/** The key of the configuration. e.g. 0-1 */
    String INDEX_auto_expand_replicas = "index.auto_expand_replicas";

    /** The key of the configuration. e.g. SHA-512 */
    String INDEX_ID_DIGEST_ALGORITHM = "index.id.digest.algorithm";

    /** The key of the configuration. e.g. admin */
    String INDEX_USER_initial_password = "index.user.initial_password";

        assertEquals("31f30ddbcb1bf8446576f0e64aa4c88a9f055e3c", MessageDigestUtil.digest("SHA-1", text));
        assertEquals("ecb666d778725ec97307044d642bf4d160aabb76f56c0069c71ea25b1e926825", MessageDigestUtil.digest("SHA-256", text));

        try {
            MessageDigestUtil.digest(null, text);
            assertTrue(false);