anchor.diff:    String? customDevToolsPath,
   }) async {
     final help = args[argHelp];
  +  final bool version = args[argVersion];
     final bool machineMode = args[argMachine];
     // launchBrowser defaults based on machine-mode if not explicitly supplied.
     final bool launchBrowser =
  
positive.code: const argProfileMemory = 'record-memory-profile';
  const argTryPorts = 'try-ports';
  const argVerbose = 'verbose';
  const launchDevToolsService = 'launchDevTools';
  
  const defaultTryPorts = 10;
  
negative.code:     print('Dart DevTools version ${await _getVersion()}');
      print('');
      _printUsage(verbose);
      return null;
    }
  
    if (version) {
      final versionStr = await _getVersion();
      printOutput(
        'Dart DevTools version $versionStr',
        {
          'version': versionStr,
        },
        machineMode: machineMode,
      );
      return null;
    }
  
  