anchor.diff:    final Map<String, dynamic> _json;
     final String _name;
     final String _version;
  +  final String _etag;
   
     final String _shortName;
     final String _gitName;
  
positive.code:           clientVersionBuild = (forceVersion != null) ? forceVersion : int.parse(version.substring(clientVersion.length + 1)) + 1;
          } else {
            if (version.startsWith(clientVersion)) {
              if (etag == _json["etag"]) {
                print("Nothing changed for $_libraryName");
                return false;
              } else {
  
negative.code:     var json = JSON.parse(data);
      String name = json["name"];
      String version = json["version"];
      String etag = json["etag"];
  
      return new Generator.core(json, name, version, prefix, etag);
    }
  
    Generator.core(this._json, String name, String version, this._prefix, this._etag) :
      _name = name,
      _version = version,
      _shortName = cleanName("${name}_${version}").toLowerCase(),
  