anchor.diff:  
   import 'models.dart';
   import 'resolver.dart' as resolver;
  +
  +final _autoGeneratedImportSource = _AutoGeneratedImportSource();
   
   /// Interface for resolving and getting data for profiles.
   abstract class ImportSource {
  
positive.code: 
    @override
    Future<List<int>> getArchiveBytes(String package, String version) async {
      final archive = ArchiveBuilder();
  
      final isFlutter = package.startsWith('flutter_');
      final pubspec = json.encode({
        'name': package,
        'version': version,
        'environment': {
          'sdk': '>=2.6.0 <3.0.0',
        },
        'dependencies': {
          if (isFlutter) 'flutter': {'sdk': 'flutter'},
        },
      });
      archive.addFile('pubspec.yaml', pubspec);
      archive.addFile('README.md', '# $package\n\nAwesome package.');
      archive.addFile('CHANGELOG.md', '## $version\n\n- updated');
      archive.addFile('lib/$package.dart', 'main() {\n  print(\'Hello.\');\n}\n');
      archive.addFile(
          'example/example.dart', 'main() {\n  print(\'example\');\n}\n');
      archive.addFile('LICENSE', 'All rights reserved.');
      return archive.toTarGzBytes();
    }
  
    @override
  
negative.code: 
    /// Creates a source that generates data based on random seed, without any
    /// network (or file) access.
    static ImportSource autoGenerated() => _autoGeneratedImportSource;
  }
  
  /// Resolves and downloads data from pub.dev.
  