func (c *genericOpt) SetHopLimit(hoplim int) error {
	return errOpNoSupport
}
SetHopLimit sets the hop limit field value for future outgoing
packets.
package ipv6
func (c *genericOpt) TrafficClass() (int, error) {
	return 0, errOpNoSupport
}
func (c *genericOpt) SetTrafficClass(tclass int) error {
	return errOpNoSupport
}
func (c *genericOpt) HopLimit() (int, error) {
	return 0, errOpNoSupport
}