anchor.diff:      DartdocOptionArgOnly<bool>('useCategories', true,
           help: 'Display categories in the sidebar of packages'),
       DartdocOptionArgOnly<bool>('validateLinks', true,
  -        help:
  -            'Runs the built-in link checker to display Dart context aware warnings for broken links (slow)',
  +        help: 'Runs the built-in link checker to display Dart context aware '
  +            'warnings for broken links (slow)',
           negatable: true),
       DartdocOptionArgOnly<bool>('verboseWarnings', true,
           help: 'Display extra debugging information and help with warnings.',
  
positive.code:   Future<Tuple2<String, Function()>> modifyArgsToCreateSnapshotIfNeeded(
        List<String> args) async {
      assert(args[0] == command.first);
      // Set up flags to create a new snapshot, if needed, and use the first run as the training
      // run.
      var snapshot = SnapshotCache.instance.getSnapshot(command.first);
      var snapshotFile = snapshot.snapshotFile;
      var needsSnapshot = snapshot.needsSnapshot;
  
negative.code:   p.Context pathContext;
  
    /// Build a _OptionValueWithContext.
    ///
    /// [path] is the path where this value came from (not required to be
    /// canonical).
    _OptionValueWithContext(this.value, String path, {String definingFile}) {
      this.definingFile = definingFile;
      canonicalDirectoryPath = p.canonicalize(path);
      pathContext = p.Context(current: canonicalDirectoryPath);
    }
  
    /// Assume value is a path, and attempt to resolve it.
    ///
    /// Throws [UnsupportedError] if [T] isn't a [String] or [List<String>].
    T get resolvedValue {
      if (value is List<String>) {
        return (value as List<String>)
  