/**
     * Set the value of hostname, used in parameter comment. <br>
     * Even if empty string, treated as empty plainly. So "IF pmb != null" is false if empty.
     * @param hostname The parameter value of hostname. (NotNull)
     */
    public void setHostname(String hostname) {
        registerVariable("hostname", hostname);
    }

    /**

                // State has changed
                return true;
            }

            @Override
            public String getHostname() {
                return "test-hostname";
            }
        };

        FessConfig fessConfig = createTestFessConfig();

        // Register components
        ComponentUtil.register(searchEngineClient, "searchEngineClient");

        final String hostname = ComponentUtil.getSystemHelper().getHostname();
        final String targetName = ComponentUtil.getFessConfig().getSchedulerTargetName();

        final String body = toJson(Map.of( //
                "type", TYPE_HEARTBEAT, //
                "instanceId", instanceId, //
                "hostname", hostname, //

    }

    /**
     * Gets host information including hostname and IP address.
     *
     * @return formatted string containing hostname and IP address
     */
    protected String getHostInfo() {
        final StringBuilder buf = new StringBuilder();
        try {
            final InetAddress ia = InetAddress.getLocalHost();
            final String hostname = ia.getHostName();

            false, false, false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);
    protected final ColumnInfo _columnHostname = cci("hostname", "hostname", null, null, String.class, "hostname", null, false, false,
            false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);

            false, false, "Long", 0, 0, null, null, false, null, null, null, null, null, false);
    protected final ColumnInfo _columnHostname = cci("hostname", "hostname", null, null, String.class, "hostname", null, false, false,
            false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);

    }

    /**
     * Gets the hostname of the local machine.
     *
     * @return The hostname.
     */
    public String getHostname() {
        final Map<String, String> env = getEnvMap();
        if (env.containsKey("COMPUTERNAME")) {
            return env.get("COMPUTERNAME");
        }
        if (env.containsKey("HOSTNAME")) {
            return env.get("HOSTNAME");
        }
        try {

        } finally {
            envMap.remove("COMPUTERNAME");
        }
        try {
            envMap.put("HOSTNAME", "yyy");
            assertEquals("yyy", systemHelper.getHostname());
        } finally {
            envMap.remove("HOSTNAME");
        }
    }

    @Test
    public void test_getInstanceId_withoutTargetName() {

                if (Constants.SAMBA.equals(scheme)) {
                    final String domain = paramMap.get(CRAWLER_FILE_AUTH + "." + fileAuthName + ".domain");
                    final String hostname = paramMap.get(CRAWLER_FILE_AUTH + "." + fileAuthName + ".host");
                    final String port = paramMap.get(CRAWLER_FILE_AUTH + "." + fileAuthName + ".port");

    Logger getLogger();

    /**
     * Extracts the host name from a URL string.
     * Removes protocol and path components to return just the hostname.
     *
     * @param u the URL string to extract host from
     * @return the host name, or empty string if URL is blank, or unknown hostname if parsing fails
     */
    default String getHost(final String u) {
        if (StringUtil.isBlank(u)) {