protected function page()
    {
        if ($this->key() == $this->count() || !$this->isScrollable()) {
            return $this;
        }

//        $raw = $this->manager->scroll($this->scrollId, $this->scrollDuration, Result::RESULTS_RAW);
        $raw = $this->manager->getClient()->scroll(
            [
                'scroll' => $this->scrollDuration,
                'scroll_id' => $this->scrollId,
            ]
        );
        $this->rewind();
        $this->scrollId = $raw['_scroll_id'];
        $this->documents = $raw['hits']['hits'];

        return $this;
    }