public static TimestampRange of(Timestamp from, Timestamp to) {
    return new TimestampRange(from, to);
  }
@Test
  public void testTimestampRangeWhenFromIsEqualToTo() {
    assertEquals(
        new TimestampRange(Timestamp.ofTimeMicroseconds(10L), Timestamp.ofTimeMicroseconds(10L)),
        TimestampRange.of(Timestamp.ofTimeMicroseconds(10L), Timestamp.ofTimeMicroseconds(10L)));
  }