anchor.diff:    scroll({toLeft: true}) {
       if (_state == READY) {
         _state = transitionWillHappen(toLeft: toLeft) ? SCROLLING : READY;
  -      print("scrolling ! ");
         if (toLeft) {
           _scrollListDiv.style.marginLeft = "0px";
         } else if(_visibleItemsWindowSize < _scrollListWidth) {
  
positive.code:   _moveScrollDivToFirstShown() {
      firstIndex = firstShownIndex - _shownItemCount;
      lastIndex = firstShownIndex + 2*_shownItemCount;
      print("F: $firstIndex, FS: $firstShownIndex, L: $lastIndex");
      _scrollListDiv.style.marginLeft = '${(firstIndex - firstShownIndex)*_spanWidth}px';
      _state = AFTER_ADJUST;
      redraw();
  
negative.code:       div({'className' : _getArrowClass(false), 'onMouseDown' : (ev) => showLast()},'>>');
  
    render() {
      return div({'className': selectorClass}, [
          span({"className": "round-selector-text"}, selectorText),
          showFirstLast ? _renderFastLeftArrow() : div({}),
  