**
      * Initialize a newly created handler for GET requests.
  
positive.code:     response.close();
    }
  
    /**
     * Return a response displaying overlays information.
     */
  
negative.code:       _returnCacheEntry(request);
      } else if (path == COMPLETION_PATH) {
        _returnCompletionInfo(request);
      } else if (path == OVERLAY_PATH) {
        _returnOverlayContents(request);
      } else if (path == OVERLAYS_PATH) {
        _returnOverlaysInfo(request);
      } else {
  