self.prev_local_htlc_sigs = Some(Vec::new());
let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
self.prev_local_htlc_sigs = Some(Vec::new());
let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {