* Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
* chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
* preimage claim backward will lead to loss of funds.
* Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
* chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
* preimage claim backward will lead to loss of funds.