 
 import spark.components.supportClasses.GroupBase;
 import spark.core.NavigationUnit;
-import spark.core.ScrollUnit;
+import spark.core.NavigationUnit;
 import spark.layouts.supportClasses.LayoutBase;
 import spark.layouts.supportClasses.LayoutElementHelper;
 import spark.layouts.supportClasses.LinearLayoutVector;

    /**
     * @private
     */
    override public function clearCachedVirtualLayoutState():void
    {
        llv.clear();
    }     

    /**
     *  @private 
     */  
     override public function getNavigationDestinationIndex(currentIndex:int, navigationUnit:uint):int
     {
        if (!target || target.numElements < 1)
            return -1; 
