async def METHOD_NAME(self, aresponses: ResponsesMockServer):
    aresponses.add(
        aresponses.ANY, aresponses.ANY, "get", aresponses.Response(status=200, body=b"\f" * 10)
    )
    # https://github.com/Tinche/aiofiles#writing-tests-for-aiofiles
    aiofiles.threadpool.wrap.register(MagicMock)(
        lambda *args, **kwargs: aiofiles.threadpool.binary.AsyncBufferedIOBase(*args, **kwargs)
    )
    mock_file = MagicMock()
    bot = Bot("42:TEST")
    with patch("aiofiles.threadpool.sync_open", return_value=mock_file):
        await bot.download_file("TEST", "file.png")
        mock_file.write.assert_called_once_with(b"\f" * 10)