anchor.diff:      ];
     }
     if (sdk == SdkTagValue.flutter) {
  -    options = [
  -      option(
  +    return <SearchTab>[
  +      searchTab(
           label: 'Android',
           tag: FlutterSdkTag.platformAndroid,
           title: 'Packages compatible with Flutter on the Android platform',
         ),
  -      option(
  +      searchTab(
           label: 'iOS',
           tag: FlutterSdkTag.platformIos,
           title: 'Packages compatible with Flutter on the iOS platform',
         ),
  -      option(
  +      searchTab(
           label: 'Web',
           tag: FlutterSdkTag.platformWeb,
           title: 'Packages compatible with Flutter on the Web platform',
         ),
  -      option(
  +      searchTab(
           label: 'Linux',
           tag: FlutterSdkTag.platformLinux,
           title: 'Packages compatible with Flutter on the Linux platform',
         ),
  -      option(
  +      searchTab(
           label: 'macOS',
           tag: FlutterSdkTag.platformMacos,
           title: 'Packages compatible with Flutter on the macOS platform',
         ),
  -      option(
  +      searchTab(
           label: 'Windows',
           tag: FlutterSdkTag.platformWindows,
           title: 'Packages compatible with Flutter on the Windows platform',
         ),
       ];
     }
  -  return _SubSdkLayout(options: options);
  -}
  -
  -class _SubSdkLayout {
  -  final List<_FilterOption>? options;
  -
  -  _SubSdkLayout({
  -    required this.options,
  -  });
  -
  -  bool get hasOptions => options != null && options!.isNotEmpty;
  -}
  -
  -class _FilterOption {
  -  final String label;
  -  final String tag;
  -  final String title;
  -  final bool isActive;
  -
  -  _FilterOption({
  -    required this.label,
  -    required this.tag,
  -    required this.title,
  -    required this.isActive,
  -  });
  -}
  +  return const <SearchTab>[];
  +}
  
positive.code:   final includeDiscontinued = searchForm.includeDiscontinued ?? false;
    final includeUnlisted = searchForm.includeUnlisted ?? false;
    final nullSafe = searchForm.nullSafe ?? false;
    final subSdkLayout = _calculateLayout(searchForm);
    final hasActiveAdvanced = includeDiscontinued || includeUnlisted || nullSafe;
    final values = {
      'has_active_advanced': hasActiveAdvanced,
      'sdk_tabs_html': renderSdkTabs(searchForm: searchForm),
      'has_subsdk_options': subSdkLayout.hasOptions,
      'subsdk_label': _subSdkLabel(searchForm),
      'subsdk_filter_buttons_html': _renderFilterButtons(
          searchForm: searchForm, options: subSdkLayout.options),
      'is_search': isSearch,
      'listing_info_html': renderListingInfo(
        searchForm: searchForm,
  
negative.code:   }
  }
  
  /// `Linux`, `macOS`, `Windows` platforms are not yet stable, and we want
  /// to display them only when the user has already opted-in to get them
  /// displayed.
  List<SearchTab> _calculateSearchTabs(SearchForm searchForm) {
    SearchTab searchTab({
      required String label,
      required String tag,
      required String title,
    }) {
      final tp = searchForm.tagsPredicate;
      return SearchTab(
        text: label,
        href: searchForm
            .change(
              tagsPredicate: tp.isRequiredTag(tag)
                  ? tp.withoutTag(tag)
                  : tp.appendPredicate(TagsPredicate(requiredTags: [tag])),
            )
            .toSearchLink(),
        title: title,
        active: searchForm.tagsPredicate.isRequiredTag(tag),
      );
    }
  
    final sdk = searchForm.sdk;
    if (sdk == SdkTagValue.dart) {
      return <SearchTab>[
        searchTab(
          label: 'native',
          tag: DartSdkTag.runtimeNativeJit,
          title:
              'Packages compatible with Dart running on a native platform (JIT/AOT)',
        ),
        searchTab(
          label: 'JS',
          tag: DartSdkTag.runtimeWeb,
          title: 'Packages compatible with Dart compiled for the web',
  