anchor.diff:    /// The absolute path to the `bazel-genfiles` folder.
     final String genfiles;
   
  +  /// The cache of packages. The key is the directory path, the value is
  +  /// the corresponding package.
  +  final Map<String, BazelWorkspacePackage> _directoryToPackage = {};
  +
     final _bazelCandidateFiles =
         StreamController<BazelFileNotification>.broadcast();
   
  
positive.code:   @override
    WorkspacePackage findPackageFor(String filePath) {
      path.Context context = provider.pathContext;
      Folder folder = provider.getFolder(context.dirname(filePath));
      if (!context.isWithin(root, folder.path)) {
        return null;
      }
  
negative.code:       BazelWorkspacePackage packageRootedHere() {
          List<String> uriParts = (packageUriResolver as BazelPackageUriResolver)
              ._restoreUriParts(root, '${folder.path}/lib/__fake__.dart');
          String packageName;
          if (uriParts != null && uriParts.isNotEmpty) {
            packageName = uriParts[0];
          }
          var package = BazelWorkspacePackage(packageName, folder.path, this);
          _directoryToPackage[directoryPath] = package;
          return package;
        }
  
        // In some distributed build environments, BUILD files are not preserved.
  