function makeTree()
        {
            $areas = $this->arr();
            $areaTree = [];
            foreach ($areas as $id=>$area)
            {
                if(isset($areas[$area["pid"]]))
                {
                    $areas[$area["pid"]]["children"][] = &$areas[$id];
                } 
                else 
                {
                    $areaTree[] = &$areas[$id];
                }
            }
            return $areaTree;
        }