anchor.diff:    @override
     Future<bool> isAppInstalled(ApplicationPackage app) async {
       try {
  -      final RunResult apps = await runCheckedAsync(<String>[installerPath, '--list-apps']);
  +      final RunResult apps = await runCheckedAsync(<String>[_installerPath, '--list-apps']);
         if (new RegExp(app.id, multiLine: true).hasMatch(apps.stdout)) {
           return true;
         }
  
positive.code:   }
  
    @override
    bool get supportsScreenshot => screenshotPath != null && screenshotPath.isNotEmpty;
  
    @override
    Future<Null> takeScreenshot(File outputFile) {
      return runCheckedAsync(<String>[screenshotPath, outputFile.path]);
    }
  }
  
  
negative.code:     }
  
      try {
        await runCheckedAsync(<String>[_installerPath, '-i', iosApp.deviceBundlePath]);
        return true;
      } catch (e) {
        return false;
  