let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
let chan_type = self.channel_type_features().expect(MISSING_PARAMS_ERR);
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, chan_type, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
let mut sighash_parts = sighash::SighashCache::new(htlc_tx);