public function concat($optionArray = [])
{
$optionArray = array_merge(self::$_optionArray, $optionArray);
$loader = new Assetic\Loader(Registry::getInstance());
$loader->init(self::$_collectionArray[self::$_namespace])->concat($optionArray, self::$_rewriteArray[self::$_namespace]);
/* update collection */
self::$_rewriteArray[self::$_namespace] = [];
self::$_collectionArray[self::$_namespace] = $loader->getCollectionArray();
return $this;
}