anchor.diff:  
     final String tooltip;
   
  -  final String description;
  -
  -  final String tooltipUrl;
  +  final String? description;
  +
  +  final String? tooltipUrl;
   }
   
   final debugAllowBanner = ToggleableServiceExtensionDescription<bool>._(
  
positive.code:   slowAnimations,
  ].map((extension) => extension.extension).toSet();
  
  bool isUnsafeBeforeFirstFlutterFrame(String extensionName) {
    return _unsafeBeforeFirstFrameFlutterExtensions.contains(extensionName);
  }
  
  
negative.code: 
    final List<String> displayValues;
  
    /// Analytics screen (screen name where item lives).
    final String? gaScreenName;
  
    /// Analytics item name (toggleable item's name).
    final String? gaItem;
  
    String get gaItemTooltipLink => '${gaItem}TooltipLink';
  
  