anchor.diff:        'flutter_framework_uncompressed_bytes': await flutterFramework.length(),
       };
     }
  -
   
     static Future<Map<String, dynamic>> getSizesFromApk(String apkPath) async {
       final  String output = await eval('unzip', <String>['-v', apkPath]);
  
positive.code:       await flutter('packages', options: <String>['get']);
  
        final Map<String, dynamic> metrics = <String, dynamic>{
          ...await _compileAot(),
          ...await _compileApp(reportPackageContentSizes: reportPackageContentSizes),
          ...await _compileDebug(),
        };
  
        return TaskResult.success(metrics, benchmarkScoreKeys: metrics.keys.toList());
      });
    }
  
    static Future<Map<String, dynamic>> _compileAot() async {
      await flutter('clean');
      final Stopwatch watch = Stopwatch()..start();
      final List<String> options = <String>[
        'aot',
        '-v',
        '--extra-gen-snapshot-options=--print_snapshot_sizes',
        '--release',
        '--no-pub',
        '--target-platform',
      ];
      switch (deviceOperatingSystem) {
        case DeviceOperatingSystem.ios:
          options.add('ios');
          break;
        case DeviceOperatingSystem.android:
          options.add('android-arm');
          break;
        case DeviceOperatingSystem.fuchsia:
          throw Exception('Unsupported option for Fuchsia devices');
      }
      final String compileLog = await evalFlutter('build', options: options);
      watch.stop();
  
      final RegExp metricExpression = RegExp(r'([a-zA-Z]+)\(CodeSize\)\: (\d+)');
      final Map<String, dynamic> metrics = <String, dynamic>{};
      for (final Match m in metricExpression.allMatches(compileLog)) {
        metrics[_sdkNameToMetricName(m.group(1))] = int.parse(m.group(2));
      }
      if (metrics.length != _kSdkNameToMetricNameMapping.length) {
        throw 'Expected metrics: ${_kSdkNameToMetricNameMapping.keys}, but got: ${metrics.keys}.';
      }
      metrics['aot_snapshot_compile_millis'] = watch.elapsedMilliseconds;
  
      return metrics;
    }
  
    static Future<Map<String, dynamic>> _compileApp({ bool reportPackageContentSizes = false }) async {
  
negative.code:     };
    }
  
    static Future<Map<String, dynamic>> getSizesFromIosApp(String appPath) async {
      // Thin the binary to only contain one architecture.
      final String xcodeBackend = path.join(flutterDirectory.path, 'packages', 'flutter_tools', 'bin', 'xcode_backend.sh');
  