Как заставить выполнятся?

Question

[hardwellZero]

def buttonGo(self):
        self.statusBar().showMessage('In progress...')
        scheduler = BackgroundScheduler()
        scheduler.add_job(tick(self), 'interval', seconds=3)
        scheduler.start()

        try:
            # This is here to simulate application activity (which keeps the main thread alive).
            while True:
                time.sleep(2)
        except (KeyboardInterrupt, SystemExit):
            scheduler.shutdown()  # Not strictly necessary if daemonic mode is enabled but should be done if possible

def tick(self):
    print "test"

Выводит только 1 раз и выдает ошибку -

TypeError: func must be a callable or a textual reference to one