code: protected org.apache.lucene.search.Query makeTypeQuery(org.apache.lucene.search.Query query, String targetEntityName) {
        return query;
     }
docs: Enhances the give query with an extra condition to discriminate on entity type. This is a no-op in embedded mode
  but other query engines could use it to discriminate if more types are stored in the same index. To be overridden
  by subclasses as needed.