def METHOD_NAME(self):
    event_handler = unittest.mock.Mock()
    cockpit.events.subscribe(cockpit.events.FILTER_CHANGE, event_handler)
    try:
        camera = cockpit.handlers.camera.CameraHandler(**self.args)
        camera.updateFilter('test-dye', 512.0)
    finally:
        cockpit.events.unsubscribe(cockpit.events.FILTER_CHANGE, event_handler)
    event_handler.assert_called_once()
    self.assertEqual(camera.dye, 'test-dye')
    self.assertEqual(camera.wavelength, 512.0)