anchor.diff:  
       _onlyDev = value;
     }
  +
  +  Version _latestVersion;
  +
  +  Version get latestVersion => _latestVersion;
   
     VizPackage._(String path, this.name, this.version, Set<Dependency> deps)
         : dependencies = new UnmodifiableSetView(deps),
  
positive.code: import 'package:yaml/yaml.dart' as yaml;
  
  import 'dependency.dart';
  
  class VizPackage extends Comparable {
    final String path;
  
negative.code:       }
      }
    }
  
    Future<Version> updateLatestVersion() async {
      if (_latestVersion != null) return _latestVersion;
  
      _latestVersion = await getLatestVersion(name);
  
      return _latestVersion;
    }
  }
  
  void _writeNode(StringSink sink, String name, Map<String, String> values) {
  