anchor.diff:        expect(observatoryContent, startsWith('<!DOCTYPE html>'));
   
         // Check that DevTools assets are accessible.
  -      final devtoolsRequest = await client.getUrl(dds.devToolsUri);
  +      final devtoolsRequest = await client.getUrl(dds!.devToolsUri!);
         final devtoolsResponse = await devtoolsRequest.close();
         expect(devtoolsResponse.statusCode, 200);
         final devtoolsContent =
  
positive.code:     process = null;
    });
  
    defineTest({bool authCodesEnabled}) {
      test(
          'Ensure Observatory and DevTools assets are available with '
          '${authCodesEnabled ? '' : 'no'} auth codes', () async {
  
negative.code:           customBuildDirectoryPath: devtoolsAppUri(prefix: '../../../'),
          ),
        );
        expect(dds!.isRunning, true);
  
        final client = HttpClient();
  
        // Check that Observatory assets are accessible.
        final observatoryRequest = await client.getUrl(dds!.uri!);
        final observatoryResponse = await observatoryRequest.close();
        expect(observatoryResponse.statusCode, 200);
        final observatoryContent =
  