anchor.diff:  // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
   // for details. All rights reserved. Use of this source code is governed by a
   // BSD-style license that can be found in the LICENSE file.
  -
  -// @dart = 2.9
   
   import 'dart:async';
   import 'dart:collection';
  
positive.code:     var watched = bazelWatchedPathsPerFolder.remove(rootFolder);
      if (watched != null) {
        for (var path in watched.paths) {
          bazelWatcherService.stopWatching(watched.workspace, path);
        }
      }
      driverMap.remove(rootFolder);
    }
  
    void _destroyAnalysisContexts() {
      if (_collection != null) {
        for (var analysisContext in _collection.contexts) {
          _destroyAnalysisContext(analysisContext);
        }
        callbacks.afterContextsDestroyed();
  
negative.code:   /// Return the existing analysis context that should be used to analyze the
    /// given [path], or `null` if the [path] is not analyzed in any of the
    /// created analysis contexts.
    DriverBasedAnalysisContext? getContextFor(String path);
  
    /// Return the [AnalysisDriver] for the "innermost" context whose associated
    /// folder is or contains the given path.  ("innermost" refers to the nesting
  