private static CategoryDataset createDataset(DataHolder dataHolder,
            List<String> timeLines, GCDataType gcDataType) {

        Map<String, TreeMap<String, GCData>> datas = dataHolder.datas
                .get(gcDataType);

        DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        for (int i = 0; i < timeLines.size(); i++) {
            String time = timeLines.get(i);
            for (String event : datas.keySet()) {
                TreeMap<String, GCData> map = datas.get(event);
                for (Entry<String, GCData> entry : map.entrySet()) {
                    if (entry.getKey().equals(time)) {
                        dataset.addValue(entry.getValue().getValue(), event,
                                entry.getKey());
                    }
                }
            }
        }
        return dataset;
    }