if (value instanceof final LocalDateTime ldt) {
            final ZonedDateTime zdt = ZonedDateTime.of(ldt, ZoneId.systemDefault());
            super.addFieldToSource(sourceMap, field, DateTimeFormatter.ISO_INSTANT.format(zdt));
        } else {
            super.addFieldToSource(sourceMap, field, value);
        }
    }

    @Override

     */
    @Test
    public void test_isSearchField_performance() {
        // Create a large set of search fields
        int fieldCount = 1000;
        String[] fields = new String[fieldCount];
        for (int i = 0; i < fieldCount; i++) {
            fields[i] = "field" + i;
        }
        queryFieldConfig.setSearchFields(fields);

                return fields;
            }

            @Override
            public String[] getQueryAdditionalSearchFields(String... fields) {
                return fields;
            }

            @Override
            public String[] getQueryAdditionalFacetFields(String... fields) {
                return fields;
            }

            @Override

# Field name for document ID in the index.
index.field.doc_id=doc_id
# Field name for internal ID in the index.
index.field.id=_id
# Field name for version in the index.
index.field.version=_version
# Field name for sequence number in the index.
index.field.seq_no=_seq_no
# Field name for primary term in the index.
index.field.primary_term=_primary_term
# Field name for language in the index.
index.field.lang=lang

            final Map<String, String[]> fields = new HashMap<>();
            for (final Map.Entry<String, String[]> entry : request.getParameterMap().entrySet()) {
                final String key = entry.getKey();
                if (key.startsWith("fields.")) {
                    final String[] value = simplifyArray(entry.getValue());
                    fields.put(key.substring("fields.".length()), value);
                }

    /** The key of the configuration. e.g. url */
    String INDEX_FIELD_URL = "index.field.url";

    /** The key of the configuration. e.g. doc_id */
    String INDEX_FIELD_doc_id = "index.field.doc_id";

    /** The key of the configuration. e.g. _id */
    String INDEX_FIELD_ID = "index.field.id";

    /** The key of the configuration. e.g. _version */

                try {
                    suggester.settings().array().add(SuggestSettings.DefaultKeys.SUPPORTED_FIELDS, field);
                } catch (final SuggestSettingsException e) {
                    logger.warn("Failed to add suggest field: field={}", field, e);
                }
            }));

        assertEquals(3, fields.length);
        assertEquals("expires", fields[0]);
        assertEquals("start_time", fields[1]);
        assertEquals("end_time", fields[2]);
    }

    @Test
    public void test_indexAdminIntegerFields() {
        String[] fields = fessConfig.getIndexAdminIntegerFields().split(",");
        assertEquals(1, fields.length);

     * @param id the document ID to retrieve
     * @param fields the fields to include in the response (null for all fields)
     * @return the document as a map of field names to values, or null if not found
     */
    public Map<String, Object> getDocument(final SearchEngineClient searchEngineClient, final String id, final String[] fields) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

        // Log all available stats fields for debugging
        logger.info("Available stats fields: {}", res.keySet());

        // Verify response contains meaningful data
        assertNotNull(res, "Stats response should not be null");
        assertTrue(res.size() > 0, "Stats should contain at least some data");

        // Check for common stats fields (these may need to be adjusted based on actual implementation)