final Map<String, Object> contentMap = response.getContent(OpenSearchCurl.jsonParser());
                    if (logger.isDebugEnabled()) {
                        logger.debug("[getParentGroup] Response for id {}: {}", id, contentMap);
                    }
                    if (contentMap.containsKey("value")) {
                        final String[] values = DocumentUtil.getValue(contentMap, "value", String[].class);

During crawling and indexing, Fess:

1. Detects language from document content using Apache Tika
2. Validates against `supported.languages` list
3. Creates language-specific fields (e.g., `content_ja`, `title_en`, `content_sv`)
4. Applies language-specific analyzers for better search results

Configured in `fess_config.properties`:
```properties
indexer.language.fields=content,important_content,title
```