source.put("TestKey", "value1");
        source.put("AnotherTestKey", "value2");

        Map<String, Object> nested = new HashMap<>();
        nested.put("NestedKey", "nestedValue");
        source.put("NestedMap", nested);

        Map<String, Object> result = searchLogHelper.toLowerHyphen(source);

        assertEquals("value1", result.get("test_key"));

            final String key = e.getKey();
            Object value = e.getValue();
            if (value == null) {
                value = StringUtil.EMPTY;
            }
            if (value instanceof String || value == null) {
                return new Pair<>(key, value);
            }
            if (arrayFieldSet.contains(key)) {
                if (value instanceof String[]) {

            }
        }
    }

    /**
     * Retrieves a value from a map with a default fallback.
     *
     * @param dataMap the map to retrieve the value from
     * @param key the key to look up
     * @param defaultValue the default value to return if key is not found or value is blank
     * @return the value from the map or the default value
     */

        fessConfig.setSystemProperty("spnego.allow.unsecure.basic", String.valueOf(isCheckboxEnabled(form.spnegoAllowUnsecureBasic)));
        fessConfig.setSystemProperty("spnego.prompt.ntlm", String.valueOf(isCheckboxEnabled(form.spnegoPromptNtlm)));
        fessConfig.setSystemProperty("spnego.allow.localhost", String.valueOf(isCheckboxEnabled(form.spnegoAllowLocalhost)));

        final String[] values = servletPath.replaceAll("/+", "/").split("/");
        final String value = values.length > 3 ? values[3] : null;
        if (value == null) {
            return FormatType.SEARCH;
        }
        final String type = value.toLowerCase(Locale.ROOT);
        if ("documents".equals(type)) {
            if (values.length > 5 && "favorite".equals(values[5])) {

            return defaultLang;
        }

        return normalizeLang(value);
    }

    /**
     * Normalizes a language string.
     *
     * @param value The language string to normalize.
     * @return The normalized language string.
     */
    public String normalizeLang(final String value) {
        if (StringUtil.isBlank(value)) {
            return null;
        }

    /** Property key for default label value configuration. */
    public static final String DEFAULT_LABEL_VALUE_PROPERTY = "label.value";

    /** Property key for default sort value configuration. */
    public static final String DEFAULT_SORT_VALUE_PROPERTY = "sort.value";

    /** Property key for virtual host value configuration. */

        }
    }

    /**
     * Parses and validates field filter parameters from the request.
     * Only configured label values are accepted to prevent query injection.
     *
     * @param request the HTTP request
     * @return a map of field names to their validated filter values
     */
    protected Map<String, String[]> parseFieldFilters(final HttpServletRequest request) {

        value = "ja-JP";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "ja_JP";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "ja_JP_AAA";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "zh";
        assertEquals("zh", systemHelper.normalizeLang(value));

        value = "zh-cn";

                    }
                    postcard.setHostname(systemHelper.getHostname());
                    postcard.setLevel(level);
                    postcard.setCount(String.valueOf(levelEvents.size()));
                    postcard.setInterval(String.valueOf(fessConfig.getLogNotificationIntervalAsInteger()));
                    postcard.setDetails(details);
                });
            } catch (final Exception e) {