code: func IsV6LinkLocalAddress(addr tcpip.Address) bool {
  	if len(addr) != IPv6AddressSize {
  		return false
  	}
  	return addr[0] == 0xfe && (addr[1]&0xc0) == 0x80
  }
docs: // IsV6LinkLocalAddress determines if the provided address is an IPv6
  // link-local address (fe80::/10).