@Override
    public int compareTo(DateTimeStamp dateTimeStamp) {
        return  comparator.compare(this,dateTimeStamp);
    }
@Test
    void compareToTransitivityWithEqualTimeStamps() {
        DateTimeStamp stamp1 = new DateTimeStamp("2021-09-01T11:12:13.111-0100", 100);
        DateTimeStamp stamp2 = new DateTimeStamp((String)null, 100);
        DateTimeStamp stamp3 = new DateTimeStamp("2021-08-31T11:12:13.111-0100", 100);
        int comp1To2 = stamp1.compareTo(stamp2);
        int comp2To3 = stamp2.compareTo(stamp3);
        assertEquals(comp1To2, comp2To3);
        int comp1To3 = stamp1.compareTo(stamp3);
        assertEquals(comp1To2, comp1To3, "compareTo() is not transitive");
    }