  @Test
  public void test_equal() {

    // mocking
    Cell cell1 = Mockito.mock(Cell.class);
    Mockito.when(cell1.getTimestamp()).thenReturn(13945345808L);
    Cell cell2 = Mockito.mock(Cell.class);
    Mockito.when(cell2.getTimestamp()).thenReturn(13945345808L);

    CellTimestampComparator comparator = new CellTimestampComparator();

    // actual call and verify
    Assert.assertTrue(comparator.compare(cell2, cell1) == 0);

  }