public function trigger($event, $object)
    {
        if ($this->_corked) {
            $this->_queue []= func_get_args();
        } else {
            foreach ((array) $event as $e) {
                $callbacks = $this->_callbacksFor($e);

                foreach($callbacks as $callback)
                    call_user_func($callback, $e, $object);
            }

            if(isset($this->_upstream))
                $this->_upstream->trigger($event, $object);
        }

        return $this;
    }