lib 1400188 // image4j (https://sourceforge.net/projects/image4j/files/image4j-core/0.7.2/)

import net.sf.image4j.codec.ico.ICOEncoder;

static byte[] toICO(BufferedImage img) ctex {
  new ByteArrayOutputStream baos;
  ICOEncoder.write(img, baos);
  ret baos.toByteArray();
}