title: How can i add an image in nvd3 piechart legend?
body: <p>I want to add an image in nvd3 piechart legend instead of text.
  I have this code but it changes only the text in the tooltip with the image. I want to change and the text in the legend with the same image.</p>
  
  <pre><code>var testdata = [
  {
    key: "&lt;img src="+"./imgs/facebook.jpg"+"&gt;",
    y: 1
  },
  {
    key: ""&lt;img src="+"./imgs/twitter.jpg"+"&gt;"",
    y: 2 
  }  ];
  nv.addGraph(function() { 
  
  var chart = nv.models.pieChart()
      .x(function(d) { return d.key})
      .labelThreshold(.08)
      .showLabels(true)
      .color(d3.scale.category10().range())
      .donut(true);
  
  
  
    chart.pie.donutLabelsOutside(true).donut(true);
  
    d3.select("#mypiechart")
      .datum(testdata)
      .transition().duration(1200)
      .call(chart);
  
  return chart;});
  </code></pre>
  
  <p>Any ideas?</p>