paths.go
func fwrulePath(dcid, srvid, nicid, fwruleid string) string {
	return fwruleColPath(dcid, srvid, nicid) + slash(fwruleid)
}
func fwrulePath(dcid, srvid, nicid, fwruleid string) string {
	return fwruleColPath(dcid, srvid, nicid) + slash(fwruleid)
}
// fwrule_path returns the string
//  "/datacenters/<dcid>/servers/<srvid>/nics/<nicid>/firewallrules/<fwruleid>"