Tweak docs of StreamMuxer::poll_event

core/src/muxing.rs

@@ -91,6 +91,9 @@ pub trait StreamMuxer {
     /// is ready to be polled, similar to the API of `Stream::poll()`.
     /// Only the latest task that was used to call this method may be notified.
     ///
+    /// It is permissible and common to use this method to perform background
+    /// work, such as processing incoming packets and polling timers.
+    ///
     /// An error can be generated if the connection has been closed.
     fn poll_event(&self, cx: &mut Context<'_>) -> Poll<Result<StreamMuxerEvent<Self::Substream>, Self::Error>>;