anchor.diff:      }
       
       void callbackStart(_) {
  -      if (i == 5) {
  +      if (i == 7) {
           window.requestAnimationFrame(callbackEnd);
           return;
         }
  
positive.code: import "package:dnd/dnd.dart";
  
  void main() {
    var box = boxManager.create(128, 128);
    box.appendTo(document.body);
    box.setColor("blue", background: true);
    box.enableDragging(new Dropzone(document.body));
  
    boxManager.moveApart(20);
    document.onKeyPress.where((it) => it.keyCode == 67).listen((e) {
      var newBox = boxManager.clone(box);
      var e = newBox.element;
      
      int i = 0;
  
negative.code:     
      window.requestAnimationFrame(callbackStart);
    });
    
    document.onKeyPress.where((e) => e.keyCode == 82).listen((e) {
      var boxes = new List.from(boxManager.boxes);
      boxes.forEach((box) {
        if (mainBox != box) {
          boxManager.remove(box);
        }
      });
    });
  }