async def METHOD_NAME(jp_fetch, notebook):
    r = await jp_fetch(
        "nbconvert",
        "python",
        "foo",
        "testnb.ipynb",
        method="GET",
        params={"download": True},
    )
    content_disposition = r.headers["Content-Disposition"]
    assert "attachment" in content_disposition
    assert "testnb.py" in content_disposition