def cancel_port_forward(self, address, port):
if not self.active:<EOL><INDENT>return<EOL><DEDENT>self._tcp_handler = None<EOL>self.global_request("<STR_LIT>", (address, port), wait=True)<EOL>
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