docs/library: Note that uasyncio.wait_for() can raise exception.
@@ -67,6 +67,9 @@ Additional functions
that *timeout* seconds. If *awaitable* is not a task then a task will be
created from it.
+ If a timeout occurs, it cancels the task and raises ``asyncio.TimeoutError``:
+ this should be trapped by the caller.
+
Returns the return value of *awaitable*.
This is a coroutine.
