anchor.diff:  
       expect(completer.debugLabel, url);
     });
  -
  -}
  -
  -class _MockHttpClient extends Mock implements HttpClient {}
  -class _MockHttpClientRequest extends Mock implements HttpClientRequest {}
  -class _MockHttpClientResponse extends Mock implements HttpClientResponse {}
  +}
  +
  +class _FakeHttpClient extends Fake implements HttpClient {
  +  final _FakeHttpClientRequest request = _FakeHttpClientRequest();
  +  dynamic thrownError;
  +
  +  @override
  +  Future<HttpClientRequest> getUrl(Uri url) async {
  +    if (thrownError != null) {
  +      throw thrownError;
  +    }
  +    return request;
  +  }
  +}
  +class _FakeHttpClientRequest extends Fake implements HttpClientRequest {
  +  final _FakeHttpClientResponse response = _FakeHttpClientResponse();
  +
  +  @override
  +  Future<HttpClientResponse> close() async {
  +    return response;
  +  }
  +}
  +
  +class _FakeHttpClientResponse extends Fake implements HttpClientResponse {
  +  @override
  +  int statusCode = HttpStatus.ok;
  +
  +  @override
  +  int contentLength = 0;
  +
  +  @override
  +  HttpClientResponseCompressionState get compressionState => HttpClientResponseCompressionState.notCompressed;
  +
  +  List<List<int>> content;
  +
  +  @override
  +  StreamSubscription<List<int>> listen(void Function(List<int> event) onData, {Function onError, void Function() onDone, bool cancelOnError}) {
  +    return Stream<List<int>>.fromIterable(content).listen(
  +      onData,
  +      onDone: onDone,
  +      onError: onError,
  +      cancelOnError: cancelOnError,
  +    );
  +  }
  +}
   
   class FakeCodec implements Codec {
     @override
  
positive.code:     return PaintingBinding.instance.instantiateImageCodec(bytes, cacheWidth: cacheWidth, cacheHeight: cacheHeight, allowUpscaling: allowUpscaling);
    };
  
    _MockHttpClient httpClient;
  
    setUp(() {
      httpClient = _MockHttpClient();
      debugNetworkImageHttpClientProvider = () => httpClient;
    });
  
  
negative.code: import 'package:flutter/foundation.dart';
  import 'package:flutter/painting.dart';
  import 'package:flutter_test/flutter_test.dart';
  
  import '../flutter_test_alternative.dart' show Fake;
  import '../rendering/rendering_tester.dart';
  import 'image_data.dart';
  
  