anchor.diff:  
       testUsingContext('Bad ipa zip-file, no payload dir', () {
         globals.fs.file('app.ipa').createSync();
  -      when(os.unzip(globals.fs.file('app.ipa'), any)).thenAnswer((Invocation _) { });
         final PrebuiltIOSApp iosApp = IOSApp.fromPrebuiltApp(globals.fs.file('app.ipa')) as PrebuiltIOSApp;
         expect(iosApp, isNull);
         expect(
  
positive.code: 
      testUsingContext('Bad ipa zip-file, two app bundles', () {
        globals.fs.file('app.ipa').createSync();
        when(os.unzip(any, any)).thenAnswer((Invocation invocation) {
          final File zipFile = invocation.positionalArguments[0] as File;
          if (zipFile.path != 'app.ipa') {
            return;
          }
          final Directory targetDirectory = invocation.positionalArguments[1] as Directory;
          final String bundlePath1 =
              globals.fs.path.join(targetDirectory.path, 'Payload', 'bundle1.app');
          final String bundlePath2 =
              globals.fs.path.join(targetDirectory.path, 'Payload', 'bundle2.app');
          globals.fs.directory(bundlePath1).createSync(recursive: true);
          globals.fs.directory(bundlePath2).createSync(recursive: true);
        });
        final PrebuiltIOSApp iosApp = IOSApp.fromPrebuiltApp(globals.fs.file('app.ipa')) as PrebuiltIOSApp;
        expect(iosApp, isNull);
        expect(testLogger.errorText,
  
negative.code: import 'package:flutter_tools/src/ios/application_package.dart';
  import 'package:flutter_tools/src/ios/plist_parser.dart';
  import 'package:flutter_tools/src/project.dart';
  import 'package:test/fake.dart';
  
  import '../src/common.dart';
  import '../src/context.dart';
  import '../src/fakes.dart';
  
  void main() {
    group('Apk with partial Android SDK works', () {
      FakeAndroidSdk sdk;
      FakeProcessManager fakeProcessManager;
      MemoryFileSystem fs;
      Cache cache;
  