We should be able to import `DeliveryEnum`

[gordonwatts]

This is used in the front-end:

    spec = sx.ServiceXSpec(
        General=sx.General(
            ServiceX="atlasr22",
            Codegen=query[1],
            OutputFormat=sx.ResultFormat.root,  # type: ignore
            Delivery=("LocalCache" if download else "SignedURLs"),  # type: ignore  <== HERE
        ),
        Sample=[
            # TODO: Need a way to have the DID finder re-fetch the file list.
            sx.Sample(
                Name=f"speed_test_{ds_name}"[0:128],
                RucioDID=ds_name,
                Codegen=query[1],
                Query=query[0],
                NFiles=num_files,
                IgnoreLocalCache=ignore_cache,
            )  # type: ignore
            for ds_name in ds_names
        ],
    )

# TODO: Where is the enum that does DeliveryEnum come from?