anchor.diff:  import 'dart:ui' as ui;
   
   import 'package:flutter/painting.dart';
  +import 'package:flutter/rendering.dart';
   import 'package:flutter/scheduler.dart';
   import 'package:vector_math/vector_math_64.dart';
   
  
positive.code:   String result = JSON.encode({
      'type': '_extensionType',
      'method': method,
      'timeDilation': '${timeDilation}'
    });
    return new Future.value(new ServiceExtensionResponse.result(result));
  }
  
  /// Prints a message to the console, which you can access using the "flutter"
  
negative.code:   if (_extensionsInitialized)
      return;
  
    _extensionsInitialized = true;
  
    assert(() {
      registerExtension('flutter', _flutter);
      // TODO: Expose debugDumpApp().
      // TODO: Expose StatisticsOverlay.
      registerExtension('flutter.debugPaint', _debugPaint);
      registerExtension('flutter.timeDilation', _timeDilation);
  
      // Emit an info level log message; this tells the debugger that the Flutter
      // service extensions are registered.
      log('Flutter initialized', name: 'flutter', level: 800);
  
      return true;
    });
  }
  
  /// Just respond to the request. Clients can use the existence of this call to
  /// know that the debug client is a Flutter app.
  Future<ServiceExtensionResponse> _flutter(String method, Map<String, dynamic> parameters) {
    String result = JSON.encode({ 'type': '_extensionType', 'method': method });
    return new Future<ServiceExtensionResponse>.value(new ServiceExtensionResponse.result(result));
  }
  
  /// Toggle the [debugPaintSizeEnabled] setting.
  Future<ServiceExtensionResponse> _debugPaint(String method, Map<String, dynamic> parameters) {
    if (parameters.containsKey('enabled')) {
      // TODO: This is a work around for a VM bug: sdk/25208 - all params are coerced to strings.
      debugPaintSizeEnabled = parameters['enabled'].toString() == 'true';
  
      // Redraw everything - mark the world as dirty.
      RenderObjectVisitor visitor;
      visitor = (RenderObject child) {
        child.markNeedsPaint();
        child.visitChildren(visitor);
      };
      Renderer.instance.renderView.visitChildren(visitor);
    }
  
    String result = JSON.encode({
  