anchor.diff:      expect(tester.binding.hasScheduledFrame, isFalse);
   
       int frameCount = 0;
  -    tester.binding.addPostFrameCallback((Duration duration) { frameCount += 1; });
  +    tester.binding.addPostFrameCallback((Duration duration) {
  +      frameCount += 1;
  +    });
       expect(tester.binding.hasScheduledFrame, isFalse);
       await tester.pump(const Duration(milliseconds: 1));
       expect(tester.binding.hasScheduledFrame, isFalse);
  
positive.code:     final ByteData message = const JSONMethodCodec().encodeMethodCall(
        const MethodCall('pushRouteInformation', testRouteInformation),
      );
      await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
      expect(observer.pushedRoute, 'testRouteName');
      WidgetsBinding.instance!.removeObserver(observer);
    });
  
negative.code:     expect(frameCount, 1);
  
      // Get the tester back to a resumed state for subsequent tests.
      setAppLifeCycleState(AppLifecycleState.resumed);
      expect(tester.binding.hasScheduledFrame, isTrue);
      await tester.pump();
    });
  