anchor.diff:  
     print('>>> BATCH START');
   
  -  String line;
  -  CompilerResult result;
  +  String? line;
  +  CompilerResult? result;
   
     while ((line = stdin.readLineSync(encoding: utf8))?.isNotEmpty == true) {
       totalTests++;
  -    var args = batchArgs.merge(line.split(RegExp(r'\s+')));
  +    var args = batchArgs.merge(line!.split(RegExp(r'\s+')));
   
       String outcome;
       try {
  
positive.code: ///
  /// [sendPort] may be passed in when started in an isolate. If provided, it is
  /// used for bazel worker communication instead of stdin/stdout.
  Future internalMain(List<String> args, [SendPort sendPort]) async {
    // Always returns a new modifiable list.
    var parsedArgs = ParsedArguments.from(args);
  
  
negative.code:       output.writeln(message.toString());
      }));
      return WorkResponse()
        ..exitCode = lastResult!.success ? 0 : 1
        ..output = output.toString();
    }
  }
  