def add_firewall_rule(self, FirewallRule):
return self.cloud_manager.create_firewall_rule(self, FirewallRule.to_dict())<EOL>
Add the specified FirewallRule to this server.

Returns a FirewallRule instance that is associated with this server instance.

Instantly calls the API, no need to call .save(). This is because firewall can not
be configured with the same request as the rest of the Server.