def test_service_call_create_log_book_entry_no_message(self):
        calls = []

        def event_listener(event):
            calls.append(event)

        self.hass.bus.listen(logbook.EVENT_LOGBOOK_ENTRY, event_listener)
        self.hass.services.call(logbook.DOMAIN, 'log', {}, True)
        self.hass.pool.block_till_done()

        self.assertEqual(0, len(calls))
Test if service call create log book entry without message.
dataset/ETHPy150Open home-assistant/home-assistant/tests/components/test_logbook.py/TestComponentHistory.test_service_call_create_log_book_entry_no_message