case 'w' :
if (listSize-- <= 0) {
throw runtime.newArgumentError(sTooFew);
}
IRubyObject from = list.eltInternal(idx++);
String stringVal = from == runtime.getNil() ? "0" : from.asString().toString();
BigInteger bigInt = new BigInteger(stringVal);
// we don't deal with negatives.
if (bigInt.compareTo(BigInteger.ZERO) >= 0) {
int bitLength = bigInt.toString(2).length();