title: Click event for Stacked Area Chart in C3js
body: <p>I have a stacked area chart and i need each area should be clickable and based on the area clicked data1/data2/data3 respective route will be done.</p>
  
  <p>If I set data.selection.grouped = true, I am able to click on the whole area but the click event is getting triggered for all data(data1, data2 and data3).</p>
  
  <p>If I set data.selection.grouped = false, Click is available only on the data point, but I need the whole area should be clickable.</p>
  
  <p>Please let me know how can i achieve this.</p>