@Test
public void testGetUpdatedSignedDomainsNull() throws InterruptedException, IOException, KeyRefresherException {

    MockZMSFileMTLSChangeLogStore store = new MockZMSFileMTLSChangeLogStore(FSTORE_PATH, keyPath, certPath,
            trustStorePath, trustStorePassword);
    store.setSignedDomainsExc();
    StringBuilder str = new StringBuilder();
    assertNull(store.getUpdatedSignedDomains(str));
}