* @param fields Array of field names to include in the result
     * @param userBean Optional user information for permission checking
     * @return Optional entity containing the document data if found
     */
    public OptionalEntity<Map<String, Object>> getDocumentByDocId(final String docId, final String[] fields,
            final OptionalThing<FessUserBean> userBean) {

    }

    /**
     * Retrieves a character mapping item by its ID.
     *
     * @param id the unique identifier of the mapping item to retrieve
     * @return an OptionalEntity containing the mapping item if found, empty otherwise
     */
    @Override
    public OptionalEntity<CharMappingItem> get(final long id) {
        if (mappingItemList == null) {
            reload(null);
        }