def test_formatEventFlatTrailingText(self):
        """
        L{formatEvent} will handle a flattened event with tailing text after
        a replacement field.
        """
        event = dict(
            log_format="test {x} trailing",
            x='value',
        )
        flattenEvent(event)

        result = formatEvent(event)

        self.assertEqual(result, u"test value trailing")

        L{formatEvent} will handle a flattened event with tailing text after
        a replacement field.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/logger/test/test_flatten.py