code: public static void setTransactionTime(Date transactionTime) {
          if (transactionTime == null) {
              String msg = "The argument 'transactionTime' should not be null.";
              throw new IllegalArgumentException(msg);
          }
          Stack<Date> stack = threadLocal.get();
          if (stack == null) {
              stack = new Stack<Date>();
              threadLocal.set(stack);
          }
          stack.push(transactionTime);
      }
docs: Set the value of the transaction time.
  @param transactionTime The value of the transaction time. (NotNull)