relay_messages.go
func (f lazyCallReq) SetTTL(d time.Duration) {
	ttl := uint32(d / time.Millisecond)
	binary.BigEndian.PutUint32(f.Payload[_ttlIndex:_ttlIndex+_ttlLen], ttl)
}
func (f lazyCallReq) SetTTL(d time.Duration) {
	ttl := uint32(d / time.Millisecond)
	binary.BigEndian.PutUint32(f.Payload[_ttlIndex:_ttlIndex+_ttlLen], ttl)
}
// SetTTL overwrites the frame's TTL.