code: @Override
      public Builder expirationTime(long exp) throws InvalidClaimException {
  
          long currTime = System.currentTimeMillis() / 1000;
          if (exp >= currTime) {
              // if (exp > (new Date()).getTime()) {
              claims.put(Claims.EXPIRATION, Long.valueOf(exp));
          } else {
              // Expiration must be greater than the current time
              String err = Tr.formatMessage(tc, "JWT_INVALID_EXP_CLAIM_ERR", new Object[] { Claims.EXPIRATION, exp, JwtUtils.getDate(exp), JwtUtils.getDate(currTime) });
              throw new InvalidClaimException(err);
          }
          return this;
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.security.jwt.internal.Builder#expirationTime(long)