### Question:
HubBlacklistDAOFileImpl implements HubBlacklistDAO, ResourceListener { @Override public void delete(BlacklistedHub hub) { if (hub != null && hub.getCertSn() != null) { getCachedData().remove(hub.getCertSn()); } } HubBlacklistDAOFileImpl(); @PostConstruct void init(); @Override BlacklistedHub findBlacklistedHubByCertSn(String certSn); @Override BlacklistedHub save(BlacklistedHub hub); @Override void delete(BlacklistedHub hub); @Override void onChange();  }### Answer:
@Test public void testDelete() { String cert = "testSaveCert1"; BlacklistedHub newHub = createNew(cert); assertNotNull(newHub); BlacklistedHub fromDb = hubBlacklistDAO.findBlacklistedHubByCertSn(cert); assertNotNull(fromDb); hubBlacklistDAO.delete(fromDb); fromDb = hubBlacklistDAO.findBlacklistedHubByCertSn(cert); assertNull(fromDb); }