public static void addInternalConfig(ConfigDef configDef) {
        configDef
                .define(
                        LISTENERS_CONFIG,
                        ConfigDef.Type.LIST,
                        LISTENERS_DEFAULT,
                        new ListenersValidator(),
                        ConfigDef.Importance.LOW,
                        LISTENERS_DOC
                ).define(
                        REST_ADVERTISED_HOST_NAME_CONFIG,
                        ConfigDef.Type.STRING,
                        null,
                        ConfigDef.Importance.LOW,
                        REST_ADVERTISED_HOST_NAME_DOC
                ).define(
                        REST_ADVERTISED_PORT_CONFIG,
                        ConfigDef.Type.INT,
                        null,
                        ConfigDef.Importance.LOW,
                        REST_ADVERTISED_PORT_DOC
                ).define(
                        REST_ADVERTISED_LISTENER_CONFIG,
                        ConfigDef.Type.STRING,
                        null,
                        ConfigDef.Importance.LOW,
                        REST_ADVERTISED_LISTENER_DOC
                ).define(
                        ACCESS_CONTROL_ALLOW_ORIGIN_CONFIG,
                        ConfigDef.Type.STRING,
                        ACCESS_CONTROL_ALLOW_ORIGIN_DEFAULT,
                        ConfigDef.Importance.LOW,
                        ACCESS_CONTROL_ALLOW_ORIGIN_DOC
                ).define(
                        ACCESS_CONTROL_ALLOW_METHODS_CONFIG,
                        ConfigDef.Type.STRING,
                        ACCESS_CONTROL_ALLOW_METHODS_DEFAULT,
                        ConfigDef.Importance.LOW,
                        ACCESS_CONTROL_ALLOW_METHODS_DOC
                ).define(
                        RESPONSE_HTTP_HEADERS_CONFIG,
                        ConfigDef.Type.STRING,
                        RESPONSE_HTTP_HEADERS_DEFAULT,
                        new ResponseHttpHeadersValidator(),
                        ConfigDef.Importance.LOW,
                        RESPONSE_HTTP_HEADERS_DOC
                ).define(
                        BrokerSecurityConfigs.SSL_CLIENT_AUTH_CONFIG,
                        ConfigDef.Type.STRING,
                        BrokerSecurityConfigs.SSL_CLIENT_AUTH_DEFAULT,
                        in(Utils.enumOptions(SslClientAuth.class)),
                        ConfigDef.Importance.LOW,
                        BrokerSecurityConfigs.SSL_CLIENT_AUTH_DOC);
    }
Add the properties related to an internal-only server to the given {@link ConfigDef}.
@param configDef the {@link ConfigDef} to add the properties to; may not be null
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/rest/RestServerConfig.java