int compare(ByteString a, ByteString b) {
    ByteIterator itA = a.iterator();
    ByteIterator itB = b.iterator();

    while (itA.hasNext()) {
        if (!itB.hasNext()) {
            return -1;
        }

        int bA = itA.nextByte() & 0xff;
        int bB = itB.nextByte() & 0xff;

        int c = Integer.compare(bA, bB);

        if (c != 0) {
            return c;
        }
    }

    if (itB.hasNext()) {
        return 1;
    }

    return 0;
}
 

private String asHexString(ByteString id) {
  ByteIterator iterator = id.iterator();
  StringBuilder out = new StringBuilder();
  while (iterator.hasNext()) {
    byte b = iterator.nextByte();
    out.append(HEXES.charAt((b & 0xF0) >> 4)).append(HEXES.charAt((b & 0x0F)));
  }
  return out.toString();
}
 

private String asHexString(ByteString id) {
    ByteIterator iterator = id.iterator();
    StringBuilder out = new StringBuilder();
    while (iterator.hasNext()) {
        byte b = iterator.nextByte();
        out.append(HEXES.charAt((b & 0xF0) >> 4)).append(HEXES.charAt((b & 0x0F)));
    }
    return out.toString();
}