def send_empty(self, message):
        host, port = message.destination
        key_token = hash(str(host) + str(port) + str(message.token))
        if key_token in self._relations and message.type == defines.Types["RST"]:
            del self._relations[key_token]
        return message
Models module can be loaded from an app in an egg
dataset/ETHPy150Open Tanganelli/CoAPthon/coapthon/layers/observelayer.py/ObserveLayer.send_empty--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/tests/regressiontests/app_loading/tests.py/EggLoadingTest.test_egg1