async def METHOD_NAME() -> None:
    """Test run may be cancelled."""
    async def run_error() -> str:
        await asyncio.sleep(0.1)
        return "Never"
    class ErrorApp(App):
        pass
    app = ErrorApp()
    async with app.run_test():
        worker: Worker[str] = Worker(app, run_error)
        worker._start(app)
        await asyncio.sleep(0)
        worker.cancel()
        assert worker.is_cancelled
        with pytest.raises(WorkerCancelled):
            await worker.wait()