title: Only return specific fields in elastic search native query Java api
body: <p>I'm building a native query but I only want to return certain fields, all of which are held within a parent field. I think I am looking for the QueryBuilders or NativeSearchQueryBuilder equivalent of the REST API's _source. Here's a code example:</p>
  
  <pre><code>NativeSearchQueryBuilder sb = new NativeSearchQueryBuilder()
  .withIndices("myIndex")
  .withTypes("myType")
  .withQuery(QueryBuilders.queryStringQuery("parent.field2:Foo*"));
  .withFields("parent.field1");
  </code></pre>
  
  <p>I'd expect this to return a list of only parent.field1 that are associated with objects that have parent.field2 like Foo*. But it returns nothing.</p>
  
  <p>Thanks for any help! </p>