@Test
public void testContains() {

  column1.appendCell("05:15:30");
  column1.appendCell("10:15:30");
  column1.appendCell("07:04:02");
  assertTrue(column1.contains(LocalTime.of(5, 15, 30)));
  assertTrue(column1.contains(LocalTime.of(10, 15, 30)));
  assertFalse(column1.contains(LocalTime.of(9, 15, 30)));
}