async scrollSpecifications(request) {
    const ttl = request.getString("scroll", this.defaultScrollTTL),
      id = request.getString("scrollId");

    return global.kuzzle.internalIndex
      .scroll(id, ttl)
      .then(({ scrollId, hits, total }) => ({
        hits,
        scrollId,
        total,
      }));
  }
Scroll over a paginated search results

@param {Request} request
@returns {Promise.<object>}