/** * @return Z_Acl */ public static function getInstance() { if (null === self::$_instance) { $cache = Z_Cache::getInstance(); if (!($acl = $cache->load('z_acl'))) { $acl = new Z_Acl(); $cache->save($acl, 'z_acl'); } self::$_instance = $acl; } return self::$_instance; }