public function loadQueueItems()
    {
        $loader = new CollectionLoader([
            'logger'  => $this->logger,
            'factory' => $this->queueItemFactory(),
        ]);
        $loader->setModel($this->queueItemProto());
        $loader->addFilter([
            'property' => 'processed',
            'value'    => 0,
        ]);
        $loader->addFilter([
             'property' => 'processing_date',
             'operator' => '<',
             'value'    => date('Y-m-d H:i:s'),
        ]);

        $queueId = $this->queueId();
        if ($queueId) {
            $loader->addFilter([
                'property' => 'queue_id',
                'value'    => $queueId,
            ]);
        }

        $loader->addOrder([
            'property' => 'queued_date',
            'mode'     => 'asc',
        ]);

        if ($this->limit > 0) {
            $loader->setNumPerPage($this->limit);
            $loader->setPage(0);
        }

        $queued = $loader->load();

        return $queued;
    }