def test_remove_dirty_rect(self): """ module canvas: Canvas.remove_dirty_rect() """ cv = Canvas(10, 10) cv.add_dirty_rect(4, 4, 2, 2) self.assertEqual(0, cv.remove_dirty_rect(4, 4, 2, 2)) self.assertRaises(CanvasError, cv.remove_dirty_rect, 11, 11, 20, 20)