anchor.diff:      }
     }
   
  -  /**
  -   * Remove the file with the given [path] from the list of files to analyze.
  -   *
  -   * The [path] must be absolute and normalized.
  -   *
  -   * The results of analysis of the file might still be produced by the
  -   * [results] stream. The driver will try to stop producing these results,
  -   * but does not guarantee this.
  -   */
  +  /// Remove the file with the given [path] from the list of files to analyze.
  +  ///
  +  /// The [path] must be absolute and normalized.
  +  ///
  +  /// The results of analysis of the file might still be produced by the
  +  /// [results] stream. The driver will try to stop producing these results,
  +  /// but does not guarantee this.
     void removeFile(String path) {
       _throwIfNotAbsolutePath(path);
       _throwIfChangesAreNotAllowed();
  
positive.code:     return completer.future;
    }
  
    /**
     * Return a [Future] that completes with a [ResolvedLibraryResult] for the
     * Dart library file with the given [uri].
     *
     * Throw [ArgumentError] if the given [uri] is not the defining compilation
     * unit for a library (that is, is a part of a library).
     *
     * Invocation of this method causes the analysis state to transition to
     * "analyzing" (if it is not in that state already), the driver will produce
     * the resolution result for it, which is consistent with the current file
     * state (including new states of the files previously reported using
     * [changeFile]), prior to the next time the analysis state transitions
     * to "idle".
     */
    Future<ResolvedLibraryResult> getResolvedLibraryByUri(Uri uri) {
      FileState file = _fsState.getFileForUri(uri);
  
  
negative.code:     _fileTracker.addFiles(addedFiles);
    }
  
    /// Return a [Future] that completes when discovery of all files that are
    /// potentially available is done, so that they are included in [knownFiles].
    Future<void> discoverAvailableFiles() {
      if (_discoverAvailableFilesTask != null &&
          _discoverAvailableFilesTask.isCompleted) {
  