private void incCount(String featureType, String featureValue) {

		if (!featureValueFrequency.containsKey(featureType)) {
			MultiSet<String> featureValues = new MultiSet<String>();
			featureValueFrequency.put(featureType, featureValues);
		}
		featureValueFrequency.get(featureType).add(featureValue);
	}