anchor.diff:      return package;
     }
   
  -  String toString() => '$name @ $path';
  +  String toString() => '$name @ $version';
   
     int compareTo(VizPackage other) {
       return name.compareTo(other.name);
  
positive.code:     if (other is VizPackage) {
        var match = (name == other.name);
        if (match) {
          assert(other.path == path);
          assert(other.version == version);
          return true;
        }
  
negative.code: 
    Version get latestVersion => _latestVersion;
  
    VizPackage._(this.name, this.version, Set<Dependency> deps)
        : dependencies = new UnmodifiableSetView(deps);
  
    static Future<VizPackage> forDirectory(String path,
        {bool flagOutdated: false}) async {
  