anchor.diff:            child: CustomScrollView(
               slivers: <Widget>[
                 CupertinoSliverRefreshControl(
  -                builder: builder,
  -                onRefresh: onRefresh,
  +                builder: mockHelper.builder,
  +                onRefresh: mockHelper.refreshTask,
                 ),
                 buildAListOfStuff(),
               ],
  
positive.code:             child: CustomScrollView(
                slivers: <Widget>[
                  CupertinoSliverRefreshControl(
                    builder: builder,
                    onRefresh: onRefresh,
                  ),
                  buildAListOfStuff(),
                ],
  
negative.code:             child: CustomScrollView(
                slivers: <Widget>[
                  CupertinoSliverRefreshControl(
                    builder: mockHelper.builder,
                    onRefresh: mockHelper.refreshTask,
                  ),
                  buildAListOfStuff(),
                ],
  