public static void WriteBytes(Span <byte> destination, int value)
 {
     UnsafeBitConverter.WriteBytes(destination, IPAddress.HostToNetworkOrder(value));
 }
 private void WriteMagicCookie(Span <byte> bytes)
 {
     UnsafeBitConverter.WriteBytes(bytes.Slice(4, 4), StunMagicCookie);
 }