When closing a StreamReader e.g. as in:

 sr, sw = await asyncio.open_connection(host, port, ssl=use_ssl)
 # ....
 await sr.aclose()

the program will crash. My code runs also on cpython and interestingly the corresponding StreamReader on that platform doesn't even have a .close() method.

So my the questions is: am I even supposed to call sr.aclose() (and if not why does it exist)?