anchor.diff:        }
   
         final packages =
  -          ((await _getJson('https://pub.dev/api/package-names'))['packages']
  +          ((await getJson('https://pub.dev/api/package-names'))['packages']
                     as List)
                 .cast<String>();
         print('Found ${packages.length} packages to scan');
  
positive.code:       await Future.wait(packages.map((package) async {
          await pool.withResource(() async {
            final versionsResponse =
                await _getJson('https://pub.dev/api/packages/$package');
            final archiveUrl = Uri.tryParse(
              versionsResponse['latest']?['archive_url'] as String? ?? '',
            );
  
negative.code:     'crash test',
      () async {
        final c = http.RetryClient(http.Client());
        Future<dynamic> getJson(String url) async {
          final u = Uri.tryParse(url);
          if (u == null) {
            return null;
  