class FstObjectInput implements ObjectInput {

    @Override
    public byte[] readBytes() throws IOException {
        int len = input.readInt();
        if (len < 0) {
            return null;
        } else if (len == 0) {
            return new byte[]{};
        } else {
            byte[] b = new byte[len];
            input.readFully(b);
            return b;
        }
    }

    public  FstObjectInput(InputStream inputStream);

}