Creates frontend and backend for a XPUB/XSUB forwarding device

def xpubsubSockets(self, hostSub, portSub, hostPub, portPub):
        '''
        Creates frontend and backend for a XPUB/XSUB forwarding device
        '''
        frontend_addr = self.tcpAddress(hostSub, portSub)
        backend_addr = self.tcpAddress(hostPub, portPub)

        frontendSocket = self._context.socket(zmq.SUB)
        frontendSocket.bind(frontend_addr)
        frontendSocket.setsockopt(zmq.SUBSCRIBE, b'')

        backendSocket = self._context.socket(zmq.PUB)
        backendSocket.bind(backend_addr)

        return frontendSocket, backendSocket