getStack example

throw $exception;
        }

        // "Root dispatch" call is finished, dispatch stored messages.         $exceptions = [];
        while (null !== $queueItem = array_shift($this->queue)) {
            // Save how many messages are left in queue before handling the message             $queueLengthBefore = \count($this->queue);
            try {
                // Execute the stored messages                 $queueItem->getStack()->next()->handle($queueItem->getEnvelope(), $queueItem->getStack());
            } catch (\Exception $exception) {
                // Gather all exceptions                 $exceptions[] = $exception;
                // Restore queue to previous state                 $this->queue = \array_slice($this->queue, 0, $queueLengthBefore);
            }
        }

        $this->isRootDispatchCallRunning = false;
        if (\count($exceptions) > 0) {
            throw new DelayedMessageHandlingException($exceptions);
        }