Google圆环图标将图例标记为html而不是字符串

Question

我可以为谷歌图表的传说添加自定义HTML吗？我想为每个部分添加额外的信息和图标，而不仅仅是文本。

我添加了这个jsFiddle示例

google.setOnLoadCallback(drawChart);
function drawChart() {

    var data = google.visualization.arrayToDataTable([
      ['Source', 'Amount given'],
      ['organic',     50],
        ['direct', 30],
        ['referral', 15],
        ['paid', 5]
    ]);

    var options = {
      pieHole: 0.6,
      legend: 'labeled',
      pieSliceTextStyle: {
        color: '#fff',
      },

        pieSliceText: 'percentage',
        slices: {0: {color: '#27ae60'},
                 1:{color:'#2980b9'},
                 2:{color:'#57C0E8'},
                 3: {color: 'bdc3c7'}}
    };

    var chart = new google.visualization.PieChart(document.getElementById('donut_single'));
    chart.draw(data, options);
  }