Update Lib/test/test_asyncio/test_taskgroups.py

Author: graingert

Lib/test/test_asyncio/test_taskgroups.py

@@ -1084,6 +1084,10 @@ async def throw_error():
         else:
             self.fail("should have raised one MyError in group")
 
+        # if this test fails this current task will be cancelled
+        # outside the TG and inside unittest internals
+        # we add somewhere to cancel here so the test failure message
+        # is more understandable
         await asyncio.sleep(0)