Convert Lucene BooleanQuery to ES BoolQueryBuilder

Hello,

I'm porting some indices from lucene to ES.
I've managed to use

QueryBuilders.queryStringQuery(queryString);

to parse old lucene string queries to elastic.
However I can't seem to find a way to use Lucene's BooleanQuery with Elastic's BooleanQueryBuilder.

SearchRequest searchRequest = new SearchRequest(INDEX_NAME); SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder(); BoolQueryBuilder mainQuery = new BoolQueryBuilder();

QueryStringQueryBuilder stringQueryBuilder = QueryBuilders.queryStringQuery(queryString); mainQuery.must(stringQueryBuilder);
mainQuery.must( lucene BooleanQuery here) ; searchSourceBuilder.query(mainQuery); searchRequest.source(searchSourceBuilder);

Could this be achieved or am I better off rewriting the code which builds the Lucene BooleanQuery using Elastic Search BooleanQueryBuilder?

Thank you for your time
Mladen