+ /**
+ * The additional fee we're willing to pay to avoid waiting for the counterparty's
+ * `to_self_delay` to reclaim funds.
+ *
+ * When we close a channel cooperatively with our counterparty, we negotiate a fee for the
+ * closing transaction which both sides find acceptable, ultimately paid by the channel
+ * funder/initiator.
+ *
+ * When we are the funder, because we have to pay the channel closing fee, we bound the
+ * acceptable fee by our [`Background`] and [`Normal`] fees, with the upper bound increased by
+ * this value. Because the on-chain fee we'd pay to force-close the channel is kept near our
+ * [`Normal`] feerate during normal operation, this value represents the additional fee we're
+ * willing to pay in order to avoid waiting for our counterparty's to_self_delay to reclaim our
+ * funds.
+ *
+ * When we are not the funder, we require the closing transaction fee pay at least our
+ * [`Background`] fee estimate, but allow our counterparty to pay as much fee as they like.
+ * Thus, this value is ignored when we are not the funder.
+ *
+ * Default value: 1000 satoshis.
+ *
+ * [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
+ * [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
+ */