/** The key of the configuration. e.g. 10000 */
    String search_engine_heartbeat_interval = "search_engine.heartbeat_interval";

    /** The key of the configuration. e.g. aes */
    String APP_CIPHER_ALGORITHM = "app.cipher.algorithm";

    /** The key of the configuration. e.g. ___change__me___ */
    String APP_CIPHER_KEY = "app.cipher.key";