anchor.diff:  
     scrollToSelectedIfNotVisible() {
   
  -    var _scrollListDiv = ref('round-list');
       var selectedItemOrder = 0;
   
       selectedItemOrder = items.map((e) => e[VALUE]).toList().indexOf(selected.value);
  
positive.code:   get _visibleItemsWindowSize => ref('itemsDiv') != null ? ref('itemsDiv').marginEdge.width : null;
    get _spanWidth => ref('${items[0][VALUE]}') != null ? ref('${items[0][VALUE]}').marginEdge.width : null;
  
    get _shouldDrawRight => ref('round-list').style.marginLeft > getMinMarginLeft();
    get _shouldDrawLeft => ref('round-list').style.marginLeft < 0;
  
    var browserWindow;
  
    static const String VALUE = 'value';
    static const String TEXT = 'text';
  
negative.code:     _scrollStep = _scrollStep.replaceAll('px','');
      _scrollStep = num.parse(_scrollStep).round();
  
      checkSetScrollStepRedraw(_scrollStep);
    }
  
    showFirst() =>
        checkSetScrollStepRedraw(0);
  
    showLast() =>
        checkSetScrollStepRedraw(getMinMarginLeft());
  
    scroll({toLeft: true}) {
      var _itemSpan = ref(items[0][VALUE].toString());
      var _scrollStep = _scrollListDiv.style.marginLeft;
  
      if (_scrollStep == '') {
  