private static function buildData($data, $options)
{
$config = array_merge(self::$config, $options);
self::$config = $config;
extract($config);
$r = array();
foreach ($data as $item) {
$id = $item[$primary_key];
$parent_id = $item[$parent_key];
$r[$parent_id][$id] = $item;
}
return $r;
}