f add comment in test

Author: TheBlueMatt

lightning/src/chain/channelmonitor.rs

@@ -3395,6 +3395,9 @@ mod tests {
 		check_closed_broadcast!(nodes[1], true);
 		check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
 
+		// Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
+		// and provides the claim preimages for the two pending HTLCs. The first update generates
+		// an error, but the point of this test is to ensure the later updates are still applied.
 		let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
 		let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
 		assert_eq!(replay_update.updates.len(), 1);