How to use the nose2.events.TestOutcomeEvent function in nose2

def test_outcome_processing_successful_test(self):
        test_function = _test_func
        ev = events.TestOutcomeEvent(test_function, None, result.PASS)

        reporter = create_plugin_instance()
        reporter.testOutcome(ev)

        self.assertEqual(len(reporter.test_results), 1, 'Actual contents: %s' % reporter.test_results)
        test_result = reporter.test_results[0]
        self.assertEqual(test_result['result'], result.PASS)
        self.assertEqual(test_result['name'], test_function.__name__)
        self.assertEqual(test_result['description'], test_function.__doc__)
        self.assertIsNone(test_result['traceback'])

def test_summary_stats_increment(self):
        ev = events.TestOutcomeEvent(_test_func, None, result.PASS)
        reporter = create_plugin_instance()
        reporter.summary_stats['passed'] = 10
        reporter.testOutcome(ev)

        self.assertIn('passed', reporter.summary_stats)
        self.assertEqual(reporter.summary_stats['passed'], 11)

def test_summary_stats_total(self):
        ev = events.TestOutcomeEvent(_test_func, None, result.PASS)
        reporter = create_plugin_instance()
        for i in range(0, 20):
            reporter.testOutcome(ev)

        self.assertIn('passed', reporter.summary_stats)
        self.assertEqual(reporter.summary_stats['total'], 20)

def addFailure(self, test, err):
        """Test case resulted in failure.

        Fires :func:`setTestOutcome` and :func:`testOutcome` hooks.

        """
        event = events.TestOutcomeEvent(test, self, FAIL, err)
        self.session.hooks.setTestOutcome(event)
        self.session.hooks.testOutcome(event)

def addUnexpectedSuccess(self, test):
        """Test case resulted in unexpected success.

        Fires :func:`setTestOutcome` and :func:`testOutcome` hooks.

        """
        event = events.TestOutcomeEvent(test, self, PASS)
        self.session.hooks.setTestOutcome(event)
        self.session.hooks.testOutcome(event)

def __init__(self, test, result, outcome, exc_info=None, reason=None,
                 expected=False, shortLabel=None, longLabel=None, **kw):
        self.test = test
        self.result = result
        self.outcome = outcome
        self.exc_info = exc_info
        self.reason = reason
        self.expected = expected
        self.shortLabel = shortLabel
        self.longLabel = longLabel
        super(TestOutcomeEvent, self).__init__(**kw)

def addSkip(self, test, reason):
        """Test case was skipped.

        Fires :func:`setTestOutcome` and :func:`testOutcome` hooks.

        """
        event = events.TestOutcomeEvent(test, self, SKIP, reason=reason)
        self.session.hooks.setTestOutcome(event)
        self.session.hooks.testOutcome(event)

def addSuccess(self, test):
        """Test case resulted in success.

        Fires :func:`setTestOutcome` and :func:`testOutcome` hooks.

        """
        event = events.TestOutcomeEvent(test, self, PASS, expected=True)
        self.session.hooks.setTestOutcome(event)
        self.session.hooks.testOutcome(event)