protected function _getUrlListRecursive($items, $parent, $indent = 0)
{
$parent = (int) $parent;
$resultArray = [];
if (isset($items[$parent]) && $items[$parent]) {
foreach ($items[$parent] as $item) {
$resultArray = $resultArray + [$item->{$this->urlAttribute} => str_repeat('-- ', $indent) . $item->{$this->titleAttribute}] + $this->_getUrlListRecursive($items, $item->getPrimaryKey(), $indent + 1);
}
}
return $resultArray;
}