anchor.diff:  
       ui.window.onPointerDataPacket(packet1);
   
  -    expect(enter.length, equals(1), reason: 'enter contains $enter');
  -    expect(enter.first.position, equals(const Offset(0.0, 0.0)));
  -    expect(enter.first.device, equals(0));
  -    expect(enter.first.runtimeType, equals(PointerEnterEvent));
  -    expect(move.length, equals(2), reason: 'move contains $move');
  -    expect(move.first.position, equals(const Offset(0.0, 0.0)));
  -    expect(move.first.device, equals(0));
  -    expect(move.first.runtimeType, equals(PointerHoverEvent));
  -    expect(move.last.position, equals(const Offset(1.0, 101.0)));
  -    expect(move.last.device, equals(0));
  -    expect(move.last.runtimeType, equals(PointerHoverEvent));
  -    expect(exit.length, equals(0), reason: 'exit contains $exit');
  +    expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
  +      const PointerEnterEvent(position: Offset(0.0, 0.0)),
  +      const PointerHoverEvent(position: Offset(0.0, 0.0)),
  +      const PointerHoverEvent(position: Offset(1.0, 101.0)),
  +    ]));
       // Simulate layer going away by detaching it.
       clear();
       isInHitRegionOne = false;
   
       ui.window.onPointerDataPacket(packet2);
  -    expect(enter.length, equals(0), reason: 'enter contains $enter');
  -    expect(move.length, equals(0), reason: 'enter contains $move');
  -    expect(exit.length, equals(1), reason: 'enter contains $exit');
  -    expect(exit.first.position, const Offset(1.0, 201.0));
  -    expect(exit.first.device, equals(0));
  -    expect(exit.first.runtimeType, equals(PointerExitEvent));
  +    expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
  +      const PointerExitEvent(position: Offset(1.0, 201.0)),
  +    ]));
   
       // Actually detach annotation. Shouldn't receive hit.
       RendererBinding.instance.mouseTracker.detachAnnotation(annotation);
  
positive.code:     isInHitRegionOne = false;
  
      ui.window.onPointerDataPacket(packet2);
      expect(enter.length, equals(0), reason: 'enter contains $enter');
      expect(move.length, equals(0), reason: 'enter contains $move');
      expect(exit.length, equals(0), reason: 'enter contains $exit');
    });
  
    test("don't flip out if not all mouse events are listened to", () {
      final ui.PointerDataPacket packet = ui.PointerDataPacket(data: <ui.PointerData>[
        ui.PointerData(
          change: ui.PointerChange.hover,
          physicalX: 1.0 * ui.window.devicePixelRatio,
          physicalY: 101.0 * ui.window.devicePixelRatio,
          kind: PointerDeviceKind.mouse,
        ),
      ]);
  
      isInHitRegionOne = false;
  
negative.code: // found in the LICENSE file.
  
  import 'dart:ui' as ui;
  import 'dart:ui' show PointerChange;
  
  import 'package:flutter/cupertino.dart';
  import 'package:flutter/foundation.dart';
  