overlapping transform

[vjyanand]

How do I avoid overlapping when swipe with transform as below?

class DeckTransformer extends PageTransformer {
  @override
  Widget transform(Widget item, TransformInfo info) {
    double position = info.position;
    if (position <= 0) {
      return item;    
    } else if (position <= 1) {
      return Transform.translate(
        offset: Offset(0, -info.height * position),
        child: item,
      );
    }
    return item;
  }
}

TransformerPageView(
   scrollDirection: Axis.horizontal, 
   transformer: DeckTransformer(),

Sorry for posting help request in issue.