Asynchronous.event_loop should get the existing event loop, if one exists. I one does not exist, it should create a new event loop then set the event loop by calling asyncio.set_event_loop so downstream consumers can get access to the same event loop when they call asyncio.get_event_loop.

@property
def event_loop(self):
    if self._loop_ref is None:
        self._loop_ref = asyncio.new_event_loop()  <!-- never sets event loop
    return self._loop_ref