public String buildJwtForLlap(ApplicationId extClientAppId) {
    return Jwts.builder()
        .setSubject(LLAP_JWT_SUBJECT)
        .setIssuedAt(new Date())
        .setId(UUID.randomUUID().toString())
        .claim(LLAP_EXT_CLIENT_APP_ID, extClientAppId.toString())
        .signWith(jwtSecretProvider.getEncryptionSecret())
        .compact();
  }
@param extClientAppId application Id - application Id injected by get_splits
@return JWT signed with {@link JwtSecretProvider#getEncryptionSecret()}.
As of now this JWT contains extClientAppId in claims.
llap-common/src/java/org/apache/hadoop/hive/llap/security/LlapExtClientJwtHelper.java