it just feels odd for the variable to be named `Authorization` but it's actually an `AuthorizationReq`, so I suggested this might be because of which `struct` is responsible for certain metadata.

For example, I think it's an `Authorization` (struct) that technically has a TTL, not the `AuthorizationReq`.  I think the `AuthorizationReq` is ephemeral, we can create and discard one in local scope whenever we make the request... it's the `Authorization` that are longer lived and should be hung off `ClientV2` (but this implies some metadata gets moved around).