title: Change label of donut chart in c3js
body: <p>I've used setting label on start and its working, here is the working code:</p>
  
  <pre><code>var chartDonut1 = c3.generate({
      data: {
          columns: [
              ['data1', 30],
              ['data2', 120],
          ],
          type : 'donut'
      },
      donut: {
          title: "title"
      }
  });
  </code></pre>
  
  <p>But, i want to change the label on the donut based on search, and for that purpose i need to use <code>load</code> function.  </p>
  
  <p>EDIT:
  Here is example of donut chart and with title: <a href="http://c3js.org/samples/chart_donut.html" rel="nofollow">LINK</a></p>
  
  <p>How can label be change/set on load? </p>
  
  <p>I've tried setting like code bellow, but i can't make it work: </p>
  
  <pre><code>chartDonut1.load({
      json: dataJsonGraph,
      donut: {
          title: 'title1', 
      },
      bindto: '#chartDonut1'                              
  });
  </code></pre>
  
  <p>Any suggestion will be great!</p>