public void addFeatureOpinion(
            HashMap<String, HashMap<String, Double>> foList, String feature,
            String opinion, boolean isPositive, boolean isNegatedOpinion) {
        Double val;
        if (isPositive)
            val = reviewObj.posReviewScore;
        else
            val = reviewObj.negReviewScore;
        String newOpinion = isNegatedOpinion ? "!" + opinion : opinion;
        HashMap<String, Double> tmpHM;
        if (foList.containsKey(feature)) {
            tmpHM = foList.get(feature);
            if (tmpHM.containsKey(newOpinion)) {
                val = tmpHM.get(newOpinion);
                if (isPositive)
                    val += reviewObj.posReviewScore;
                else
                    val += reviewObj.negReviewScore;
            }
        } else {
            tmpHM = new HashMap<String, Double>();
        }
        tmpHM.put(newOpinion, val);
        foList.put(feature, tmpHM);
    }