@Test
public void testGetServerSignedDomainException() {

    MockZMSFileChangeLogStore fstore = new MockZMSFileChangeLogStore(FSTORE_PATH, null, null);
    ZMSClient zmsClient = Mockito.mock(ZMSClient.class);
    fstore.setZMSClient(zmsClient);
    Mockito.when(zmsClient.getSignedDomains("athenz", null, null, null))
        .thenThrow(new ZMSClientException(500, "invalid server error:"));
    assertNull(fstore.getServerSignedDomain("athenz"));
}