Vaadin Charts where only last data point has a label

LastPointChart.java

package com.jensjansson;

import com.vaadin.addon.charts.Chart;
import com.vaadin.addon.charts.model.*;

public class LastPointChart extends Chart {

    public LastPointChart() {
        Configuration conf = getConfiguration();
        setConfiguration(conf);
        conf.getxAxis().setCategories("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
        PlotOptionsLine po = new PlotOptionsLine();
        conf.setPlotOptions(po);
        DataLabels labels = new DataLabels();
        po.setDataLabels(labels);
        labels.setEnabled(true);
        labels.setAlign(HorizontalAlign.LEFT);
        labels.setFormatter(
                "function() { " +
                "  if(this.point.x == this.series.data.length - 1) { " +
                "    return this.y; " +
                "  } else { " +
                "    return null; " +
                "  } " +
                "}" );

        labels.setCrop(false);
        labels.setOverflow("false");


        ListSeries series1 = new ListSeries(29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4);
        ListSeries series2 = new ListSeries(106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4, 29.9, 71.5);
        conf.addSeries(series1);
        conf.addSeries(series2);
    }
}