private void buildTree(TeaClassifier tc, TeaNode parent, String[] valueCombo, int level, List<Integer> usedAttributes, double sugar) {
		if (length < level + 1) {
			length = level + 1;
		}
		if (parent.getAttributeNum() == 0) {
			for (String val : Tea.TEA_TYPE_VALUES) {
				buildForStringFeature(tc, parent, valueCombo, level, usedAttributes, sugar, val, 0);
			}
		} else if (parent.getAttributeNum() == 2) {
			for (String val : Tea.ADDITION_VALUES) {
				buildForStringFeature(tc, parent, valueCombo, level, usedAttributes, sugar, val, 1);
			}
		} else if (parent.getAttributeNum() == 1) {
			buildForDoubleFeature(tc, parent, valueCombo, level, usedAttributes, sugar, 1);
		}
	}