anchor.diff:            title: title,
           );
   
  -  OverlayEntry _overlayEntry;
  +  late OverlayEntry _overlayEntry;
   
     bool _isRemoved = false;
   
  
positive.code: /// A hover card based tooltip.
  class HoverCardTooltip extends StatefulWidget {
    const HoverCardTooltip({
      @required this.enabled,
      @required this.onHover,
      @required this.child,
      this.disposable,
    });
  
  
negative.code: // Copyright 2021 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  import 'dart:async';
  import 'dart:math' as math;
  