@Test
public void targetIsNull() {

    TableSpec t = spec("table1", names("c1", "c2"), names("v1", "v2"));
    PartitionComparator comparator = comparator(t, rows(row(t, 0, 1, 2, 3)), null);
    PartitionStats stats = comparator.call();
    assertStats(stats, true, true, 0, 0, 0);
}