String[] fields = { "field2", "field1" };
        String[] excludes = { "exclude2", "exclude1" };

        String result1 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);
        String result2 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);

        assertEquals(result1, result2);
    }

    public void test_getCacheKey_differentOrder() {

        value = "ftp://123.123.123.123:9999/";
        ftpInfo = new FtpClient.FtpInfo(value, Constants.UTF_8);
        assertEquals(value, ftpInfo.toUrl());
        assertEquals("123.123.123.123:9999", ftpInfo.getCacheKey());
        assertEquals("123.123.123.123", ftpInfo.getHost());
        assertEquals(9999, ftpInfo.getPort());
        assertEquals("/", ftpInfo.getParent());
        assertNull(ftpInfo.getName());

     *
     * @param keyObj the crawler object to track (UrlQueue, StatsKeyObject, String, or Number)
     */
    public void begin(final Object keyObj) {
        getCacheKey(keyObj).ifPresent(key -> {
            try {
                statsCache.get(key);
            } catch (final Exception e) {
                final StringBuilder buf = createStringBuffer(keyObj, getCurrentTimeMillis());

        final String[] baseExcludes = excludes != null ? excludes : fessConfig.getSuggestPopularWordExcludesAsArray();
        try {
            return cache.get(getCacheKey(baseSeed, baseTags, baseRoles, baseFields, baseExcludes), () -> {
                final List<String> wordList = new ArrayList<>();
                final SuggestHelper suggestHelper = ComponentUtil.getSuggestHelper();

         * This key can be used to cache FTP client connections.
         *
         * @return The cache key in format "host:port"
         */
        public String getCacheKey() {
            return getHost() + ":" + getPort();
        }

        /**
         * Gets the host name from the FTP URL.
         *
         * @return The host name
         */