f comment in test

Author: TheBlueMatt

lightning/src/ln/priv_short_conf_tests.rs

@@ -454,6 +454,9 @@ fn test_inbound_scid_alias() {
 
 #[test]
 fn test_scid_alias_returned() {
+	// Tests that when we fail an HTLC (in this case due to attempting to forward more than the
+	// channel's available balance) we use the correct (in this case the aliased) SCID in the
+	// channel_update which is returned in the onion to the sender.
 	let chanmon_cfgs = create_chanmon_cfgs(3);
 	let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
 	let mut accept_forward_cfg = test_default_channel_config();