public String toISOString() {
        return instant.toString();
    }
@Test
    void Test_DateString_With_Pattern() {
        String pattern = "yyyy-MM-dd HH:mm:ss.SSSXXX";
        TbDate d = new TbDate("2023-08-06 04:04:05.000-04:00", pattern);
        Assertions.assertEquals("2023-08-06T08:04:05Z", d.toISOString());
    }