if (source != null) {
                        docMap.putAll(source);
                    }
                    final Map<String, DocumentField> fields = hit.getFields();
                    if (fields != null) {
                        docMap.putAll(fields.entrySet()
                                .stream()
                                .collect(Collectors.toMap(Entry::getKey, e -> (Object) e.getValue().getValues())));