code: function refreshScrollbarAppearance(isHorizontal, shallBeVisible, canScroll) {
                      var scrollbarClassName = isHorizontal ? _classNameHostScrollbarHorizontalHidden : _classNameHostScrollbarVerticalHidden;
                      var scrollbarElement = isHorizontal ? _scrollbarHorizontalElement : _scrollbarVerticalElement;
  
                      if (shallBeVisible)
                          removeClass(_hostElement, scrollbarClassName);
                      else
                          addClass(_hostElement, scrollbarClassName);
  
                      if (canScroll)
                          removeClass(scrollbarElement, _classNameScrollbarUnusable);
                      else
                          addClass(scrollbarElement, _classNameScrollbarUnusable);
                  }
docs: Shows or hides the given scrollbar and applied a class name which indicates if the scrollbar is scrollable or not.
  @param isHorizontal True if the horizontal scrollbar is the target, false if the vertical scrollbar is the target.
  @param shallBeVisible True if the scrollbar shall be shown, false if hidden.
  @param canScroll True if the scrollbar is scrollable, false otherwise.