f add comment requested by val

Author: TheBlueMatt

lightning/src/ln/functional_test_utils.rs

@@ -797,6 +797,8 @@ pub fn send_along_route_with_secret<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>,
 
 			if idx == expected_route.len() - 1 {
 				let events_2 = node.node.get_and_clear_pending_events();
+				// Once we've gotten through all the HTLCs, the last one should result in a
+				// PaymentReceived (but each previous one should not!).
 				if path_idx == expected_paths.len() - 1 {
 					assert_eq!(events_2.len(), 1);
 					match events_2[0] {