Hold, as a template

#[weld::template]
struct Proposal {
    #[signatory] sender: Party,
    #[observer]  recipient: Party,
    asset: Asset, amount: u128,
    recipient_fi: FiIndex, deadline_bucket: Field,
    payload_root: Field,
}
impl Proposal {
    #[choice(controllers = [self.recipient], consuming)]
    fn accept(self, tx: Tx) -> (Verdict, Effects) {
        (Verdict::ok(), Effects::new().pay_from_bound(self.recipient, self.asset, self.amount))
    }
    #[choice(controllers = [], consuming)]                 // any actor vouched by recipient_fi
    fn reject(self, tx: Tx) -> (Verdict, Effects) {
        let v = Verdict::require(tx.fi_indices().contains(self.recipient_fi), "hold/wrong-fi");
        (v, Effects::new().pay_from_bound(self.sender, self.asset, self.amount))
    }
    #[choice(controllers = [self.sender], consuming)]
    fn reclaim(self, tx: Tx) -> (Verdict, Effects) {
        let v = Verdict::require(tx.time_bucket() > self.deadline_bucket, "hold/not-expired");
        (v, Effects::new().pay_from_bound(self.sender, self.asset, self.amount))
    }
}