def purge(self):
        while not self.stopped.isSet():
            self.stopped.wait(timeout=defines.EXCHANGE_LIFETIME)
            self._messageLayer.purge()
write a filter-applying expression based on the filters
dataset/ETHPy150Open Tanganelli/CoAPthon/coapthon/server/coap.py/CoAP.purge--crossover with--dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/mako/codegen.py/_GenerateRenderMethod.create_filter_callable