Function hold_applies 

fn hold_applies(
    auth_via: ReactiveAuthVia,
    req: &InjectionRequest,
    resp: &InjectionResponse,
) -> bool

The conditions under which this instance may hold a jekt at all (durable jekt spec §2.1): a full-key, host-tier request (a LAN caller never fills the hold); not a periodic cron fire; and an id to key the row by.