code: private void checkJwtClaims(JwtClaims jwtClaims) {
      Optional<NumericDate> expiration = getDateClaim(ReservedClaimNames.EXPIRATION_TIME, jwtClaims);
      if (!expiration.isPresent()) {
        throw new UnauthenticatedException("Missing expiration field");
      }
      Optional<NumericDate> notBefore = getDateClaim(ReservedClaimNames.NOT_BEFORE, jwtClaims);
  
      NumericDate currentTime = NumericDate.fromMilliseconds(clock.currentTimeMillis());
      if (expiration.get().isBefore(currentTime)) {
        throw new UnauthenticatedException("The auth token has already expired");
      }
  
      if (notBefore.isPresent() && notBefore.get().isAfter(currentTime)) {
        String message = "Current time is earlier than the \"nbf\" time";
        throw new UnauthenticatedException(message);
      }
    }
docs: Check whether the JWT claims should be accepted.