Following the merge of [high-level field retrieval in _search](https://github.com/elastic/elasticsearch/pull/60100) (docs [here](https://www.elastic.co/guide/en/elasticsearch/reference/7.11/search-fields.html#search-fields-param)), we should switch from extraction from `_source` and `docvalue_fields` to using `fields` option.
Following the merge of high-level field retrieval in _search (docs here), we should switch from extraction from
_sourceanddocvalue_fieldsto usingfieldsoption.