public static void main(String args[]) {
    DecisionTree decisionTree = makeOutlookTree();

    Map<String, String> case1 = new HashMap<String, String>();
    case1.put("Outlook", "Overcast");
    case1.put("Temperature", "Hot");
    case1.put("Humidity", "High");
    case1.put("Wind", "Strong");

    try {
      System.out.println(decisionTree.classify(case1));
    } catch (UnknownDecisionException e) {
      System.out.println("?");
    }
  }