如何从jfree图表中删除切片部分标记

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.general.DefaultPieDataset;

DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("标记1", 30);
dataset.setValue("标记2", 40);
dataset.setValue("标记3", 20);
dataset.setValue("标记4", 10);

JFreeChart chart = ChartFactory.createPieChart("图表标题", dataset, true, true, false);

PiePlot plot = (PiePlot) chart.getPlot();

plot.setLabelLinksVisible(false);

ChartFrame frame = new ChartFrame("图表标题", chart);
frame.pack();
frame.setVisible(true);