@Test(expected = IllegalArgumentException.class)
public void publishEvent() {

    PublishEventTO invalidPublishEventTO = PublishEventTO.getValidInstance(contextType, null, contextTitle, subcontextId, sourceType, sourceId, sourceTitle,
            sourceEntryTitle, creatorIdentity, EventType.NEW);
    invalidPublishEventTO.setSourceEntryId(sourceEntryId.toString());
    publishDelegateTestObject.publishEvent(invalidPublishEventTO);
}