// We use big-endian as DataOutputStream does
sclass ByteHead /*is DataOutput*/ {
  settable bool readMode;
  settable bool writeMode;
  settable OutputStream outputStream;
  
  *() {}
  *(OutputStream *outputStream) { writeMode(true); }
  
  void writeShort(int i) {
    write(i >> 8);
    write(i);
  }
  
  void writeByte aka write(int i) ctex {
    ensureWriteMode();
    outputStream.write(i);
  }
  
  void ensureWriteMode {
    if (!writeMode) fail("Not in write mode");
  }
}