code: func generateReservedVersion() VersionNumber {
  	b := make([]byte, 4)
  	_, _ = rand.Read(b) // ignore the error here. Failure to read random data doesn't break anything
  	return VersionNumber((binary.BigEndian.Uint32(b) | 0x0a0a0a0a) & 0xfafafafa)
  }
docs: // generateReservedVersion generates a reserved version number (v & 0x0f0f0f0f == 0x0a0a0a0a)