public BDD buildCube(int value, Collection variables) {
public BDD buildCube(int value, List variables) {
    public BDD buildCube(int value, Collection/*BDD*/ variables) {        BDD result = one();        Iterator i = variables.iterator();        int z=0;        while (i.hasNext()) {            BDD var = (BDD) i.next();            if ((value & 0x1) != 0)                var = var.id();            else                var = var.not();            result.andWith(var);            ++z;            value >>= 1;        }        return result;    }