async def test_bad_unsubscribe(self):
"""Assert that unsubscribing a handler that isn't registered fails."""
emitter = EventHub()
with pytest.raises(NoSuchListenerError):
emitter.unsubscribe(ExampleEvents.something_happened, self.handler)
async def test_unsubscribe_from_event(self):
"""Assert that a handler can be unsubscribed from an event."""
emitter = EventHub(ExampleEvents)
emitter.subscribe(emitter.something_happened, self.handler)
emitter.unsubscribe(emitter.something_happened, self.handler)