def test_frames(self):
        frame_snuffling = DummySnuffling()

        self.viewer.add_snuffling(frame_snuffling)
        frame_snuffling.call()

        # close three opened frames
        QTest.keyPress(self.pile_viewer, 'd')
        QTest.keyPress(self.pile_viewer, 'd')
        QTest.keyPress(self.pile_viewer, 'd')