searchWithScroll

async function searchWithScroll(indexName, pageSize, query, maxResults) {
	let scrollId;
	let results = [];
	let _query = Object.keys(query).length === 0 ? {
		query: {
			"match_all": {}
		}
	} : {
		query: query
	};
	while (true) {
		const response = scrollId ?
			await client.scroll({
				scroll_id: scrollId,
				scroll: '1m',
			}) :
			await client.search({
				index: indexName,
				size: pageSize,
				scroll: '1m',
				body: _query,
				sort: [
					{
						"_fieldsCount": {
							"order": "desc"
						}
					}
				]
			});

		const hits = response.hits.hits;
		scrollId = response._scroll_id;

		if (!hits.length || results.length >= maxResults) break;

		results = results.concat(hits.slice(0, maxResults - results.length));

		return true;
	}

	// Clear the scroll to free resources in Elasticsearch
	await client.clearScroll({
		scroll_id: scrollId
	});
	results = results.map(t => cleanLead(t._source, true));
	return results;
}