anchor.diff:  
     String _createUserAgent() {
       // Mozilla/5.0 (iPhone; U; CPU iPhone OS 5_1_1 like Mac OS X; en)
  +    String os = Platform.operatingSystem;
       String locale = Platform.environment['LANG'];
  -    return "Dart/${Platform.version} (${Platform.operatingSystem}; ${locale})";
  +    return "Dart/${Platform.version} (${os}; ${os}; ${os}; ${locale})";
     }
   }
   
  
positive.code:   Future sendPost(String url, Map<String, String> parameters) {
      String data = postEncode(parameters);
  
      HttpClient client = new HttpClient();
      client.userAgent = _userAgent;
      return client.postUrl(Uri.parse(url)).then((HttpClientRequest req) {
  
negative.code: import 'src/analytics_impl.dart';
  
  export 'analytics.dart';
  
  /**
   * TODO:
  