1 -class GenericCommunication: 2 3 - def start(self): 4 pass 5 6 - def stop(self): 7 pass 8 9 - def send(self,msg): 10 raise NotImplementedError 11 12 - def receive(self): 13 return [] 14 15 -class GenericMessage: 16 17 - def content(self): 18 return '' 19