anchor.diff:    bool isAttached = false;
   
     static const double _kSettleVelocity = 1.5; // dips per ms
  +  static const double _kMinSettleDuration = 200.0; // ms
  +  static const double _kMaxSettleDuration = 500.0; // ms
   
     FcCard.created() : super.created() {
     }
  
positive.code: import "package:polymer/polymer.dart";
  import "dart:async";
  import "dart:html";
  
  import "deck/deck.dart";
  import "viewmodel/viewmodel.dart";
  
negative.code:       if (displacement == null)
          return;
        double distance = displacement.magnitude;
        double duration = min(max(distance / _kSettleVelocity, _kMinSettleDuration), _kMaxSettleDuration);
        classes.add("moving");
        WebAnimations.animate(this, [{
          "transform": "translate(${-displacement.x}px, ${-displacement.y}px)"
  