def METHOD_NAME(mock_warn: MagicMock) -> None:
    curstate().reset()
    _, resources, _ = bis._get_save_args(curstate(), "filename", None, "title")
    assert resources.mode == "cdn"
    assert mock_warn.call_count == 1
    assert mock_warn.call_args[0] == (
        "save() called but no resources were supplied and output_file(...) was never called, defaulting to resources.CDN",
    )
    assert mock_warn.call_args[1] == {}