### Question:
DataUtils { static boolean isTimeValid(TimeStamp timeStamp) { if (timeStamp == null) return false; long sec = timeStamp.secPastEpoch() + TS_EPOCH_SEC_PAST_1970; if (sec == 0 || sec == TS_EPOCH_SEC_PAST_1970) { return false; } long nanosec = timeStamp.nsec(); if (nanosec < 0 || nanosec > 999_999_999) { return false; } return true; }    }### Answer:
@Test public void isTimeValid1() { TimeStamp timeStamp = new TimeStamp(123456789, 1234567890); assertThat(DataUtils.isTimeValid(timeStamp), equalTo(false)); }
@Test public void isTimeValid2() { TimeStamp timeStamp = new TimeStamp(123456789, 123456789); assertThat(DataUtils.isTimeValid(timeStamp), equalTo(true)); }