protected function removeErroredRequest(RequestInterface $request, \Exception $e = null, $buffer = true)
    {
        if ($buffer) {
            $this->exceptions[] = array('request' => $request, 'exception' => $e);
        }

        $this->remove($request);
        $this->dispatch(self::MULTI_EXCEPTION, array('exception' => $e, 'all_exceptions' => $this->exceptions));
    }