@Test
public void doClean() {
PurgeDao dao = mock(PurgeDao.class);
DbSession session = mock(DbSession.class);
when(dao.selectPurgeableSnapshots(123L, session)).thenReturn(Arrays.asList(
new PurgeableSnapshotDto().setSnapshotId(999L).setDate(new Date())));
Filter filter1 = newLazyFilter();
Filter filter2 = newLazyFilter();
DefaultPeriodCleaner cleaner = new DefaultPeriodCleaner(dao, mock(Settings.class), mock(MyBatis.class));