private void refresh() throws Exception {
        long lastRefresh = readLastRefreshTime();
        long timeSinceLastRefresh = System.currentTimeMillis() - lastRefresh;

        if (timeSinceLastRefresh <= CACHE_MAX_AGE) {
            return;
        }

        MetadataResponse metadata = getTranslationsMetadata();
        if (timeSinceLastRefresh <= metadata.cacheMaxAge) {
            return;
        }

        // perform a refresh!
        downloadAndInstallTranslations(metadata.languages, null, true);
    }
Schedules a refresh of the current translations if necessary.
common/src/main/java/me/lucko/luckperms/common/locale/TranslationRepository.java