+ /**
+ * Indicates we've received money! Just gotta dig out that payment preimage and feed it to
+ * [`ChannelManager::claim_funds`] to get it....
+ * Note that if the preimage is not known, you should call
+ * [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
+ * network congestion.
+ * If you fail to call either [`ChannelManager::claim_funds`] or
+ * [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
+ * automatically failed.
+ *
+ * [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ * [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
+ */