def test_capture(self):
        """
        Events logged within context are captured.
        """
        foo = object()

        with capturedLogs() as captured:
            self.log.debug("Capture this, please", foo=foo)
            self.log.info("Capture this too, please", foo=foo)

        self.assertTrue(len(captured) == 2)
        self.assertEqual(captured[0]["log_format"], "Capture this, please")
        self.assertEqual(captured[0]["log_level"], LogLevel.debug)
        self.assertEqual(captured[0]["foo"], foo)
        self.assertEqual(captured[1]["log_format"], "Capture this too, please")
        self.assertEqual(captured[1]["log_level"], LogLevel.info)
        self.assertEqual(captured[1]["foo"], foo)

        Events logged within context are captured.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/logger/test/test_capture.py