/**
     * Write the provided data to JSON, e.g.
     *
     * <pre>
     * {
     *    "OuterKey_1": {
     *       "SubKey_1_1": 1,
     *       "SubKey_1_2": 2
     *    },
     *    "OuterKey_2": {
     *       "SubKey_2_1": 1,
     *       "SubKey_2_2": 2,
     *       "SubKey_2_3": 3
     *    }
     * }
     * </pre>
     * @param data The data to print
     * @param os The stream to which the JSON will be written
     * @throws IOException
     */
    public static void writeToJSON(Hashtable<String,Hashtable<String,Integer>> data, OutputStream os)
                                                                                    throws IOException {

        Escaper esc = new Escaper(false);

        PrintWriter pw = new PrintWriter(os,true);
        pw.println("{");

        if(data == null){
            pw.println("}");
            return;
        }

        Enumeration<String> outerKeys = data.keys();
        while(outerKeys.hasMoreElements()) {

            String outerKey = outerKeys.nextElement();



            //  "outerKey": {
            pw.println(String.format("\t\"%s\": { ", esc.escapeJsonString(outerKey)));

            Hashtable<String,Integer> innerData = data.get(outerKey);
            Enumeration<String> innerKeys = innerData.keys();
            while(innerKeys.hasMoreElements()){

                String innerKey = innerKeys.nextElement();
                //     "innerKey": innerVal
                pw.print(String.format("\t\t\"%s\": %d ", esc.escapeJsonString(innerKey), innerData.get(innerKey)));
                pw.println(innerKeys.hasMoreElements() ? ",":"");

            }
            pw.print("\t}");
            pw.println(outerKeys.hasMoreElements() ? ",":"");
        }


        pw.println("}");


    }