@abc.abstractmethod<EOL><INDENT>def floating_ip_added(self, router_info, ext_gw_port,<EOL>floating_ip, fixed_ip):<DEDENT>
pass<EOL>
A floating IP was added.

        :param router_info: RouterInfo object for this router
        :param ext_gw_port: port dictionary for the port where the external
            gateway network is connected
        :param floating_ip: Floating IP as a string
        :param fixed_ip: Fixed IP of internal internal interface as a string
        :returns: None