public DataPoint addDataPoint(Object label) {
        DataPoint dp = new DataPoint();
        labels.add(label);
        dataPoints.add(dp);
        return dp;
    }
@Test
    public void testAddDataPoint() {
        cm = new ChartModel(FOO, BAR, ZOO);

        long time = System.currentTimeMillis();

        cm.addDataPoint(time)
                .data(FOO, VALUES1[0])
                .data(BAR, VALUES2[0])
                .data(ZOO, VALUES3[0]);

        cm.addDataPoint(time + 1)
                .data(FOO, VALUES1[1])
                .data(BAR, VALUES2[1])
                .data(ZOO, VALUES3[1]);

        cm.addDataPoint(time + 2)
                .data(FOO, VALUES1[2])
                .data(BAR, VALUES2[2])
                .data(ZOO, VALUES3[2]);

        assertEquals("Wrong result", 3, cm.getDataPoints()[0].size());
        assertEquals("Wrong result", 3, cm.getDataPoints()[1].size());
        assertEquals("Wrong result", 3, cm.getDataPoints()[2].size());
        assertEquals("Wrong result", 3, cm.getDataPoints().length);
    }