anchor.diff:              child: new CustomScrollView(
                 slivers: <Widget>[
                   new CupertinoRefreshControl(
  -                  builder: mockHelper.builder,
  +                  builder: builder,
                   ),
                   buildAListOfStuff(),
                 ],
  
positive.code:           child: new CustomScrollView(
              slivers: <Widget>[
                new CupertinoRefreshControl(
                  builder: mockHelper.builder,
                  refreshTriggerPullDistance: 80.0,
                ),
                buildAListOfStuff(),
  
negative.code:             child: new CustomScrollView(
                slivers: <Widget>[
                  new CupertinoRefreshControl(
                    builder: builder,
                    onRefresh: onRefresh,
                    refreshTriggerPullDistance: 90.0,
                    refreshIndicatorExtent: 50.0,
                  ),
  