Ask the server to cancel a previous port-forwarding request.  No more
        connections to the given address & port will be forwarded across this
        ssh connection.

        :param str address: the address to stop forwarding
        :param int port: the port to stop forwarding

def cancel_port_forward(self, address, port):
        """
        Ask the server to cancel a previous port-forwarding request.  No more
        connections to the given address & port will be forwarded across this
        ssh connection.

        :param str address: the address to stop forwarding
        :param int port: the port to stop forwarding
        """
        if not self.active:
            return
        self._tcp_handler = None
        self.global_request("cancel-tcpip-forward", (address, port), wait=True)