anchor.diff:            flutterVersion.toString(),
             'Flutter • channel $channel • unknown source\n'
             'Framework • revision 1234abcd (1 second ago) • ${getChannelUpToDateVersion()}\n'
  -          'Engine • revision \n'
  -          'Tools • Dart null',
  +          'Engine • revision abcdefg\n'
  +          'Tools • Dart 2.12.0',
           );
           expect(flutterVersion.frameworkAge, '1 second ago');
           expect(flutterVersion.getVersionString(), '$channel/1234abcd');
  
positive.code:       testWithoutContext('pings server when version stamp is missing', () async {
          final FakeFlutterVersion flutterVersion = FakeFlutterVersion(channel);
          final BufferLogger logger = BufferLogger.test();
          when(mockCache.getStampFor(VersionCheckStamp.flutterVersionCheckStampFile))
            .thenReturn('{}');
  
          await checkVersionFreshness(
            flutterVersion,
            cache: mockCache,
            clock: _testClock,
            logger: logger,
            localFrameworkCommitDate: getChannelOutOfDateVersion(),
  
negative.code:       testWithoutContext('does not print warning when unable to connect to server if not out of date', () async {
          final FakeFlutterVersion flutterVersion = FakeFlutterVersion(channel);
          final BufferLogger logger = BufferLogger.test();
          cache.versionStamp = '{}';
  
          await checkVersionFreshness(
            flutterVersion,
            cache: cache,
            clock: _testClock,
            logger: logger,
            localFrameworkCommitDate: getChannelUpToDateVersion(),
  