firewallrule.go
func (c *Client) ListFirewallRules(dcID string, serverID string, nicID string) (*FirewallRules, error) {
	url := fwruleColPath(dcID, serverID, nicID) + `?depth=` + c.client.depth + `&pretty=` + strconv.FormatBool(c.client.pretty)
	ret := &FirewallRules{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
func (c *Client) ListFirewallRules(dcID string, serverID string, nicID string) (*FirewallRules, error) {
	url := fwruleColPath(dcID, serverID, nicID) + `?depth=` + c.client.depth + `&pretty=` + strconv.FormatBool(c.client.pretty)
	ret := &FirewallRules{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
//ListFirewallRules lists all firewall rules