def setUp(self):
        super(NotifierListTestCase, self).setUp()
        list_notifier._reset_drivers()
        # Mock log to add one to exception_count when log.exception is called

        def mock_exception(cls, *args):
            self.exception_count += 1

        self.exception_count = 0
        list_notifier_log = logging.getLogger(
            'openstack.common.notifier.list_notifier')
        self.stubs.Set(list_notifier_log, "exception", mock_exception)
        # Mock no_op notifier to add one to notify_count when called.

        def mock_notify(cls, *args):
            self.notify_count += 1

        self.notify_count = 0
        self.stubs.Set(no_op_notifier, 'notify', mock_notify)
        # Mock log_notifier to raise RuntimeError when called.

        def mock_notify2(cls, *args):
            raise RuntimeError("Bad notifier.")

        self.stubs.Set(log_notifier, 'notify', mock_notify2)
 def tearDown(self):
     list_notifier._reset_drivers()
     super(NotifierListTestCase, self).tearDown()