code: public int satOneSet(final int r, final int var, final int pol) {
      if (isZero(r))
        return r;
      if (!isConst(pol))
        throw new IllegalArgumentException("polarity for satOneSet must be a constant");
      initRef();
      return satOneSetRec(r, var, pol);
    }
docs: Returns an arbitrary model for a given BDD or {@code null} which contains at least the given variables.  If a variable
  is a don't care variable, it will be assigned with the given default value.
  @param r   the BDD root node
  @param var the set of variable which has to be contained in the model as a BDD
  @param pol the default value for don't care variables as a BDD
  @return an arbitrary model of this BDD