private function _isDuplicateStylesheet ($path) {
		$result = '';
		$currentRecords = self::$linksGroupContainer[$this->getCtrlActionKey()];
		foreach ($currentRecords as $groupName => $groupItems) {
			foreach ($groupItems as $item) {
				if ($item->path == $path) {
					$result = $groupName;
					break;
				}
			}
		}
		return $result;
	}