pub async fn borrowing_the_radio<E: RadioErrand>(
app: &mut App,
errand: E,
) -> Result<()>Expand description
Take the attachment over as this tool’s radio, run errand on it,
and hand the attachment back.
This tool has one radio. A command that kept it on failure would leave the session holding nothing, so the give-back is unconditional — every early return here happens before the link is consumed.