f explain why the assertions are there

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -1706,6 +1706,10 @@ macro_rules! process_events_body {
 					$event_to_handle = event;
 					$handle_event;
 					let mut pending_events = $self.pending_events.lock().unwrap();
+					// We're required to take the `pending_events_processor` lock any time we
+					// change `pending_events`, however have no general way to enforce that.
+					// Instead, here, we assert that the next event hasn't changed out from under
+					// us.
 					#[cfg(debug_assertions)] {
 						debug_assert_eq!(_ev_clone, pending_events.front().unwrap().0);
 					}