code: DocumentExtractor get(UUID queryId) {
        DocumentExtractor extractor = queries.get(queryId);
        if (extractor == null) {
           throw new IllegalStateException("Query not found: " + queryId);
        }
        return extractor;
     }
docs: Get the query (DocumentExtractor) by id..
  
  @param queryId The id of the query
  @return the DocumentExtractor