private static BigInteger inetAddressToBigInteger(byte[] address) {
        BigInteger bit = BigInteger.ZERO;
        for (byte b : address)
            bit = bit.shiftLeft(8).add(BigInteger.valueOf(b & 0xFF));
        return bit;
    }
@return iterable over all CIDR blocks of the same prefix size, from the current one and up
vespajlib/src/main/java/ai/vespa/net/CidrBlock.java