private Map<String, Double> existsRowModel(
      Map<String, Double> mRowModel, String key, Double value) {

    if (mRowModel.get(key) == null) {
      mRowModel.put(key, value);
    } else {
      mRowModel.put(key, mRowModel.get(key) + value);
    }
    return mRowModel;
  }
  private List<RowModel> populateMonths() {
    List<Map> ds1 = (List<Map>) dataSources.get(0);
    List<RowModel> rowModels = new ArrayList<RowModel>();
    Map<String, Double> mRowModel = new HashMap<String, Double>();
    RowModel rowModel;
    Map ds = null;
    for (int j = 0; j < ds1.size(); j++) {
      ds = ds1.get(j);
      mRowModel = existsRowModel(mRowModel, "01Jan", (Double) ds.get("JAN"));
      mRowModel = existsRowModel(mRowModel, "02Feb", (Double) ds.get("FEB"));
      mRowModel = existsRowModel(mRowModel, "03Mar", (Double) ds.get("MAR"));
      mRowModel = existsRowModel(mRowModel, "04Apr", (Double) ds.get("APR"));
      mRowModel = existsRowModel(mRowModel, "05Mei", (Double) ds.get("MEI"));
      mRowModel = existsRowModel(mRowModel, "06Jun", (Double) ds.get("JUN"));
      mRowModel = existsRowModel(mRowModel, "07Jul", (Double) ds.get("JUL"));
      mRowModel = existsRowModel(mRowModel, "08Ags", (Double) ds.get("AGUS"));
      mRowModel = existsRowModel(mRowModel, "09Sep", (Double) ds.get("SEP"));
      mRowModel = existsRowModel(mRowModel, "10Okt", (Double) ds.get("OKT"));
      mRowModel = existsRowModel(mRowModel, "11Nov", (Double) ds.get("NOV"));
      mRowModel = existsRowModel(mRowModel, "12Dec", (Double) ds.get("DES"));
    }

    String key = null;
    Iterator iterator = mRowModel.keySet().iterator();
    while (iterator.hasNext()) {
      key = (String) iterator.next();
      rowModels.add(new RowModel(key, mRowModel.get(key)));
    }
    return rowModels;
  }